Stabilizing Binoculars
f...@fff.com
work for night sky oberserving although I have been thinking about getting a
pair for my use on my boat. Anyway, I saw an ad in Astronomy magazine for
Canon's image stabalizing binoculars and the ad was geared for moon gazing.
Thanks,
Ned
Jim Robinson
Check around before buying, the price varys a lot. I just bought a pair of
10x30's for my dad, the prices quoted ranged from $340 - $550.
Jim
Warren Porter
>
> Has anybody tried image stabalizing binoculars? I was not sure if this would
> work for night sky oberserving although I have been thinking about getting a
> pair for my use on my boat. Anyway, I saw an ad in Astronomy magazine for
> Canon's image stabalizing binoculars and the ad was geared for moon gazing.
>
> Thanks,
>
1. They are like regular binoculars until you press the
stabilizaiton button. Then your shaky grip becomes less apparent.
2. The sales person did mention that although they stabilize
the battery life is not long so carry a pocket full of batteries if you
intend to use the stabilizaiton feature.
I bought regular binos and put them opn a tripod, eventually I graduated
to the trapezoidal mount so you can raise and lower them to suit your
comfrot level, and that of incidental observers. Frankly I think if I
was going to put in 400-600 bucks, I would go with some larger diameter
binos and resign myself to using a tripod.
Warren
--
email address: wlpo...@erols.com
MHarveyWW1
first got them I was annoyed by the recurrent vibrations in the stabilizing
prisms that cause star images to slightly blur every few seconds. In time I
came to realize that I was being overly critical - as the benefits of these
binoculars far outweigh any shortcomings in this area!
I have a shelf full of 'traditional' Nikon and Fujinon binoculars that are
now collecting dust since I acquired the Canons. I also sold my 16 X 70 Fujinon
FMT-SX's (which had heretofore been my all-time favorite astronomical
binoculars). The stabilizing effect of the Canons give them performance that
far exceeds what is normal for such an aperture. It's like having the
performance of a 70mm in a hand-held package!
Aside from the stabilizer... the optical quality of the Canons is just short
of the Fujinons and superior to most other top-of the-line models that I've
owned or used.
I use my daily....and that is the best endoresement I can think of.
PS - the battery 'problem' is not as severe as some have suggested. Use the
NIMH re-chargeables and you'll get several weeks of normal use before
recharging.
Mike Harvey
Herm
http://secure.sovietski.com/cgi-bin/Sovietski.storefront/1001092394/Product/View/203802
No batteries, 16*50, work at any angle, long eye relief but they dont mention
weight..
See you at the WSP, if you are coming..
Herm
Walt Bilofsky
> I've had my Canon 15 X 45 stabilized binocs for about a year now. When I
>first got them I was annoyed by the recurrent vibrations in the stabilizing
>prisms that cause star images to slightly blur every few seconds.
I've had Canon 12x36 stabilized binocs for several years. I have
never noticed any vibrations and have been delighted with them. I
mostly use them for terrestrial observation, and recently compared
them with the new Fujinon 15x40 IS which did have a slight constant
jitter. I wonder if the jitter occurs in the 15x but not the 12x? Or
is it a sample defect - do all the Fujinons have it?
The benefit of the Fujinons is that they stabilize through five
degrees as opposed to 1 degree for the Canon - but this is of no
interest in astronomical use, in fact it's annoying when you move the
Fujinons as the image is a bit sloshy in tracking.
I use lithium batteries from Radio Shack in my Canons - the battery
life is supposed to be about 7 times alkalines but they're expensive.
Rechargable is probably the best.
- Walt Bilofsky
Rob Thacker
>Has anybody tried image stabalizing binoculars? I was not sure if this would
>work for night sky oberserving although I have been thinking about getting a
>pair for my use on my boat. Anyway, I saw an ad in Astronomy magazine for
>Canon's image stabalizing binoculars and the ad was geared for moon gazing.
Image-stabilizing binoculars are fine for terrestrial use and
moon-watching. They have small exit pupils, so using them for general
star-gazing is not very good.
For the huge price premium you pay for the stabilization, you'd be
better off to get a decent pair of large binoculars and a compact
monopod.
zgse...@netway.com
>On Fri, 24 Dec 1999 17:12:56 GMT, <f...@fff.com> wrote:
>
>>Has anybody tried image stabalizing binoculars? I was not sure if this would
>>work for night sky oberserving although I have been thinking about getting a
>>pair for my use on my boat. Anyway, I saw an ad in Astronomy magazine for
>>Canon's image stabalizing binoculars and the ad was geared for moon gazing.
>
>Image-stabilizing binoculars are fine for terrestrial use and
>moon-watching. They have small exit pupils, so using them for general
>star-gazing is not very good.
How do you reckon that one out Rob? How large do you imagine the exit
pupil is on your telescope most of the time? Is it less useful for
general stargazing whenever the exit pupil is smaller than 7mm?
Most experienced binocular astronomers prefer the darker sky
background afforded by binoculars that feature higher magnification
(and therefore smaller exit pupils) because they show galaxies,
clusters, and nebulae to better advantage. In fact a pair of 15x45s
(which have a 3mm exit pupil) will show you objects nearly as well as
a pair of 10x70s (with 7mm exit pupils). There is an extensive
discussion of this subject by Roy Bishop in the RASC's annual
Observer's Handbook.
For what it's worth, image-stabilized binoculars are excellent for
observing and most people I know who have owned them would never go
back to ordinary binoculars. I certainly fall into that category.
Regards,
Gary Seronik
(Remove the "z" for my actual e-mail address.)
Rob Thacker
>rtha...@yahoo.com (Rob Thacker) wrote:
>>Image-stabilizing binoculars are fine for terrestrial use and
>>moon-watching. They have small exit pupils, so using them for general
>>star-gazing is not very good.
>
>How do you reckon that one out Rob? How large do you imagine the exit
>pupil is on your telescope most of the time? Is it less useful for
>general stargazing whenever the exit pupil is smaller than 7mm?
If I am aiming for wide-field views of the sky, then yes, it is. But
my scope has a much larger aperture than my 11x70mm binoculars, which
is why I tend to use the 'scope for object-viewing, and not panning
the Milky Way.
>Most experienced binocular astronomers prefer the darker sky
>background afforded by binoculars that feature higher magnification
>(and therefore smaller exit pupils) because they show galaxies,
>clusters, and nebulae to better advantage.
Hmmm... not me. I've tried the high magnification, small exit pupil,
binoculars. To me, the image just looked dim, not better. I can
understand if you're using the binoculars for viewing small objects,
then higher magnification is more important than larger aperture or
brighter views. But, if I want to view objects, I'll use a telescope.
I use binoculars for wide views of open clusters, dark nebulae, the
milky way, and M31 of course.
>In fact a pair of 15x45s
>(which have a 3mm exit pupil) will show you objects nearly as well as
>a pair of 10x70s (with 7mm exit pupils). There is an extensive
>discussion of this subject by Roy Bishop in the RASC's annual
>Observer's Handbook.
Yes, I've read that section. It does assume that the primary purpose
of binoculars is to view specific objects. I just don't think that's
the case; it certainly isn't for me. I use binoculars for star-gazing,
much the same way that I do naked-eye star gazing. If I want to view
galaxies or globulars, I'd much rather use a telescope.
>For what it's worth, image-stabilized binoculars are excellent for
>observing and most people I know who have owned them would never go
>back to ordinary binoculars. I certainly fall into that category.
I'm sure they're fine for viewing bright objects, and I can certainly
see their advantage in daytime use. And if money is no object, then
sure, why not get a pair of 15x45mm stabilized, to compliment the
trusty 7x50mm or 9x63mm.
But if money is a concern, I'd rather get a decent pair of slightly
lower-power giant binoculars (preferably with a wide view), and sink
the rest of the money into a tripod (or monopod, if portability is a
concern).
zgse...@netway.com
>I use binoculars for wide views of open clusters, dark nebulae, the
>milky way, and M31 of course.
Image-stabilized binoculars work very well for these applications.
For example, my Canon 15x45s have a true field of 4.5 degrees -- the
same as your 11x70s (assuming they have the typical 50 deg a.f.
eyepieces). However the Canons, by virtue of their greater
magnification, will provide better resolution and a darker sky
background -- at the same time providing the wide field of view you
enjoy.
>
>But if money is a concern, I'd rather get a decent pair of slightly
>lower-power giant binoculars (preferably with a wide view), and sink
>the rest of the money into a tripod (or monopod, if portability is a
>concern).
If money is a concern, then I agree image-stabilized binoculars are
probably not the best choice -- standard lightweight 10x50s would be
better. However I doubt that a quality pair of 70mm binoculars and
the tripod you would need to go with them is going to save you any
money over image-stabilized binos. Besides, in my opinion, the minute
you have to pack a tripod with you binoculars you have lost one of the
big advantages inherent in the breed.
Rob Thacker
>>I use binoculars for wide views of open clusters, dark nebulae, the
>>milky way, and M31 of course.
>
>Image-stabilized binoculars work very well for these applications.
>For example, my Canon 15x45s have a true field of 4.5 degrees -- the
>same as your 11x70s (assuming they have the typical 50 deg a.f.
>eyepieces).
I didn't realize they were wide-field. That's certainly nice.
>However the Canons, by virtue of their greater
>magnification, will provide better resolution and a darker sky
>background -- at the same time providing the wide field of view you
>enjoy.
Well, darker sky background as well as fainter views of large nebulae
(compared to a 70mm aperture). I've used 16x50mm binocs (tripod
mounted) before; I just didn't like the dark views. For myself, I
prefer a larger aperture and brighter view, over the convenience of
hand-held stabilization. If I could have both, at a reasonable price,
then I'd take it! :-)
>Besides, in my opinion, the minute
>you have to pack a tripod with you binoculars you have lost one of the
>big advantages inherent in the breed.
Well yes, which is why I suggested a monopod. But my 11x70mm binocs
are not that bad, hand held. Laying down in a lawn chair, they're
quite stable. They probably don't weigh anymore than your 15x45mm
stabilized binocs. But, they're certainly improved by using a tripod.
It's a trade-off.
MHarveyWW1
> But my 11x70mm binocs
>are not that bad, hand held. Laying down in a lawn chair, they're
>quite stable.
Hi Rob...
I've owned both the 10 X 70 and 16 X 70 Fujinon FMT-SX's...and now the 15 X 45
Canon stabilized binoculars...so I thought I'd share a couple of observations.
When deepsky observing, I see FAR MORE with the 45mm stabilized binoculars that
I ever saw hand-holding the 10 X 70's.
The 16 X 70's provided MUCH more enjoyable and detailed deepsky views than the
10 X 70's. The additional magnification increases the image scale with no
significant loss of light...and it's sooo much easier to see LARGE faint
objects than SMALL faint objects.
If you ever get the chance, try a pair of either the 16 X 70's or the 15 X
45's. I think you'll be pleasantly surprised.
Mike Harvey
Rob Thacker
>I've owned both the 10 X 70 and 16 X 70 Fujinon FMT-SX's...and now the 15 X 45
>Canon stabilized binoculars...so I thought I'd share a couple of observations.
>
>When deepsky observing, I see FAR MORE with the 45mm stabilized binoculars that
>I ever saw hand-holding the 10 X 70's.
>
>The 16 X 70's provided MUCH more enjoyable and detailed deepsky views than the
>10 X 70's. The additional magnification increases the image scale with no
>significant loss of light...and it's sooo much easier to see LARGE faint
>objects than SMALL faint objects.
>
>If you ever get the chance, try a pair of either the 16 X 70's or the 15 X
>45's. I think you'll be pleasantly surprised.
Interesting. Thanks for the feedback.
Yes, I'd love to try the 15x45mm stabilized binocs. They're just too
expensive right now, for my interest level. I do prefer large exit
pupils for binoculars, as well.
I considered buying 16x70mm binocs, but rejected them because I wanted
something that is possible to hand hold (for quick views, or laying
down). I find that 11x is about as high as I wish to go, and even
there they are much better on a tripod. (My old 16x50mm were just too
powerful for any hand-held viewing.)
If they could make a quality 16x80mm stabilized binoculars for under
$500, I'm there! ;-)
John J. Kasianowicz
the way god intended: with your hands (i.e. w/o a monopod or tripod).
Warning: anyone who flames me for that previous sentence will spend the rest
of their tomorrows in the abyss of Hades. From the usual sources, I
understand that light pollution there is a very severe problem!
Rob Thacker wrote:
[snip]
Robert Berta
mention in either model. The Fujis did have a much wider area of motion before
you "beat" it. It was 5 degrees on the Fujis and about 1 degree on the Canons
as I recall. The problem with both of them is that they are pretty much useless
for astronomy. Too small of a exit pupil. They are also heavy.....any binocualr
used for astronomy is going to tire you out pretty quickly and you really need
to mount them on a tripod or some sort of a bino mount. Once you do that than
the stabilization is a useless item. I would much rather have giant binos like
my Fuji 16x70mm or 7x50 Polaris. Now THOSE are great astronomical binoculars.
If you aren't into astronomy though the stabilization models are pretty nifty.
I would have to lean towards the Fujis since they appear to be the next
generation compared to the Canons. Image wise both are excellent but I favor
the Fujis also.
Bob Berta
Walt Bilofsky <bilo...@toolworks.com> wrote in article
<opic6s4hdslrqp0nk...@4ax.com>...
zgse...@netway.com
>I compared the highest power Canons and Fujinons. Didn't see that jitter you
>mention in either model. The Fujis did have a much wider area of motion before
>you "beat" it. It was 5 degrees on the Fujis and about 1 degree on the Canons
>as I recall. The problem with both of them is that they are pretty much useless
>for astronomy. Too small of a exit pupil.
Where does this myth come from? This is the second time I've read
this here in a week. Does your telescope suddenly become "pretty
much useless for astronomy" when its exit pupil is 3mm? For most
scopes this is regarded as low-medium power.
Most experienced binocular astronomers prefer the darker sky
background afforded by binoculars that feature higher magnification
(and therefore smaller exit pupils) because they show galaxies,
clusters, and nebulae to better advantage. In fact a pair of 15x45s
(which have a 3mm exit pupil) will show you objects nearly as well as
a pair of 10x70s (with 7mm exit pupils). There is an extensive
discussion of this subject by Roy Bishop in the RASC's annual
Observer's Handbook.
Rob Thacker
>"Robert Berta" <RK...@nospam.pge.com> wrote:
>
>>I compared the highest power Canons and Fujinons. Didn't see that jitter you
>>mention in either model. The Fujis did have a much wider area of motion before
>>you "beat" it. It was 5 degrees on the Fujis and about 1 degree on the Canons
>>as I recall. The problem with both of them is that they are pretty much useless
>>for astronomy. Too small of a exit pupil.
>
>Where does this myth come from? This is the second time I've read
>this here in a week. Does your telescope suddenly become "pretty
>much useless for astronomy" when its exit pupil is 3mm? For most
>scopes this is regarded as low-medium power.
Sure, but the primary purpose of a telescope is to magnify a lot. That
is not the primary purpose of binoculars. Binoculars are for bright,
low-power viewing.
>Most experienced binocular astronomers prefer the darker sky
>background afforded by binoculars that feature higher magnification
>(and therefore smaller exit pupils) because they show galaxies,
>clusters, and nebulae to better advantage.
Hmmm... does that make anyone who prefers bright views,
"inexperienced"? High magnification can be nice (especially a
wide-field, stabilized view), but I don't buy your argument that a
dark view shows galaxies better than a bright view. I'd much rather
have a bright 7mm exit pupil at 15x magnification, than a dim 3mm exit
pupil at 15x magnification.
Yes, that's a bit of apples and oranges, but the point is that you are
sacrificing a bright view, in order to get stabilized, hand-held
viewing. A pair of 16x80mm or 11x80mm giant binocs cost less than the
15x45mm stabilized binocs. Both are heavy beasts, and you probably
don't want to hand-hold either of them, all evening long.
>In fact a pair of 15x45s
>(which have a 3mm exit pupil) will show you objects nearly as well as
>a pair of 10x70s (with 7mm exit pupils). There is an extensive
>discussion of this subject by Roy Bishop in the RASC's annual
>Observer's Handbook.
(I already answered this, but perhaps you missed it.)
That section in the RASC handbook assumes that the primary purpose
of binoculars is to view specific objects. I just don't think that's
the case for everyone; it certainly isn't for me. I use binoculars for
star-gazing, much the same way that I do naked-eye star gazing. When I
want to view galaxies or globulars, I use a telescope. (Well, okay,
when traveling, binoculars do make a great super-portable telescope.
In that case, a stabilized high-magnification is certainly desirable.)
Yes, the 15x45mm may show almost as much detail in a galaxy as a pair
of 10x70mm, but there's no way it gives one the same feeling of awe
while panning the milky way from a dark site. If you want high
magnification, a telescope is a better way to go (and cheaper, too).
I don't think there's anything wrong with the current crop of
stabilized binoculars. They have very good astronomical use in limited
circumstances (such as viewing the moon, planets, or bright open
clusters). I just don't think they're as good for all-around
astronomical use, as a pair of 11x70mm or 16x80mm binoculars. (And for
the money, it's hard to beat a good pair of 7x50mm binoculars.)
If you use binoculars for daytime use, then I think the 15x45mm
stabilized binoculars would beat the pants off just about any other
kind. Likewise, if it is impractical to use some kind of support, and
you still want high-power, then stabilized is the way to go.
zgse...@netway.com
>On Thu, 30 Dec 1999 01:28:53 GMT, zgse...@netway.com wrote:
>
>>"Robert Berta" <RK...@nospam.pge.com> wrote:
>>
>>>I compared the highest power Canons and Fujinons. Didn't see that jitter you
>>>mention in either model. The Fujis did have a much wider area of motion before
>>>you "beat" it. It was 5 degrees on the Fujis and about 1 degree on the Canons
>>>as I recall. The problem with both of them is that they are pretty much useless
>>>for astronomy. Too small of a exit pupil.
>>
>>Where does this myth come from? This is the second time I've read
>>this here in a week. Does your telescope suddenly become "pretty
>>much useless for astronomy" when its exit pupil is 3mm? For most
>>scopes this is regarded as low-medium power.
>
>Sure, but the primary purpose of a telescope is to magnify a lot. That
>is not the primary purpose of binoculars. Binoculars are for bright,
>low-power viewing.
I though the primary purpose of binoculars and telescopes was to show
you the night sky better than your naked eye. Binoculars and
telescopes both work exactly the same way and this statement about
small exit pupils rendering a pair of binoculars or a telescope
"pretty much useless" is simply wrong.
You might prefer the view through binocualrs that provide a 7mm exit
pupil, but this is purely a matter of taste -- your preference does
not make binoculars with smaller exit pupils less useful, let alone
"useless" for astronomy. It is a fact that higher power will show
galaxies, clusters, and nebulae, better. Try comparing a pair of 7x50
binoculars to a pair of 10x50s -- the 10x pair will show every
celestial object more plainly that the 7x pair, in spite of having a
smaller exit pupil. In fact, the only advantage a lower-power pair of
binoculars offers is a wider true field. However, as I pointed out to
you earlier in this thread, the Canon image-stabilized binoculars are
a wide-field design so you get the same true field at 15x with these
as you would with an ordinary pair of similar sized binos at lower
power.
Rob, I'm not disputing that you have good reason for preferring the
binoculars that you do, I'm simply arguing that a 3mm exit pupil does
not make a pair of binoculars useless for astronomy.
Rob Thacker
>Rob, I'm not disputing that you have good reason for preferring the
>binoculars that you do, I'm simply arguing that a 3mm exit pupil does
>not make a pair of binoculars useless for astronomy.
(At the risk of beating this thread to death...)
I never claimed that 3mm exit pupil binoculars are useless for
astronomy. I just claim that they are not as good for general-purpose
star-gazing as a larger pair of binoculars (that perhaps magnify a
little less). But if one can afford both kinds, then it's win/win.
High-magnification, small exit-pupil binoculars certainly perform
better in some situations, especially where a bright image is not so
important. And for viewing small targets, higher magnification can be
more important than larger aperture. (But in those cases, I'll take a
telescope over binoculars.)
If extreme portability and viewing small objects is someone's main
goal, then a pair of 15x45mm stabilized binoculars is probably the
best choice. (And you can't beat them for daytime use.)
zgse...@netway.com
rtha...@yahoo.com (Rob Thacker) wrote:
>
>I never claimed that 3mm exit pupil binoculars are useless for
>astronomy. I just claim that they are not as good for general-purpose
>star-gazing as a larger pair of binoculars (that perhaps magnify a
>little less).
Well, originally you said "Image-stabilizing binoculars are fine for
terrestrial use and moon-watching. They have small exit pupils, so
using them for general star-gazing is not very good." I think you can
see how I took your meaning to be a general condemnation, rather than
the expression of a preference. (It was the other Rob who used the
term "useless" by the way.)
>
>High-magnification, small exit-pupil binoculars certainly perform
>better in some situations, especially where a bright image is not so
>important.
You have been insisting that the view through binoculars with smaller
exit pupils is "dimmer" than those with larger exit pupils. I think
you are misunderstanding what is going on, so let me back up a step.
For a given binocular size, exit-pupil diameter and magnification are
related -- higher magnification necessitates as smaller exit pupil.
Does a smaller exit pupil necessarily mean a dimmer image? No.
Let’s look at a specific example, the galaxy M31. For an extended
object, like M31, no pair of binoculars will make the galaxy brighter.
This is the point at which most people go, "huh?" This does not mean,
however, that binoculars will not make the galaxy easier to see. This
sounds like a contradiction until you understand HOW binoculars (or
telescopes, for that matter) make the galaxy easier to see. The
reason M31 will be easier to see in your binoculars than with your
naked eye is because it appears bigger owing to the magnification of
the binoculars. The more magnification you apply, the bigger it will
appear and for the most part, the easier it will be to see. This is
why 10x binoculars show objects more plainly than 7x binoculars in
spite of the smaller exit pupil diameter. In either binocular, the
total amount of light from the galaxy is exactly the same -- it is no
dimmer in one pair than another, only larger.
So is there an upper limit? Why not go to an extreme and have 25x
binoculars? The reason is that in a pair of 25x50 binoculars M31
WOULD appear dimmer. Why? Because the field of view of the binoculars
is now too small to show you the whole galaxy at once – part of its
light is no longer reaching your eyes, it is spilling outside the
field of view. M31 is about 3-degrees across on its long axis, but a
pair of 25x50 binoculars would only give you a true field of about
2-degrees. So you might conclude that these would not make good
astronomy binoculars, but even that is not entirely true. For objects
smaller than 2-degrees across, they would work fine.
If you have read the above carefully, you might have figured out
another advantage to using higher magnification/smaller exit pupil
binoculars -- a darker sky background. If you think of the sky
background as an enormous extended object, you can see why it gets
dimmer as the magnification increases and the exit pupil shrinks. If
fact, this is a good reason to AVOID binoculars with 7mm exit pupils
since they show the sky background as bright as possible.
As Al Nagler summarized in his May 1991 article in Sky & Telescope,
"The bottom line for low power is to frame the subject. In fact, the
best view occurs with the highest power that comfortably includes the
target object . . . higher powers darken the background sky, reveal
fainter stars, and show more detail."
In the May 1992 issue, Alan MacRobert makes another point that
directly addresses your concern when he says, "The amount of light you
get from a star or any other object is governed by the instrument’s
effective aperture -- not its f/ratio or exit-pupil size. Low power
merely squeezes the same light into a smaller area."
Both these concepts are neatly combined in Roy Bishop’s article on
binocular performance that appears in the RASC’s Observer’s Handbook.
In fact, in the 2000 edition he comments specifically on the topic at
hand: "Canon’s new image-stabilized 15x45 binoculars are nearly
equivalent to tripod-mounted 10x70’s with the TRIPLE (his emphasis)
advantage of smaller size, of accommodating observers whose pupils
will not open to 7 mm, and of not requiring a tripod!"
I hope this has clarified things and that you now understand why a
statement like "they have small exit pupils, so using them for general
star-gazing is not very good" is not an accurate assessment. Indeed, I
would argue that 15x45 binoculars are in fact better for "general
astronomy" than big binoculars -- and that, I suspect is where we
probably really disagree.
John J. Kasianowicz
When I want to collect photons, I use a good scope. When I want to browse
star fields, the brighter DSOs and the moon, I take advantage of the freedom
afforded by the IS binoculars.
If I was so inclined, I would not use IS binoculars to competitively hunt
for new comets.
FWIW, I found that the Canon 15x45 IS binoculars were perfectly suited for
observing the last total solar eclipse. I was tempted to take my Traveler
w/me to Romania, but I was a bit concerned about losing such a lovely
instrument in a potential border crossing (if I had to make a dash to
Bulgaria). Despite the Traveler's petite form factor, it and the
accompanying mount and tripod are bulkier and heavier than binocs. If that's
all IS binoculars are used for, they'd be very expensive indeed (but almost
worth it, IMHO).
The difference in cost between comparable aperture IS and non IS binoculars
is ~ $800-900. That's roughly the same total cost as one can of soda
consumed per day for three years.
Rob Thacker wrote:
[snip]
> Yes, stabilized 15x45mm binoculars provide a great portable and
> convenient mini-telescope. But the view is still much dimmer than
> 11x80mm binoculars. The 15x45mm pair is a compromise: it is halfway
> between a general-purpose astronomical binocular, and a telescope.
> You're paying big bucks for the stabilization feature, which
> essentially is for portability and convenience.
[snip]
Rob Thacker
>You have been insisting that the view through binoculars with smaller
>exit pupils is "dimmer" than those with larger exit pupils.
Yes, that is correct. Any instrument with an exit pupil less that the
size of your eye's pupil is dimming the view. For most observers,
that's about 7mm.
>I think
>you are misunderstanding what is going on, so let me back up a step.
>For a given binocular size, exit-pupil diameter and magnification are
>related -- higher magnification necessitates as smaller exit pupil.
Here is where I don't think you're understanding what I'm trying to
say. For the same cost as a 45mm stabilized aperture, I can buy 80mm
or more of (unstabilized) binocular aperture. If I really want the
same 15x magnification, the latter pair will provide a much larger
exit pupil (and thus brighter view).
>Does a smaller exit pupil necessarily mean a dimmer image? No.
Yes, it does.
I understand what you are trying to say. That is, that magnification
plays an important role is being able to see an object. I agree. But
saying that a 3mm exit pupil doesn't give a dimmer view than a 7mm
exit pupil is plain wrong (for nighttime use).
My argument is that the purpose of binoculars (at least for me,
anyway) is not to provide a kind of hand-held telescope, but to allow
the user to brightly view large areas of the sky. 7x50mm binoculars
are ideal for this, and wide-angle 11x80mm even better (although some
kind of support is likely needed, thus sacrificing some portability
and convenience).
[snip]
>This is
>why 10x binoculars show objects more plainly than 7x binoculars in
>spite of the smaller exit pupil diameter. In either binocular, the
>total amount of light from the galaxy is exactly the same -- it is no
>dimmer in one pair than another, only larger.
Yes, it is dimmer in the 10x pair. However, the image is larger and
the background darker, so it is easier to see.
You don't need to convince me of the benefits of magnification.
I understand. But if I wish to view specific objects, I'll use a
telescope, which provides a much higher magnification (and larger
aperture, to boot).
Yes, stabilized 15x45mm binoculars provide a great portable and
convenient mini-telescope. But the view is still much dimmer than
11x80mm binoculars. The 15x45mm pair is a compromise: it is halfway
between a general-purpose astronomical binocular, and a telescope.
You're paying big bucks for the stabilization feature, which
essentially is for portability and convenience.
I like having bright 7mm exit-pupil binoculars, as well as a
telescope. That way, both kinds of viewing are possible: binoculars
for sweeping the milky way and large nebulae, and a telescope for
examining individual objects. If I could afford a pair of stabilized
binoculars, I'd get some, but it's not as high a priority as some
other astronomy stuff.
>If you have read the above carefully, you might have figured out
>another advantage to using higher magnification/smaller exit pupil
>binoculars -- a darker sky background. If you think of the sky
>background as an enormous extended object, you can see why it gets
>dimmer as the magnification increases and the exit pupil shrinks. If
>fact, this is a good reason to AVOID binoculars with 7mm exit pupils
>since they show the sky background as bright as possible.
If you are doing most of your viewing from suburbs or light-polluted
skies, I agree. But in moderately dark skies, a 7mm exit pupil is
marvelous.
>As Al Nagler summarized in his May 1991 article in Sky & Telescope,
>"The bottom line for low power is to frame the subject. In fact, the
>best view occurs with the highest power that comfortably includes the
>target object . . . higher powers darken the background sky, reveal
>fainter stars, and show more detail."
If you are trying to view dim stars, then by all means throw
magnification at it right down to 1mm exit pupil or less. But this has
more to do with telescopic observing, not binocular use.
>Both these concepts are neatly combined in Roy Bishop’s article on
>binocular performance that appears in the RASC’s Observer’s Handbook.
>In fact, in the 2000 edition he comments specifically on the topic at
>hand: "Canon’s new image-stabilized 15x45 binoculars are nearly
>equivalent to tripod-mounted 10x70’s with the TRIPLE (his emphasis)
>advantage of smaller size, of accommodating observers whose pupils
>will not open to 7 mm, and of not requiring a tripod!"
Yes, there are certainly advantages to stabilized binoculars. Cost is
not one of them!
(And again, this article is talking about observing small objects.
Something that is probably more suited to telescopes, not binoculars.)
>I hope this has clarified things and that you now understand why a
>statement like "they have small exit pupils, so using them for general
>star-gazing is not very good" is not an accurate assessment.
I still maintain that for binoculars, it is an accurate assessment.
There are, of course, exceptions to the rule. But for the most part, a
bright view (and large true field) is more important in binoculars
than magnification. For planetary 'scopes, the opposite it true.
>Indeed, I
>would argue that 15x45 binoculars are in fact better for "general
>astronomy" than big binoculars -- and that, I suspect is where we
>probably really disagree.
Yes, I think we'll have to just agree to disagree. When Cannon makes a
pair of light-weight, stabilized, 15x100mm wide-angle binoculars, then
I'll have nothing to complain about. ;-)
Rob Thacker
<sur...@erols.com> wrote:
>I have both. The relatively heavier 11x80s are now closet relics.
Well, if they're not doing anything, you could always mail them to me!
;-)
BTW, are the 11x80s really that much heavier? You'd need a tripod or
monopod for them anyway, so weight is probably not as much of an issue
as convenience.
If convenience and portability is your main concern, then the
stabilized binocs are a good choice. The best binoculars (or
telescopes) are the ones you will actually bother to get out and use.
>When I want to collect photons, I use a good scope. When I want to browse
>star fields, the brighter DSOs and the moon, I take advantage of the freedom
>afforded by the IS binoculars.
Certainly, for the latter two things, stabilized binocs are preferable
because of their high magnification (and the small exit pupil doesn't
matter much for bright targets).
I'd still rather invest the extra several hundred dollars I.S. costs
me, into a giant aperture instead. (And get a pair of 7x50mm for
convenience.)
>If I was so inclined, I would not use IS binoculars to competitively hunt
>for new comets.
>
>FWIW, I found that the Canon 15x45 IS binoculars were perfectly suited for
>observing the last total solar eclipse. I was tempted to take my Traveler
>w/me to Romania, but I was a bit concerned about losing such a lovely
>instrument in a potential border crossing (if I had to make a dash to
>Bulgaria). Despite the Traveler's petite form factor, it and the
>accompanying mount and tripod are bulkier and heavier than binocs. If that's
>all IS binoculars are used for, they'd be very expensive indeed (but almost
>worth it, IMHO).
>
>The difference in cost between comparable aperture IS and non IS binoculars
>is ~ $800-900. That's roughly the same total cost as one can of soda
>consumed per day for three years.
Well, having a bit of Scotch blood in me, I'd invest the $900 at 10%
interest. Then, I'd buy cans of pop (what is this "soda" thing?) in
cases of 24 at about $0.25 per can. That would buy me a lifetime
supply of pop (one per day)!
(Okay, so we're getting a bit off-topic now...)
Hans Lambermont
zgse...@netway.com writes:
snip
> In either binocular, the total amount of light from the galaxy is
> exactly the same
Given that the effective aperture of those binoculars is the same I
presume ... as the number of photons per second from the galaxy that
enter the binocular will be the same.
regards,
Hans Lambermont
--
http://hans.mypage.org/
http://www.chello.nl/~h.lambermont/
Mike Barrs
news:386bd18...@news.netway.com...
> >High-magnification, small exit-pupil binoculars certainly perform
> >better in some situations, especially where a bright image is not so
> >important.
>
> You have been insisting that the view through binoculars with smaller
> exit pupils is "dimmer" than those with larger exit pupils. I think
> you are misunderstanding what is going on, so let me back up a step.
> For a given binocular size, exit-pupil diameter and magnification are
> related -- higher magnification necessitates as smaller exit pupil.
> Does a smaller exit pupil necessarily mean a dimmer image? No.
Rob is comparing different exit pupils for the *same* magnification (i.e.
larger aperture objectives), and he's right.
Under dark skies, your eye pupils open 5mm-9mm, depending on your age and
genetics. Deep sky objects are intrinsically dim, and the term "astronomy
binoculars" usually refers to binoculars that provide 5mm-7mm exit pupils
for seeing dim objects. Comparing two binoculars with the same
magnification, but two different exit pupils (say, 3mm and 5mm), you're
going to get a better deep sky view with the larger exit pupil.
Here's a real world comparison. I've looked through both 20x77mm and
20x100mm binoculars from the same manufacturer. They have the same
magnification, with one throwing a 3.8mm exit pupil and the other throwing a
5mm exit pupil. The 77mm binoculars are good, but they're dimmer in
comparison to the same magnification and more aperture/larger exit pupil in
the 100mm model. My eye easily accommodates the 5mm light circle, and I see
more that way, because my eye is already open to at least 5mm at night.
There is nothing wrong with a 3mm exit pupil if the objective is big enough,
and can collect enough light for your eye to work with. I run 3mm exit
pupils in my 18" Dob all the time. But for small objectives like binoculars
which don't gather that much extra light in the first place, you need to
take advantage of your eye's ability to open a bit wider.
P.S. I'm not denying that image stabilization can be an "effective aperture
increase" compared to hand-holding slightly larger aperture binoculars.
However.... lock 45mm stabilized binoculars down on a tripod and compare
them to 70mm or 100mm binoculars with the same magnification under dark
skies, and you'll see the difference.
Mike Barrs
zgse...@netway.com
><zgse...@netway.com> wrote in message
>news:386bd18...@news.netway.com...
>> Hi Rob:
>>
>> rtha...@yahoo.com (Rob Thacker) wrote:
>> >
>
>> >High-magnification, small exit-pupil binoculars certainly perform
>> >better in some situations, especially where a bright image is not so
>> >important.
>>
>> You have been insisting that the view through binoculars with smaller
>> exit pupils is "dimmer" than those with larger exit pupils. I think
>> you are misunderstanding what is going on, so let me back up a step.
>> For a given binocular size, exit-pupil diameter and magnification are
>> related -- higher magnification necessitates as smaller exit pupil.
>> Does a smaller exit pupil necessarily mean a dimmer image? No.
>
>Rob is comparing different exit pupils for the *same* magnification (i.e.
>larger aperture objectives), and he's right.
Will bigger binoculars show you more than smaller binoculars when the
magnificaiton is the same? Of course they will, nobody is disputing
that. (You'll note in the paragraph you are commenting it does say
"for a given binocular size.") Rob's original statement, which
sparked this particular discussion, was that 15x45 binoculars were
"not very good" for "general stargazing" because of their 3mm exit
pupils.
The only point I'm trying to make here is that for a given binocular
size (aperture), higher magnification (and therefore smaller exit
pupil size) will show you more than lower magnification. The example
I have been using is a comparison between 7x50 and 10x50 binoculars.
>
>for seeing dim objects. Comparing two binoculars with the same
>magnification, but two different exit pupils (say, 3mm and 5mm), you're
>going to get a better deep sky view with the larger exit pupil.
Yes, but not because of the larger exit pupil. The only way you can
keep the magnification fixed and vary the exit pupil size is by having
two different binocular sizes. Naturally the larger pair (which will
have the larger exit pupil if the magnification is fixed) will show
more. Again, nobody is disputing the benefits of aperture. Now the
convenience of big binoculars is another subject...
>
>Here's a real world comparison. I've looked through both 20x77mm and
>20x100mm binoculars from the same manufacturer. They have the same
>magnification, with one throwing a 3.8mm exit pupil and the other throwing a
>5mm exit pupil. The 77mm binoculars are good, but they're dimmer in
>comparison to the same magnification and more aperture/larger exit pupil in
>the 100mm model.
I think this is where both you and Rob are missing the point -- you
are ascribing benefits to exit-pupil diameter which are really the
result of aperture.
If what Rob had originally said was that smaller image-stabilized
binoculars are not as good for astronomy as larger binoculars, then he
would have been making a statement of personal preference, which is
really what this all boils down to in the end. He prefers (if I read
him correctly) the view in big binoculars with a 7mm exit pupil to the
view in smaller binoculars, even when they have greater magnification.
Nothing wrong with that.
zgse...@netway.com
>
>You don't need to convince me of the benefits of magnification.
>I understand. But if I wish to view specific objects, I'll use a
>telescope, which provides a much higher magnification (and larger
>aperture, to boot).
Now hang on Rob, a pair of 15x45s will no more force you to view a
"specific object" than your favorite choice, 11x80s(?) -- which strike
me as a much more specialized pair of binoculars than the 15x45s.
The ONLY statement of yours I really take issue with is your original
claim that binoculars with 3mm exit pupils are "not very good" for
general stargazing. They are excellent for general stargazing -- which
is what I use mine for all the time.
>You're paying big bucks for the stabilization feature, which
>essentially is for portability and convenience.
Isn't portability and convenience the main point of binoculars? It
certainly is for me. When it comes to the Canons, you're not just
paying for the stabilization feature, you're also paying for superb
wide-field optics too.
>
>I like having bright 7mm exit-pupil binoculars, as well as a
>telescope.
Nothing wrong with that except that I can't think of a single object
in the night sky that looks better in 7x50s than 10x50 binoculars.
>
>>If you have read the above carefully, you might have figured out
>>another advantage to using higher magnification/smaller exit pupil
>>binoculars -- a darker sky background. If you think of the sky
>>background as an enormous extended object, you can see why it gets
>>dimmer as the magnification increases and the exit pupil shrinks. If
>>fact, this is a good reason to AVOID binoculars with 7mm exit pupils
>>since they show the sky background as bright as possible.
>
>If you are doing most of your viewing from suburbs or light-polluted
>skies, I agree. But in moderately dark skies, a 7mm exit pupil is
>marvelous.
>
The sky is never black. The advantage of a smaller exit pupil holds
even under the best skies. BTW -- you place a high value in this 7mm
exit pupil, how sure are you that your pupils open that wide?
>>As Al Nagler summarized in his May 1991 article in Sky & Telescope,
>>"The bottom line for low power is to frame the subject. In fact, the
>>best view occurs with the highest power that comfortably includes the
>>target object . . . higher powers darken the background sky, reveal
>>fainter stars, and show more detail."
>
>If you are trying to view dim stars, then by all means throw
>magnification at it right down to 1mm exit pupil or less. But this has
>more to do with telescopic observing, not binocular use.
No, it has to do with observing the night sky -- regardless of
instrumentation. Read it again carefully -- he is not talking just
about dim stars or small objects. Nagler's statement is equally true
for binoculars.
>
>(And again, this article is talking about observing small objects.
>Something that is probably more suited to telescopes, not binoculars.)
No it isn't. Read the it again. The article is about "the ability to
reveal detail in the night sky."
>
>>Indeed, I
>>would argue that 15x45 binoculars are in fact better for "general
>>astronomy" than big binoculars -- and that, I suspect is where we
>>probably really disagree.
>
>Yes, I think we'll have to just agree to disagree. When Cannon makes a
>pair of light-weight, stabilized, 15x100mm wide-angle binoculars, then
>I'll have nothing to complain about. ;-)
You'll still complain about the cost -- trust me. ;-)
Rob Thacker
>Now hang on Rob, a pair of 15x45s will no more force you to view a
>"specific object" than your favorite choice, 11x80s(?) -- which strike
>me as a much more specialized pair of binoculars than the 15x45s.
Well, they're specialized for astronomy more than the 15x45s, yes.
For a general purpose day & night binocular, the I.S. 15x45s are
probably better. I'd certainly rather have the stabilized pair, for
daytime spotting, no doubt about it.
>The ONLY statement of yours I really take issue with is your original
>claim that binoculars with 3mm exit pupils are "not very good" for
>general stargazing. They are excellent for general stargazing -- which
>is what I use mine for all the time.
We're just going to have to disagree, here. I find 3mm exit pupils
provide too dim a view, for my taste, in binoculars. Yes, you may be
able to see a lot with them, due to the high magnification, but the
view is simply not as pleasing as a bright image.
>>You're paying big bucks for the stabilization feature, which
>>essentially is for portability and convenience.
>
>Isn't portability and convenience the main point of binoculars? It
>certainly is for me.
For some, that's certainly true. As I said, if that's your main
concern, then the I.S. is probably the way to go.
>>I like having bright 7mm exit-pupil binoculars, as well as a
>>telescope.
>
>Nothing wrong with that except that I can't think of a single object
>in the night sky that looks better in 7x50s than 10x50 binoculars.
Well, you're showing your bias toward "object" viewing, rather than
general stargazing. If object viewing is your main purpose, then
higher magnification may be more important than a larger aperture.
But, I'm not comparing a pair of 7x50mm to 10x50mm. I'm comparing a
pair of 15x45mm to a pair of 11x80mm (costing about the same as the
I.S. pair). I think the 11x80mm will not only allow you to see more
detail in dim "objects", but will provide a more pleasing view for
general stargazing (such as sweeping the milky way). The only
advantage the 15x45mm has is the stabilized hand-held view. (And I
don't dispute that it's not an important advantage. But I can get a
stable view using some kind of manual support, too.)
>The sky is never black. The advantage of a smaller exit pupil holds
>even under the best skies. BTW -- you place a high value in this 7mm
>exit pupil, how sure are you that your pupils open that wide?
I measured them, before buying. They open about 8mm. I figure I have a
few years before they get smaller than 7mm.
>No it isn't. Read the it again. The article is about "the ability to
>reveal detail in the night sky."
Sure, but for that purpose, I'll use a telescope!
>You'll still complain about the cost -- trust me. ;-)
Okay, Cannon should make them free. Then, I'll get at least one pair!
John J. Kasianowicz
I might sell the 11x80s someday for a very fair price.
They are heavier and longer than the 15x45 IS binocs. Unless I place my
hands in a very uncomfortable position, the 11x80s exert more torque on my
wrists. That will, of course, vary from person to person. To me, the idea of
using a tripod for binoculars seems inconsistent with their implied promise
of portability. If I'm going to use a tripod, I might as well use a quality
wide-field scope w/a larger aperture.
1 can of pop per day and 24 cans of pop, that means you're only planning on
living for less than a month. Snap out of it!! Life is worth living! ~8^)
All kidding aside, I merely brought up the "pop" thing because I hear many
folks gripe about how much first-rate optics cost. Frankly, many good
instruments are bargains, particularly when you compare what they would cost
if you factor in the strength of the some economies.
Rob Thacker wrote:
> Well, if they're not doing anything, you could always mail them to me!
> ;-)
>
> BTW, are the 11x80s really that much heavier? You'd need a tripod or
> monopod for them anyway, so weight is probably not as much of an issue
> as convenience.
[snip]
John J. Kasianowicz
light and yield better resolution. However, to me, the real beauty of
binoculars is their wide-fields, portability (which precludes lugging a
tripod) and ease of use (IMO, unless you're comet hunting, tripods make
binocs less desirable to use).
William R. Meyers
Hi Gary,
You guys are saying that for a given binocular magnification, larger
aperture shows objects better, and for a given binocular aperture, higher
magnification shows objects better. Yes?
zgse...@netway.com wrote:
zgse...@netway.com
>
>Hi Gary,
> You guys are saying that for a given binocular magnification, larger
>aperture shows objects better, and for a given binocular aperture, higher
>magnification shows objects better. Yes?
In a nutshell, yes. (Gee, it sounds so obvious when you put it like
that!) However there are subtle aspects that enter into the equation
when you diverge from these narrow specifics. I recommend having a
look at Alan MacRobert's articles on the S&T web site on this subject.
(www.skypub.com -- look under "Tips" for "Binoculars.")
One subtlety is that 15x45 binoculars will show things nearly as well
as 10x70s. This is a function of the binocular visibility factor that
Bishop talks about in the RASC Observer's Handbook and MacRobert
elaborates upon in his article "Power and Aperture in Binoculars." I
spend a fair amount of time doing binocular astronomy and can vouch
for their claims. When I'm making observations for "Binocular
Highlight," I always make sure to use at least three different pairs
of binoculars to observe whatever I'm going to write about. Over
time, I have come to the opinion that the " best" binoculars for
astronomy are those that can be hand held and offer the highest
magnification while retaining the largest true field desired.
Another aspect of this discussion is that different people want
binoculars for different reasons. Rob and I had a lengthy discussion
and I think most of it revolved around this simple point. Whereas I
like binoculars for their easy portability, convenience and wide-field
views, Rob likes a 7mm exit pupil and doesn't mind using a tripod to
steady his big binoculars -- consequently, we disagree on what
constitutes the "ideal" pair of binoculars.
Hope this helps clarify things.
Rob Thacker
>Another aspect of this discussion is that different people want
>binoculars for different reasons. Rob and I had a lengthy discussion
>and I think most of it revolved around this simple point. Whereas I
>like binoculars for their easy portability, convenience and wide-field
>views, Rob likes a 7mm exit pupil and doesn't mind using a tripod to
>steady his big binoculars -- consequently, we disagree on what
>constitutes the "ideal" pair of binoculars.
Yes, that pretty much sums up my position. I don't mind sacrificing
portability to get larger astronomical binoculars, since I tend to
observe for long periods of time in one physical location that is easy
to get to.
For daytime binoculars, the exact opposite it true. I tend to use
binoculars when I'm hiking, and for brief periods of time. For that,
portability is my prime concern. (And I.S. would be a huge plus,
here.)
Mike Barrs
news:386d1d8e...@news.netway.com...
<snip>
> Will bigger binoculars show you more than smaller binoculars when the
> magnificaiton is the same? Of course they will, nobody is disputing
> that. (You'll note in the paragraph you are commenting it does say
> "for a given binocular size.") Rob's original statement, which
> sparked this particular discussion, was that 15x45 binoculars were
> "not very good" for "general stargazing" because of their 3mm exit
> pupils.
Yes, and I agree with Rob's statement. A 3mm exit pupil would probably not
be most people's choice for general stargazing with small binoculars, unless
you're under heavily light polluted skies where your pupil only opens to 2mm
or 3mm.
> The only point I'm trying to make here is that for a given binocular
> size (aperture), higher magnification (and therefore smaller exit
> pupil size) will show you more than lower magnification.
Yes, that's a general principle in amateur astronomy. More magnification
darkens the sky, it increases contrast, and it enlarges features so your eye
can see them better. But that general principle falls apart when you apply
it to very small objectives (30mm-41mm). Your eyes need all the help they
can get with a small aperture like that. When your eye is open to 5mm or
larger at night, then you're just wasting photons if you don't use these
small binoculars with at least a 5mm exit pupil.
Ignoring the image stabilization issue for the moment (which is basically
just a convenience for replacing a tripod, and doesn't have anything to do
with optics), I just don't think 3mm exit pupils make any sense for
binocular astronomy under reasonably dark skies.
> The example
> I have been using is a comparison between 7x50 and 10x50 binoculars.
And in that example, you're right. More magnification may help you see more
in the 10x50's compared to the 7x50's. But in this case we're comparing
binoculars with 7mm and 5mm exit pupils. Neither of those binoculars has a
3mm exit pupil.
Mike Barrs
Mike Barrs
news:84krse$scv$1...@bob.news.rcn.net...
> There's no question that the larger aperture binoculars will gather more
> light and yield better resolution. However, to me, the real beauty of
> binoculars is their wide-fields, portability (which precludes lugging a
> tripod) and ease of use (IMO, unless you're comet hunting, tripods make
> binocs less desirable to use).
>
Yeah.... I've noticed people do tend to divide sharply along that line of
"hand-held vs. tripod-mounted", when it comes to astronomy binoculars. :-)
I can certainly understand the hand-held preference. It's nice to have at
least one thing in this hobby that's simple to use, affordable, and doesn't
take a half-hour to set up. Why complicate things unecessarily?
I guess I'm a masochist or something... but I don't mind dragging around
heavy gear that takes a few minutes to set up, if it gives me better views.
Convenience and portability are nice, but we're still stuck with the
fundamental aperture limitations of the human eye.
Now, if Fujinon or Canon can come out with some stabilized 70mm or 80mm
binos that weight no more than standard models (hah!), THEN we'll really
have something. ;-)
Actually, I think this problem will eventually be solved from the other
direction, with much better versions of realtime CCD image amplifiers than
we have now. If electronic/digital image enhancement gets to the point where
it's indistinguishable from an optical view (which I believe will happen,
eventually), then we can stop dragging all this big glass around. Until
then, I'm a believer in the big glass.
Mike Barrs
John J. Kasianowicz
> Yeah.... I've noticed people do tend to divide sharply along that line of
> "hand-held vs. tripod-mounted", when it comes to astronomy binoculars. :-)
> I can certainly understand the hand-held preference. It's nice to have at
> least one thing in this hobby that's simple to use, affordable, and
doesn't
> take a half-hour to set up. Why complicate things unecessarily?
I am not completely on the "no-tripod" camp. However, the convenience of
being able to use binoculars w/o other equipment does tend to justify the
expense of IS technology.
> I guess I'm a masochist or something... but I don't mind dragging around
> heavy gear that takes a few minutes to set up, if it gives me better
views.
> Convenience and portability are nice, but we're still stuck with the
> fundamental aperture limitations of the human eye.
That's cool. However, if you're going on a trip, compact and relatively
lightweight IS binoculars are a great alternative to lugging a suite of
"astro" equipment. The IS binoculars can also double for daytime use. Large
binocs and most scopes can't serve both tasks (the AP StowAway is the
highest quality exception but like large binocs, it needs a tripod).
> Now, if Fujinon or Canon can come out with some stabilized 70mm or 80mm
> binos that weight no more than standard models (hah!), THEN we'll really
> have something. ;-)
That would be interesting indeed. However, they'd probably be a bit too
heavy for anything but very short observing sessions (the 15x45s seem to be
on the edge, weight-wise). Alternatively, we could pump iron to strengthen
our arms (ugh).
> Actually, I think this problem will eventually be solved from the other
> direction, with much better versions of realtime CCD image amplifiers than
> we have now. If electronic/digital image enhancement gets to the point
where
> it's indistinguishable from an optical view (which I believe will happen,
> eventually), then we can stop dragging all this big glass around. Until
> then, I'm a believer in the big glass.
Big glass rocks, indeed!
Harald Lang
Mike Barrs wrote:
>>
Yes, that's a general principle in amateur astronomy. More magnification
darkens the sky, it increases contrast, and it enlarges features so your
eye can see them better.
<<
Actually, the contrast remains unchanged (for extended objects),
since the object and the background are darkened to the same degree. But
the contrast _appears_ to have increased because of the larger scale,
which makes low contrast easier to detect.
>>
But that general principle falls apart when you apply it to very small
objectives (30mm-41mm). Your eyes need all the help they can get with a
small aperture like that. When your eye is open to 5mm or larger at
night, then you're just wasting photons if you don't use these small
binoculars with at least a 5mm exit pupil.
<<
I haven't seen any evidence for this principle to fall apart for
small apertures. And you don't lose any photons by having a smaller exit
pupil.
I think it all boils down to what kind of observing you want to do.
Jay Freeman used a 55mm refractor to observe the Herschel 400 list, and
used an exit pupil of about 1.5mm. I don't think he would have used
smaller magnification had he used a 55mm double refractor, i.e., a 55mm
binocular. So a small exit pupil can certainly be useful also with small
apertures.
Cheers -- Harald
Mike Barrs
news:386FB398...@deleteme.math.kth.se...
>
> Mike Barrs wrote:
>
> >>
> Yes, that's a general principle in amateur astronomy. More magnification
> darkens the sky, it increases contrast, and it enlarges features so your
> eye can see them better.
> <<
>
> Actually, the contrast remains unchanged (for extended objects),
> since the object and the background are darkened to the same degree. But
> the contrast _appears_ to have increased because of the larger scale,
> which makes low contrast easier to detect.
Yes, you're right. That's a better way to describe it.
> But that general principle falls apart when you apply it to very small
> objectives (30mm-41mm). Your eyes need all the help they can get with a
> small aperture like that. When your eye is open to 5mm or larger at
> night, then you're just wasting photons if you don't use these small
> binoculars with at least a 5mm exit pupil.
>
> I haven't seen any evidence for this principle to fall apart for
> small apertures.
Well, I don't have any hard evidence, just anecdotal evidence and personal
experience. I've never preferred a 3mm exit pupil through small binoculars
for astronomy, if I could get something bigger at the same magnification.
> And you don't lose any photons by having a smaller exit
> pupil.
We must be talking about different things. If you take two binoculars with
the same magnification, one with 3mm exit pupil and the other with 5mm exit
pupil (i.e. one binocular is larger aperture than the other), and assume
your eye opens to at least 5mm-7mm under dark sky conditions, then you have
to be losing photons with the smaller aperture/smaller exit pupil.
> I think it all boils down to what kind of observing you want to do.
> Jay Freeman used a 55mm refractor to observe the Herschel 400 list, and
> used an exit pupil of about 1.5mm. I don't think he would have used
> smaller magnification had he used a 55mm double refractor, i.e., a 55mm
> binocular. So a small exit pupil can certainly be useful also with small
> apertures.
Yes, and you can row across the Atlantic Ocean in a 6' rowboat if you're
crazy enough. ;-) That doesn't mean it's the best way to cross the ocean.
I admire what Jay has managed to do with a small scope, but I don't think he
would advocate running a 1.5mm exit pupil with a 55mm refractor as the best
way to observe the Herschel 400. I certainly wouldn't. It's possible, but
it's not exactly a comfortable, easy, and fun way to do it. People who take
on unusual challenges for the sake of the challenge, are not good examples
for general discussion.
Mike Barrs
Mike Barrs
news:84oul5$mk0$1...@nntp1.atl.mindspring.net...
Hi Jay,
I agree with what you say about galaxy observing, but we've drifted off
topic. Most people wouldn't try to do the Herschel 400 with binoculars,
because they are fixed magnification instruments. You can't get a 1.5mm exit
pupil in binoculars even if you wanted to. And yes, I do use exit pupils as
small as 1mm or 2mm when I'm observing galaxies. But that's in an 18" scope,
not something with a 2" aperture.
Back to the original point... this branch of the thread started when Rob
said that a 3mm exit pupil was too small for astronomy binoculars (or words
to that effect), and I agree with that. Binoculars are dedicated wide angle
instruments, and they work best with larger exit pupils (assuming a dark sky
observing location). Most people would only choose a binocular with a small
3mm exit pupil for some special, unusual reason... like you're lusting after
APO binoculars but you can only afford the small, high-power Takahashi's, or
because you want image stabilization and it's not available in anything but
a high power/small aperture combination.
I hate to keep belaboring the point, but I'll say one more thing and then
leave this for a while. The optical designers for Fujinon, Miyauchi, and
Nikon are not stupid. They design their dedicated astronomy binoculars with
exit pupils in the 5mm-7mm range. This includes smaller, more portable
models... not just the big guns. That's because this is the range of exit
pupils that works the best. If 3mm (or 2mm, or 1mm) was a desirable exit
pupil for astronomy binoculars, then you would see more binoculars like this
on the market (seems kind of obvious, doesn't it?). As it is, you only see
3mm exit pupils in oddball binoculars, like the Tak APO's or the Canon IS
series. None of the "best" astronomy binoculars have small exit pupils like
this.
Mike Barrs
> I have little experience with binoculars which have
> easy means of varying the magnification over wide limits, but what I do
> have suggests that the right magnifications for seeing a given class of
> object with a given aperture, does not depend much on whether you are
> using a binocular or a simple telescope. I would have started my H400
> survey at a 1.5 mm exit pupil and expected that to be the right one.
>
> > I admire what Jay has managed to do with a small scope, but I don't
> > think he would advocate running a 1.5mm exit pupil with a 55mm
> > refractor as the best way to observe the Herschel 400.
>
> Careful, there are two points mixed up here. I would certainly
> advocate more aperture for easier viewing of the Herschel 400 objects,
> but with the exception of a few very low surface-brightness nebulae, I
> found by actual experiment that a 1.5 mm exit pupil made it easier to
> see these objects in my 55 mm refractor than did either a substantially
> larger or a substantially smaller exit pupil. Given that I had decided
> to try the H400 list with a tiny telescope, I selected a 1.5 mm exit
> pupil because that exit pupil gave me the best chance of seeing those
> objects. The 1.5 mm exit pupil was not something to make it tougher;
> the 1.5 mm exit pupil was to make finding the H400 objects with a 55 mm
> telescope as easy as possible. In other experiments, I have found a 1.5
> mm exit pupil best for those objects with telescopes of many other
> sizes, up through 14-inch clear aperture.
>
> > I certainly wouldn't. It's possible, but it's not exactly a
> > comfortable, easy, and fun way to do it. People who take on unusual
> > challenges for the sake of the challenge, are not good examples for
> > general discussion.
>
> Your mileage may vary, but I recommend you try exit pupils in
> the range 1 to 2 mm for observations of galaxies with any aperture.
> Perhaps you will be as surprised as I was, at how much better they
> work than do larger exit pupils. In any case, the only way to make
> sure you are using the best magnification from those that you have,
> is to try them all.
>
> --
>
> Jay Reynolds Freeman -- freeman at netcom dot com -- I speak only for
myself.
Jay Reynolds Freeman
incomplete version may have gotten out.]
> > Yes, that's a general principle in amateur astronomy. More magnification
> > darkens the sky, it increases contrast, and it enlarges features so your
> > eye can see them better.
>
> Actually, the contrast remains unchanged (for extended objects),
> since the object and the background are darkened to the same degree. But
> the contrast _appears_ to have increased because of the larger scale,
> which makes low contrast easier to detect.
The perception of contrast by the human eye and brain appears to be
complicated. If you could magnify a faint image without changing any
brightness levels, then the larger size of things would almost certainly
make everything easier to see, except for things so big they more than
filled the field of view. The condition "magnify without changing any
brightness levels" is what happens when you change telescope aperture
and magnification in the same proportion, say, by going from a 5-inch at
50x to a 10-inch at 100x. However, if you increase magnification on a
given telescope, then as the image gets larger, the surface brightnesses
of its various parts all diminish -- you have the same total number of
photons spread over a wider area of your retina -- and there comes a
point when the resulting brightnesses begin to be simply too faint to
see at all! Thus there is a tradeoff between the advantages and
disadvantages of increasing magnification on a given telescope, which
may be different for different objects, different observers, and
different sky conditions.
> > But that general principle falls apart when you apply it to very small
> > objectives (30mm-41mm). Your eyes need all the help they can get with a
> > small aperture like that. When your eye is open to 5mm or larger at
> > night, then you're just wasting photons if you don't use these small
> > binoculars with at least a 5mm exit pupil.
As long as your pupil diameter exceeds the exit pupil diameter of the
instrument, no photons are being wasted -- they all go into your eye --
all you are doing is changing the tradeoff that I just mentioned, as you
vary the magnification. I have always considered binoculars to be
special-purpose instruments, optimized for particularly wide fields and
for particularly low surface-brightness objects. In my experience, the
limiting magnitude of binocular-sized instruments for stars and for many
of the higher surface-brightness deep sky objects, will increase -- you
can see fainter objects -- as you increase magnification above the low
values that produce such large exit pupils, while holding aperture
constant.
> > And you don't lose any photons by having a smaller exit
> > pupil.
>
> We must be talking about different things. If you take two binoculars with
> the same magnification, one with 3mm exit pupil and the other with 5mm exit
> pupil (i.e. one binocular is larger aperture than the other), and assume
> your eye opens to at least 5mm-7mm under dark sky conditions, then you have
> To be losing photons with the smaller aperture/smaller exit pupil.
It looks like you are indeed talking about different things, for if
two binoculars have the same magnification and different exit pupils, then
their clear apertures will be different, and the one with the largest
exit pupil will have the greatest clear aperture (clear aperture is equal
to exit pupil times magnification), and gather the most light.
If, however, the two binoculars have the same clear aperture, and your
eye can capture the entire exit pupil, you get the same number of
photons to the retina without regard to exit pupil size.
> > I think it all boils down to what kind of observing you want to do.
> > Jay Freeman used a 55mm refractor to observe the Herschel 400 list, and
> > used an exit pupil of about 1.5mm. I don't think he would have used
> > smaller magnification had he used a 55mm double refractor, i.e., a 55mm
> > binocular. So a small exit pupil can certainly be useful also with small
> > apertures.
That is correct. I have little experience with binoculars which have
Jay Reynolds Freeman
>
> [useful post snipped]
I have always been a little surprised that more astronomical binocular
manufacturers don't produce units with interchangeable eyepieces. Vixen
has an 80 mm built that way, which is a step in the right direction, but
the new model of the 125 mm uses zoom eyepieces to vary magnification in
the range 25x to 75x, which seems to me rather to sidestep the issue. I
think it would be useful to have smaller binoculars with interchangeable
eyepieces, perhaps with apertures as small as 50 mm.
Harald Lang
Mike Barrs wrote:
<<
The optical designers for Fujinon, Miyauchi, and Nikon are not
stupid. They design their dedicated astronomy binoculars with
exit pupils in the 5mm-7mm range. This includes smaller, more
portable models... not just the big guns. That's because this is
the range of exit pupils that works the best.
>>
I think it's because people want to hand hold their
binoculars, so they want low magnification for that reason --
large aperture (to collect light) and low magnification (for
hand-holdability) ==> large exit pupils. But with IS low
magnification is no longer necessary.
Cheers -- Harald
Rob Thacker
<la...@deleteme.math.kth.se> wrote:
> I think it's because people want to hand hold their
>binoculars, so they want low magnification for that reason --
>large aperture (to collect light) and low magnification (for
>hand-holdability) ==> large exit pupils. But with IS low
>magnification is no longer necessary.
That is probably part of the reason, but I don't think it's all of it.
I have not seen any astronomical binoculars which have less than a 4mm
exit pupil. Even the 100mm giants, which are certainly not
hand-holdable, still have exit pupils of 4mm or greater. (And those
ones are probably targeted towards comet-hunting.)
I don't think the Cannon 15x45mm I.S. binoculars are meant for
astronomy. They're great daytime binoculars, which can also be used
for astronomy in a pinch. (And for some limited cases, like viewing
the moon, planets, or bright doubles, they are very effective. But I'd
still rather use a 'scope on those targets.)
Mike Barrs
> > Hi Jay,
> >
> > [useful post snipped]
>
> I have always been a little surprised that more astronomical binocular
> manufacturers don't produce units with interchangeable eyepieces. Vixen
> has an 80 mm built that way, which is a step in the right direction,
That BT80 model is one step forward for gaining more magnification, but it's
two steps backwards for widefield views. It uses 1.25" eyepieces and
tele-extenders that stretch the focal length, so the maximum field is only
1.1 degrees. The exit pupil is probably somewhere around 2mm-3mm. It's an
interesting idea, but it's very tough to get a wide enough binocular field
by stacking two telescopes together. Widefield telescope eyepieces
(especially 2" models) don't fit the interocular adjustment requirements for
binocular viewing. It would be nice to view through twin Nagler 31's, but
our heads just aren't shaped that way. :-) That's where traditional
binocular designs come in. They manage to squeeze in the wide fields while
still allowing enough interocular adjustment.
Aside from the BT80's, the only binoculars I know of with interchangeable
eyepieces are the Miyauchi 20x100mm and 25x141mm models. These are both in
the "sweet spot" for magnification, aperture, and exit pupil. With the
accessory eyepieces they reach out to 37x and 45x respectively, which is
probably the limit for keeping good collimation and performance. One
Miyauchi owner tried modifying them to use higher powered eyepieces, but it
didn't work very well. Apparently there is a built-in limit to how far you
can push a design that is optimized for widefield views.
> but
> the new model of the 125 mm uses zoom eyepieces to vary magnification
> in the range 25x to 75x, which seems to me rather to sidestep the issue.
I agree, that's a weird design. It seems more suited to terrestrial viewing.
I don't love zooms, but aside from that, this model only has a 1.6 degree
FOV at 25x.
> I think it would be useful to have smaller binoculars with
> interchangeable eyepieces, perhaps with apertures as small as 50 mm.
Yes, I'd like to see that too. Aside from being able to throw a little more
magnification on an object, one of the big advantages of interchangeable
eyepieces on binoculars is that you can put a UHC or OIII filter behind the
eyepiece, where the light rays are more parallel and these filters work
better. It sure beats trying to find a UHC or OIII that will fit the front
objectives on binoculars.
But I doubt we'll see smaller binoculars with interchangeable eyepieces.
There isn't much incentive to pay $300-$400 for a set of accessory
eyepieces, when high quality 50mm and 70mm aperture binoculars are available
for the same price. You might as well just buy another pair of binoculars to
get a different magnification. That's probably the major barrier... the
economics don't work out right for smaller binoculars.
Mike Barrs
Mike Barrs
>
> Mike Barrs wrote:
>
> <<
> The optical designers for Fujinon, Miyauchi, and Nikon are not
> stupid. They design their dedicated astronomy binoculars with
> exit pupils in the 5mm-7mm range. This includes smaller, more
> portable models... not just the big guns. That's because this is
> the range of exit pupils that works the best.
> >>
>
> binoculars, so they want low magnification for that reason --
> large aperture (to collect light) and low magnification (for
> hand-holdability) ==> large exit pupils.
Binoculars in the 20x100mm size have 5mm exit pupils. The even larger
25x141mm and 25x150mm models have 7mm exit pupils. There is no correlation
between size, hand-holdability, and exit pupil. Binoculars can be designed
with large or small exit pupils in both large and small physical packages.
The best way to choose binoculars is to think about the objects you want to
look at, figure out what magnification and field angle is appropriate, and
pick an exit pupil that's appropriate for your eye and the sky conditions.
Once you've figured this out, you can start thinking about whether you want
something hand-holdable or tripod-mounted, because you can get that
combination of magnification and exit pupil in anything from lightweight
$300 binoculars to $14,000 yoke-mounted monsters.
If you think first about hand-holdability, above all other considerations,
and without thinking hard about the optics... then you might end up with
binoculars that don't work very well for astronomy. An extreme case would be
choosing something like 8x30 terrestrial binoculars, but the situation with
IS binoculars comes close. Are dimmer but steadier views better than
brighter but shaky views? Of course! But a tripod would change things in
favor of the larger aperture binoculars. So image stabilization is strictly
a convenience issue. It has nothing to do with desirable exit pupils for
astronomy.
> But with IS low
> magnification is no longer necessary.
You're not interested in seeing extended objects? You don't want to see as
much as possible of the North America or Veil nebula? How about catching a
glimpse of Barnard's Loop, or the next comet that swings through the
neighborhood? Just because we have image stabilization available, it doesn't
mean that 5 degree fields and low magnification are no longer useful in
astronomy. That's putting the cart before the horse.
Don't get me wrong, I like image stabilized binoculars for quick sky
views... as long as there is nothing larger sitting nearby on a mount. ;-)
Mike Barrs
John J. Kasianowicz
any type of instrument (depending on the seeing conditions), your conclusion
really depends on your definition of astronomy.
Very few amateur astronomical observations are published in scientific
journals. I think it's fair to conclude that most astronomical observing by
us is done for pleasure. I'd argue that being able to easily and casually
view the moon, lunar eclipses, occultations, relatively bright doubles, rich
star fields, and the brighter smudges in the night sky with a moderate mag
(and moderate aperture) wide-field binocular can be fun. While the Canon
15x45 IS binoculars may not have been meant for astronomy per se, they do a
remarkable job and I think that they are worth the money (of course, if the
priced dropped a factor of two or more, you won't hear me complain).
I agree that using a scope with a larger aperture is generally preferable,
but very few scopes yield the wide fields of IS binocs. Also, travelling
with most scopes and related accessories (heavy mount, heavy tripod, heavy
battery, heavy TV EPs, gadgets, gizmos, a broked finder that you can't part
with, last year's uneaten chicken salmonella sandwich, etc.) is usually an
ordeal. Binocs have a niche in the observing world and even the non-Keck IS
binoculars have a niche that partially overlaps that of non-IS binocs. It is
neat to pick off a slew of Messier and NGC smudges in short order.
Rob Thacker wrote:
[snip]
Harald Lang
"Mike Barrs" <mba...@NOSPAM.mangonet.com> wrote:
<<
There is no correlation between size, hand-holdability, and exit pupil.
>>
There is a correlation. For fixed aperture, smaller exit pupil
implies higher magnification, hence more difficult to hand hold.
<<
You're not interested in seeing extended objects? You don't want to see
as much as possible of the North America or Veil nebula? How about
catching a glimpse of Barnard's Loop, or the next comet that swings
through the neighborhood? Just because we have image stabilization
available, it doesn't mean that 5 degree fields and low magnification
are no longer useful in astronomy.
>>
You got it backwards. I'm not saying a small exit pupil is the only
useful. I'm objecting to the opposite: someone wrote that an exit pupil
of 3mm was "too small to be useful" for astronomy, or something to that
content. That is generalizing across the board. For much observing, but
not all, a small exit pupil is desirable (for a fixed aperture of
course, meaning high magnification).
Cheers -- Harald
Harald Lang
<<
That is probably part of the reason, but I don't think it's all of it. I
have not seen any astronomical binoculars which have less than a 4mm
exit pupil. Even the 100mm giants, which are certainly not
hand-holdable, still have exit pupils of 4mm or greater. (And those ones
are probably targeted towards comet-hunting.)
>>
OTOH people use their 4" refractors at more than 25x magnification.
I.e., with exit pupils smaller than 4mm.
Cheers -- Harald
Rob Thacker
<la...@deleteme.math.kth.se> wrote:
> OTOH people use their 4" refractors at more than 25x magnification.
>I.e., with exit pupils smaller than 4mm.
Yes, I've said that many times already. Telescopes are great for
high-magnification and small exit-pupil views.
But that's not the purpose of astronomical binoculars. Bright,
comfortable images, and wide true fields of view, is the niche for
binoculars. That's not to say a 3mm exit pupil is useless for
binoculars, but it's not the best for astronomical use.
I.S. is a great invention, but it's not worth the cost in dollars and
lack of aperture, for astronomical use (IMO). The convenience is nice,
but it comes at too high a price.
Rob Thacker
<la...@deleteme.math.kth.se> wrote:
> You got it backwards. I'm not saying a small exit pupil is the only
>useful. I'm objecting to the opposite: someone wrote that an exit pupil
>of 3mm was "too small to be useful" for astronomy, or something to that
>content. That is generalizing across the board.
Lest I be misquoted too much, here is what I wrote (I was that
someone):
-----
"Image-stabilizing binoculars are fine for terrestrial use and
moon-watching. They have small exit pupils, so using them for general
star-gazing is not very good.
"For the huge price premium you pay for the stabilization, you'd be
better off to get a decent pair of large binoculars and a compact
monopod."
-----
I still stand by that. Binoculars are not intended to act as
mini-telescopes; they are for bright, wide-field views. There are
exceptions, of course. But for general binocular astronomy, a large
exit pupil is preferred (especially if it comes via a large aperture).
>For much observing, but
>not all, a small exit pupil is desirable (for a fixed aperture of
>course, meaning high magnification).
Then use a telescope. That's the primary purpose of that instrument.
Harald Lang
rtha...@yahoo.com (Rob Thacker) wrote:
<<
Binoculars are not intended to act as mini-telescopes; they are
for bright, wide-field views. There are exceptions, of course.
But for general binocular astronomy, a large exit pupil is
preferred (especially if it comes via a large aperture).
>>
All I have against this is that you don't express this as a
personal preference but as a general rule. "Binoculars are not
intended to...". "They are for..." A large exit pupil "is
preferred", etc.
I personally much prefer 15x45 to 9x45 for astronomy if the
difficulty of holding them still is not an issue. And it seems to
be the preference of Gary Seronik as well. The larger
magnification shows you more.
Of course it depends on the situation. If you have a
telescope mounted beside you and use binoculars as a compliment,
that's one thing. If instead you use binoculars to view from very
dark sites where you don't haul your 'scope, or if it's your only
observing instrument, it's another situation.
Cheers -- Harald
Sketcher
combination with an eyepiece that provides a 1.25mm exit pupil. If I
use my smaller scope, I tend to use a slightly smaller exit pupil.
The difference is more due to my eyepiece collection than it is to the
differing apertures.
I use lower magnifications (larger exit pupils) when observing objects
that are too large to fit within a higher powered field of view (FOV).
There are some wonderful objects in this category, but the vast
majority of deep sky objects (DSOs) are better with higher
magnifications.
I use even higher magnifications for small objects such as the Saturn
Nebula or to search for 'challenging' details such as the central star
in M57.
Small exit pupils offer the following advantages over larger exit
pupils (all other things being equal):
a) Object image scale is increased. The human eye has much poorer
resolution when used to observe faint objects than it does when used
to observe bright objects. With smaller image scales, more details
will be missed and smaller DSOs will go undetected.
b) The background is darker. This is a direct result of the smaller
true field size -- less sky and fewer stars. One of the benefits here
is that the eye can reach a deeper level of dark adaptation than would
be possible if the FOV were brighter.
Note: The object's total image brightness, as long as it wholly fits
within the FOV, is the same with a small exit pupil as it is with a
large exit pupil -- assuming equal apertures.
rtha...@yahoo.com (Rob Thacker) wrote:
>"Image-stabilizing binoculars are fine for terrestrial use and
>moon-watching. They have small exit pupils, so using them for general
>star-gazing is not very good.
Perhaps some of us are confused as to what you mean by 'general
star-gazing'. If you mean sweeping the sky with the widest possible
field, then you're right. Most of the time I'm interested in using my
binoculars to look at specific objects. For (most) specific objects,
the smaller exit pupils are an advantage.
>"For the huge price premium you pay for the stabilization, you'd be
>better off to get a decent pair of large binoculars and a compact
>monopod."
That's a valid opinion, but different people, with different needs and
different budgets may hold equally valid contrary opinions.
>I still stand by that. Binoculars are not intended to act as
>mini-telescopes; they are for bright, wide-field views. There are
>exceptions, of course. But for general binocular astronomy, a large
>exit pupil is preferred (especially if it comes via a large aperture).
If that's what you believe, then by all means, stick with large exit
pupil binoculars :-)
I really don't care what use the manufacturer had in mind (What do
they know anyway? :-). All that matters to me is the use that I have
in mind.
My past 'obsession' with comet hunting has served me well when it came
to selecting binoculars. I've learned the importance of image size
and image contrast, as well as the importance of a wide field of view.
Those lessons were discovered thru my readings and verified thru
personal experience. I now own and use two very different pair of
binoculars: 8x42 (5.25mm exit pupil) and 20x80 (4mm exit pupil).
For comet hunting, whether I used a 5 inch refractor or a 10 inch
Newtonian, I preferred an exit pupil of about 5mm. A 5mm exit pupil,
IMO, provided the best compromise between field size and image
contrast for that purpose. Smaller exit pupils reached deeper
limiting magnitudes and smaller comets. Larger exit pupils provided
larger true fields of view and reduced sweeping times (but missed
comets that the smaller exit pupils could catch).
For DSO observing, smaller exit pupils are better still. One no
longer has the need for the widest 'practical' FOV that's of so much
importance in comet hunting. Of greater importance is the
magnification and image contrast. 20x80 binoculars will show an
amazing number of DSOs! I once tried to test my limiting magnitude
with the 20x80s. I found a magnitude 'test' chart in a book that went
down to magnitude 13.0. The 20x80s had no difficulty revealing the
13.0 magnitude star, so I tried again under moon light. Still I could
see the 13.0 magnitude star. Perhaps some night I'll re-test the
20x80s using the deeper charts in "Visual Astronomy of the Deep Sky".
My binoculars have served me very well over the years -- revealing M1,
even in bright moonlight, showing Comet Hale-Bopp and M27 in the same
FOV, showing lunar and planetary groupings, revealing lunar surface
detail, and showing countless DSOs and double stars.
I've owned and used 7mm exit pupil binoculars and I've used my
telescopes with 7mm exit pupils. In doing so, IMO, the only thing
gained as a wider true FOV. Sometimes that's important enough to use
a 7mm (or even larger) exit pupil. Most of the time, for me, a 5mm
exit pupil is as large as I want to go -- and that's if I want the
widest 'practical' FOV.
Yes, you can stick with 7mm exit pupil binoculars, and even enjoy
them. By doing so, you would be limiting your astronomical pleasures.
But hey, if that's what you want, or if that's what you believe to be
best -- go for it!
Sketcher
Bill Ferris
exit pupil for deep-sky observing. They're made that way because they're ultra
wide field instruments. If you want a wide field (greater than 3 degrees) you
must accept at least a moderately large exit pupil.
Also, binoculars are often hand-held when used and a low magnification makes it
easier to get a steady hand-held image. Most people have a difficult time
holding binoculars steady enough to get decent image at magnifications beyond
10x. And low magnification equates to a large exit pupil.
Image Stabilization allows binoculars to be hand held and be steady at moderate
powers. A 3-mm exit pupil is moderate power for any aperture. The 15x45 Canon
IS binocs are moderate power instruments. The first time I looked through a
pair I was stunned at the view. They're very nice astronomy binoculars.
If binoculars were made to offer the best exit pupil for most deep-sky
observing, they would offer high magnifications producing a 1-mm to 2-mm exit
pupils. Anyone who doubts that smaller exit pupils are great for deep-sky work
should look at the sketches in Clark's "Visual Astronomy of the Deep Sky" and
Eicher's "Galaxies and the Universe." Then, try it for yourself. Many deep-sky
objects--whether observed through a 60-mm refractor or a 600-mm Dob--will look
best and show more detail at magnifications producing a 1- to 2-mm exit pupil.
Bill Ferris
"Cosmic Voyage: The Online Resource for Amateur Astronomers"
URL: http://members.aol.com/billferris/index.html
Rob Thacker
wrote:
[While I understand the subject has now changed, my comments about
large exit pupils still apply *only* to binoculars for astronomy, from
a moderately dark site.]
>Small exit pupils offer the following advantages over larger exit
>pupils (all other things being equal):
>
>a) Object image scale is increased. The human eye has much poorer
>resolution when used to observe faint objects than it does when used
>to observe bright objects. With smaller image scales, more details
>will be missed and smaller DSOs will go undetected.
Agreed. And if viewing objects is your prime concern, magnification is
as important as aperture. But then, go for a telescope. It's better,
and cheaper, than I.S. binoculars. (You do lose portability, though.)
>b) The background is darker. This is a direct result of the smaller
>true field size -- less sky and fewer stars. One of the benefits here
>is that the eye can reach a deeper level of dark adaptation than would
>be possible if the FOV were brighter.
Sure, if you're viewing in light-polluted skies, then a 7mm exit pupil
won't do you much good. A 3mm pupil is still pretty small, even for
viewing in the 'burbs.
>Note: The object's total image brightness, as long as it wholly fits
>within the FOV, is the same with a small exit pupil as it is with a
>large exit pupil -- assuming equal apertures.
And *never* have I compared binoculars of equal aperture. My whole
argument is that something like 11x80mm binocs are better (for general
stargazing), than 15x45mm binocs.
Sure, if all you can get is 45mm of aperture, then maybe a 3mm exit
pupil is better for viewing objects than a 7mm exit pupil. But I can
buy a hell of a lot more aperture than 45mm, if I don't insist on
automated image-stabilization.
>rtha...@yahoo.com (Rob Thacker) wrote:
>
>>"Image-stabilizing binoculars are fine for terrestrial use and
>>moon-watching. They have small exit pupils, so using them for general
>>star-gazing is not very good.
>
>Perhaps some of us are confused as to what you mean by 'general
>star-gazing'. If you mean sweeping the sky with the widest possible
>field, then you're right.
That's what I mean. Viewing the milky way, viewing clusters like the
Pleiades, dark nebulae, and maybe the occasional good comet.
>Most of the time I'm interested in using my
>binoculars to look at specific objects. For (most) specific objects,
>the smaller exit pupils are an advantage.
Then why not just use a telescope? You'll see far more in objects,
with a scope, even a small scope.
>>"For the huge price premium you pay for the stabilization, you'd be
>>better off to get a decent pair of large binoculars and a compact
>>monopod."
>
>That's a valid opinion, but different people, with different needs and
>different budgets may hold equally valid contrary opinions.
Yes, if money is no object, then get a pair of I.S. 15x45mm binocs, to
compliment a pair with a larger aperture.
>Yes, you can stick with 7mm exit pupil binoculars, and even enjoy
>them. By doing so, you would be limiting your astronomical pleasures.
>But hey, if that's what you want, or if that's what you believe to be
>best -- go for it!
"Limiting my astronomical pleasures"??? Okay, you're getting
sarcastic. You're way off base, too.
For the $1200 that a pair of 15x45mm I.S. binoculars will cost me,
I can buy a quality pair of 7x50mm binocs and 20x80mm giant binocs, a
tripod, and a small telescope!
That hardly sounds like limiting my astonomical pleasure, to me.
Which set-up would you rather have?
Okay, so you already have all that, and still want to waste money on a
pair of 15x45mm binoculars. Fine, instead I'll buy a 12.5" Dob and a
selection of eyepieces. For all but the most unusual needs or
circumstances, my set-up is far more suited to astronomy, than yours.
The point is, that there are many better things you can purchase for
astronomy with $1200, than a pair of 15x45mm binoculars. But if you've
got money to burn, then go for the 15x45mm binocs.
The I.S. binocs do make great daytime binoculars.
John J. Kasianowicz
> And *never* have I compared binoculars of equal aperture. My whole
> argument is that something like 11x80mm binocs are better (for general
> stargazing), than 15x45mm binocs.
If one prefers using binoculars on a tripod.
zgse...@netway.com
They also make great astronomy binoculars -- in fact, they're best in
my opinion. But then you already know that, right Rob? ; -)
Rob Thacker
>rtha...@yahoo.com (Rob Thacker) wrote:
>>
>>The I.S. binocs do make great daytime binoculars.
>
>They also make great astronomy binoculars -- in fact, they're best in
>my opinion. But then you already know that, right Rob? ; -)
Everyone's entitled to an opinion, know matter how wrong it is.
;-)
zgse...@netway.com
mag...@arnprior.com
<la...@deleteme.math.kth.se> wrote:
> I think it's because people want to hand hold their
>binoculars, so they want low magnification for that reason --
>large aperture (to collect light) and low magnification (for
>hand-holdability) ==> large exit pupils. But with IS low
>magnification is no longer necessary.
An interesting thread, this. Your point is a good one, but so obvious
that some people seem to miss it. Good thing there aren't binocular
laws, or I'd be in deep trouble for using my binoculars in unnatural
ways, for things they weren't designed for ;-).
I have found that under a variety of conditions, with a variety of
binoculars, exit pupils down to 3mm can be useful. I have an old pair
of surprisingly good Tasco 7-15X35 zooms. At the lowest power, I could
orient myself in the sky, then once I had found a cluster or galaxy, I
would zoom up. The object would grow in size and detail, as it seemed
to emerge from the background sky. More often than not, I'd settle on
12X power (3mm pupil) as the best overall view. At 15X, detail was
about the same, but the view was too shakey. However, on a tripod, 15X
was better, if a little dim. Depended a lot on how dark the area was,
and how well-adapter my eyes were.
I even tried a pair of Nikon 8X20s. They didn't show a whole lot at
home, but under a really dark sky I was surprised how well they
revealed brighter DSOs. Obviously, portability is their strong suit.
A favourite pair are some 20X60s. I thought some 9X63s would be better
at seeing faint comets and DSOs, but the 20X binocs always showed more
(tripod-mounted of course). My astigmatism made the larger exit pupil
irritating, since it was hard to find best focus on stars. This factor
alone has moved me towards smaller exit pupils.
I do have 10X50s, but they don't get used much--too jittery I suppose.
Then along came the Canon IS. The 10X30s give pleasingly sharp stars,
although the aperture is limited for fainter things like the Veil.
When I get them under very dark skies, I expect they will perform well
(as does everything).
The 'rules' for telescopes apply to binoculars too, I think.
Everything works better in dark skies, more aperture gives brighter
objects, and detail increases with magnification. Given the important
factors of useability, eye relief, focus reach for nearsightedness,
etc., an exit pupil of 3mm is not all that limiting.
Doug Hoy
ell...@my-deja.com
views were impressive. Three months later, the stabalizing mechanism
failed and the binoculars where returned to Canon for repairs. Canon
advised my friend that they found nothing wrong with the binoculars and
returned them after 2 months. However, they must have done something
to them since they performed somewhat better but still were "jerky" and
unuseable. My 7 x 50s were better under these conditions. Reading
this thread, I have marked the arguments vis-a-vis stabalized vs. non
and Canon vs. Fuginon but nothing about problems. Is my friend's
problem unique? And have any of you had to deal with Canon, who in
this instance seem to be sidestepping their responsibilities.
Clear Skies!
Elleray
In article <sQN84.10$4c.2...@news.optonline.net>,
<f...@fff.com> wrote:
> Has anybody tried image stabalizing binoculars? I was not sure if
this would
> work for night sky oberserving although I have been thinking about
getting a
> pair for my use on my boat. Anyway, I saw an ad in Astronomy magazine
for
> Canon's image stabalizing binoculars and the ad was geared for moon
gazing.
>
> Thanks,
>
> Ned
>
>
Sent via Deja.com http://www.deja.com/
Before you buy.
John J. Kasianowicz
failing, the Canon IS mechanism tends to vibrate.
ell...@my-deja.com
the installation of Lithium batteries, and there was no change.
Elleray
Ocean779
>eyepieces on binoculars is that you can put a UHC or OIII filter behind the
>eyepiece,
Fujinon makes a "nebula" filter which fits in the eyepiece of their 7x50 and
10x70 binocs. Anyone tried it?
sean nolan
Mike Barrs
news:20000108050338...@ng-fq1.aol.com...
I haven't used those specific filters, but I've tried taping Lumicon UHC and
OIII filters over the eyepieces of tripod-mounted Fujinon 10x70's. It works,
but it's not quite as good as filters mounted behind the eyepiece, where the
light rays are more parallel and the filter bandpass is tighter. I've
compared the views between taped UHC's over Fujinon 10x70's and filters
behind the eyepiece in a 70mm Pronto. It's a subtle difference, but you can
see it.
This doesn't mean you should avoid those Fujinon fixed eyepiece nebula
filters. It's a great way to get an enhanced view of extended nebulae. If
possible, use nebula filters on the larger aperture 70mm binoculars instead
of the 50mm ones, since they dim the view quite a bit.
Mike Barrs
Attilla Danko
to Canon for repair because of bad stabilization. WHen it returned,
he was still not happy with the small amount of jitter that remained.
He is now looking at getting his money back versus sending it back a
third time.
Email me if you want to make contact with him.
So far, I prefer my mechanicaly gyro-stabilized russian binos, which
seem to do a better job that the 15X45 Canons, even at their best.
Clear, and steady skies.
T. Wesley Erickson
I am delighted with mine; but then again, perhaps I am just too
inexperienced...
The guys at Kitt Peak like them, too.
Wes Erickson
Herb York
news:2iqh4.200$Tn4....@typhoon-la.pbi.net...
Coming soon 18X50 IS (3.7 degree) and 15X50 IS (4.5 degree) Cannon image
stabilizers weather proof.
Herb
http://www.buytelescopes.com online astronomy and camera shop
Anacortes Telescope and Wild Bird
(360)588-9000
>
>
Keith Burnett
<da...@nortel.ca> writes
>So far, I prefer my mechanicaly gyro-stabilized russian binos, which
>seem to do a better job that the 15X45 Canons, even at their best.
I'm interested to know the aperture and magnification of your gyro
binoculars!
How huge is the gyro?
Cheers
--
Keith Burnett
John J. Kasianowicz
Attilla Danko wrote:
[snip
Attilla Danko
the Russian 12x40GS "Peleng" gyro-stabilized binoculars "seem
to do a better job than the 15x45 Canons" (my words).
The details of my opinion are:
- the Peleng's stabilization is much smoother than the
Canon's when you pan around gently.
- the Peleng's stabilzation works at higher jiggling and
panning rates than the Canon. My Pelengs work perfectly
even if I jump up and down while observing.
- when I'm not slewing, the Peleng's image is rock steady.
One of the two Canon's I tried, a very small but noticable
jitter to the image even when I was trying to hold them
still.
- the Pelengs are quite happy in extreem cold (-20 degrees C)
which is quite handy when you live in Canada. (Someone
on the net has warded that the Canon's liquid prisms may
get cloudly at extreem low temperatures.)
- The peleng's optics might be a bit sharper than the Canon's.
I'm not sure, becuase I havent had a chance to A-B compare
them.
- The peleng will run for 10 to 20 hours on a set of 8 AA
batteries.
The downside of the Pelengs, is that they are bigger, heavier and
noiser than the Canons. The Pelengs also look klunky, like 1950's
russian military hardware (which they probably are).
The stabilization lever (mechanica) is a bit harder to hold
down than the button (electrical switch) on the Cannon. The Peleng
also have a smaller aperture and lower magnification. The Peleng
is also much harder to find than the Canon.
However, I got my Peleng, new, for less that half the
prices of the Canon. Given the few complaints I have
heard about the Canon's not-always-perfect image
stabilzation, I think I made a good choice.
Aside from possible quality control issues with the Canon
(residual jitter reported by a few), its clear that
the Canons are fine instruments too.
Clear skies.
da...@globalserve.net
John J. Kasianowicz
Thanks for the information.
In my hands, the Canon 15x45 IS binos can exhibit a very slow pitch (as was
noted by Dennis DiCicco in his review in Sky & Tel). However, I have not
noticed jitter (i.e. a high frequency motion). This could be due to a
variation from unit to unit, or to differences between our eyes. It is
conceivable that your visual system acquires images faster than mine
(although I tend to notice fluorescent lamp or computer monitor flicker more
readily than most people I work with).
Fortunately, I haven't had to use my binos in extreme cold. If they do cloud
up, as you suggest below, that certainly limits their use.
To be picky, I'd like to see the Canon binos have a bit better color
correction. I also wish they provided lens caps for the objectives. During
an observation period when I don't use the binos, I'd like to protect the
objectives w/o having to put the instrument in the "turtle shell" case".
The 15x45 IS binos are fun to use. They are near the limit of what I'd want
to use in the handheld mode for long periods of time. Canon's insistence on
handholding these particular binos is rather clear: they do NOT provide a
tripod mounting socket.
I'll try to check out the Peleng binos. At the price ratio you suggest below
(are you comparing street prices for both), they sound like quite a deal.
Who cares what they look like if they perform like champs? Also, regarding
the noise you mentioned: although I prefer to hear only the sounds of the
critters and the wind at night, eine kleine binomusik can't be all that bad.
Best,
John