Eyepieces: Orion Lanthanum Superwide vs Televue Radian?
Roland Roberts
above *sound* pretty good to me. I wear eyeglasses and have
significant astigmatism, so the 20mm eye-relief is a must (okay, I
might be able to get by with a little less, but 10-15mm is too
little). The prices are about the same as well. The Orion eyepieces
are nominally 65-degree AFOV and the Radians 60-degree.
Has anybody had the opportunity to use both and have any opinion on
the relative merits of the two?
roland
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Michael A. Covington
excellent, and I think they are generally considered the better of the two.
The Lanthanum Superwide does offer a focal length that Radian doesn't (I
think it's 22 mm).
Space Traveler
wrote:
>I'm working up to the point of buying some eyepieces and both of the
>above *sound* pretty good to me. I wear eyeglasses and have
>significant astigmatism, so the 20mm eye-relief is a must (okay, I
>might be able to get by with a little less, but 10-15mm is too
>little). The prices are about the same as well. The Orion eyepieces
>are nominally 65-degree AFOV and the Radians 60-degree.
>
>Has anybody had the opportunity to use both and have any opinion on
>the relative merits of the two?
>
>roland
Roland:
Have you given the Pentax XL's any consideration? You may look at
them too?
Sorry, I know its no help for someone to bring something to give you
one more choice but ...
The instajust on the Radians sucks IMO. The Pentax is a far better EP
anyway, and I love the screw down feature! Eye relief is 20mm in all
and the AFOV is 65 in all but one.
Check out this review site:
http://www.excelsis.com/vote/astro/index.html
Space Traveler
Jeff Morgan
<rol...@rlenter.com> wrote:
> I'm working up to the point of buying some eyepieces and both of the
> above *sound* pretty good to me. I wear eyeglasses and have
> significant astigmatism, so the 20mm eye-relief is a must (okay, I
> might be able to get by with a little less, but 10-15mm is too
> little). The prices are about the same as well. The Orion eyepieces
> are nominally 65-degree AFOV and the Radians 60-degree.
>
> Has anybody had the opportunity to use both and have any opinion on
> the relative merits of the two?
>
> roland
Roland,
I have used the Radians and the Vixen Lanthanam. The Orion may just be
the private label version of this, I'm not sure. I was not overwhelmed
by the Vixen, thought it was inferior to Televue in terms of sharpness,
especially near the edge (at f/5). The Radians are fabulous across the
field.
Radians also have the Instajust which some people really like, although
I really don't care for it.
In terms of field comparison, I generally use 68 degree Panoptics. The
60 degree Radian is of course less, but not dramatically so. It does
appear to be dramatically more than 50 degree Plossls which I feel give
a detached, tunnel-vision appearance. Personally, I wouldn't worry about
60 degree fields being too small.
--
Jeff Morgan
email: substitute mindspring for nospam
Saul Sodos Chicago
Danny & Donna
Don't forget the new 2" 70 degree 42mm! I'm "eyeballing" it as a way to get
more field in my f/10 10".
Danny Cobb
Bill Becker
Roland is asking about the Vixen Lanthanum super wides...I've only read
good things about them. I think Joe O'Neil was one who said they were
quite good.
Re the regular Lanthanums, a 20mm came with my Vixen refractor and the
images are real dim compared to a 22mm Pan and 18mm Kellner and Orthos.
Best regards,
Bill
Roland Roberts
Danny> Don't forget the new 2" 70 degree 42mm! I'm "eyeballing"
Danny> it as a way to get more field in my f/10 10".
I should have mentioned I'm only looking at 1-1/4" eyepieces. I do
wish they had a 30mm....
Roland Roberts
Saul> Pentax XLs are better than either of the above.
Well, thanks for the great tip. Any hot stocks you want me to know
about while you're at it?
Seriously, have you used either of the other two? What were your
impressions? If you have anything constructive, I'm all ears. If
not, well, that's what killfiles are for....
Bret Akers
Pentax XL's (which also have 20mm eye relief and a 65 degree FOV) through
the same scope. I wasn't able to compare the same focal lengths across all
of the brands, but I was left with the impression that the Pentax XL gave a
slightly better view than the Radian, which gave a slightly better view than
the Lanthanum Superwide. This was during a night of exceptional seeing.
During average seeing, I'm not sure if the differences would have been as
noticable.
In any case, I'd buy the Pentax XL first. If you need a focal length that
Pentax doesn't offer, such as 3mm or 4mm for planetary viewing, I'd get a
Radian. Since the Lanthanum Superwides are effectively the same price as the
Radians and the Pentax XL's, I would generally stay away from them.
"Roland Roberts" <rol...@rlenter.com> wrote in message
news:m2d7b1z...@tycho.rlent.pnet...
Roland Roberts
Bret> I've had the opportunity to look through Radians, Lanthanum
Bret> Superwides, and Pentax XL's (which also have 20mm eye relief
Bret> and a 65 degree FOV) through the same scope.
[...]
Thanks, this is the sort of comparison I was interested in. I was
disappointed in finding that the Pentax XL 28mm has a 55-degree AFOV
instead of a 65-degree AFOV. I wonder why they did that?
Bret Akers
FOV and I don't know why they didn't. However, if you're looking for an
eyepiece in this range, you might want to look at the 27mm Panoptic, the
35mm Panoptic, or the 31mm Naglar. All of these eyepieces have at least 19mm
of eye relief and have a 2" barrel to put up a wide field.
> <snip>
Joseph O'Neil
wrote:
>Has anybody had the opportunity to use both and have any opinion on
>the relative merits of the two?
Hi;
About ayear ago I took both an 8mm Radian and an 8mm Radian
out ot a gorup of guys observing,a nd we passed them all around. I
ahve also tried out the Pentax SMC line too, and those three put
together are my three favourite eyepeices out there. Anyhow, back to
the Vixen SW and the Radain, here goes....
For planetary use, overall contrast and colour, the Radian is
the winner. Not by a huge margin, but the winner.
For ergonomic comfort, that is, an eyepeice that you can stare
at for hours and never feel eye strain, the Vixen is the winner.
In short, what I now see around here, is that many peopel
actually use both. I notice how it seems to work is that for high
power work, especially planetary work, guys are buying Radians, mostly
in the 3mm ot 10mm range.
However, these same guys are also buying the Vixen SW in the
17mm range and higher. For deep space use, the vixen seems to be
preferrred, partly due to it's 65 degree FOV vs the 60 degree FOV of
the Radian.
So without knowing exaclty what you are looking for, think of
the Vixen as an excellent deep sky eyepeice, and the Radian the one of
the best planetary eyepeices out there.
Now, that all being said, if you ever have geh chance to come
accross the Pentax SCM-XL line, they are very nice too, and give botht
he Radian and the Vixen SW a serious run for the moeny.
As for myself, what do I personally use? My favourite three
eyepeices are a Vixen SW, a TV Panoptic and a Pentax SMC. It's like
have a Ferrari, a Porsche and a Jaguar all parked the the same garage,
they are all nice to use.
:)
joe
Dan Mosher
(22,17,13), the Radians (14,12,10,8), abd the Pentax XLs (21,14,10.5) on
a variety of scopes (12.5 inch f5 DOB, C-8, C-5, ETX, and ST80). I have
done some direct comparisons. All of these are fine eyepieces.
I started with the Superwides - and I liked them a lot. Sharp, good
contrast, comfortable to use, etc. The I added some Radians and finally
some Pentax XLs. I have found myself moving more to the Pentax XLs and
Radians.
Why? The Superwides are great eyepieces but I think the Radians show a
bit more more contrast and detail on the planets. The radians are
physically smaller and lighter than the Superwides. The Superwides have
8 elements the Radians have 6. It's basically a trade off - you give up
some field of view for a little better planetary planetary performance
and a smaller size.
The other factor is a practical one that ended up being important to
me. The Superwides are not close to being parfocal with most other
eyepieces (although they are nearly parfocal with each other). I found
the amount of refocusing necessary when switching between Superwides and
Radians and Pentax XLs to be annoying. Radians and Pentax XLs are much
closer to being parfocal with each other than with the Superwides. So
I have been gradually moving away from the Superwides (which I liked a
lot) to Pentax XLs and Radians.
Pentax XLs are fine eyepieces. Very comfortable to use.
Bottom line for me. If I was interested only in deep space, didn't mind
the size, and didn't mind using only one type of eyepiece, I may have
stayed with the Superwides. For practical reasons, I find the Pentax
XLs and Radians to suit my needs better. I have had a hard time getting
rid of the Superwides (because I have some fond memories of some of the
things I have seen through them) and I'm still hanging onto the 17mm
(partly because of fond memories and partly because it fits into a small
gap in the Pentax XL line).
One other comment. Under slighly light-polluted skies, the 22 Superwide
seems to show slightly darker skies than the 21 Pentax (perhaps the
difference between 8 elements and 6 elements).
My 2 cents worth
Dan
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>
> * Newsgroups: sci.astro.amateur
> * From: Roland Roberts <rol...@rlenter.com>
> * Subject: Eyepieces: Orion Lanthanum Superwide vs Televue Radian?
> * Date: 28 Mar 2001 17:31:23 -0500
> * Organization: PANIX Public Access Internet and UNIX, NYC
>
> ------------------------------------------------------------------------
> ------------------------------------------------------------------------
> Mailgate Follow-Ups:
> Re: Eyepieces: Orion Lanthanum Superwide, Michael A. Covington
> Re: Eyepieces: Orion Lanthanum Superwide, Space Traveler
> Re: Eyepieces: Orion Lanthanum Superwide, Jeff Morgan
> Re: Eyepieces: Orion Lanthanum Superwide, Saul Sodos Chicago
> Re: Eyepieces: Orion Lanthanum Superwide, Bret Akers
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Jeff Morgan
<rol...@rlenter.com> wrote:
> Seriously, have you used either of the other two? What were your
> impressions? If you have anything constructive, I'm all ears. If
> not, well, that's what killfiles are for....
You could buy one of each type in similar focal lengths from a dealer
with easy return policies.
Or, you could just sell the brand(s) you didn't like on Astromart. They
all hold their value fairly well, so it wouldn't cost you a lot to erase
all doubts before you invest in the whole collection.
JDBraddy
a 6mm Radian, and most of my observing buddies have the radians. I never
could tell any diffrence in sharpness or contrast between the two brands,
both seem about as good as it gets to me. I've used them in a variety of
scopes from 80mm refractors to SCT's and 20" dobs. Just when I think one is
clearer or sharper in a particular scope, I try to verify it in another
scope, and come up with a conflicting conclusion. It would definately take a
more skilled observer than I to detect a clear diffrence. I do tend to
prefer the Superwides because because of some astetic features. They're all
about the same size and weight, so no balancing problems between eyepieces.
I hate the insta-adjust on the Radians, the LV Superwides are slightly
heavier, but have a much more solid feel, a lot of checkered rubber on the
outside makes them easy to hold on to, they fit either a 1.25 or 2" focuser
without an adapter, so no matter how I have my focuser set, or which scopes
I swich them between, they fit without a hitch. They also have a wider field
than the Radians. Never had the opportunity to try the Pentax XL's, but sure
would like to. Anybody wants to loan me a couple? Have heard nothing but
good things about them. A few on this board have had bad experiences with
the regualr Vixen Lanthanums, So the LV Superwides have never really been
able to overcome that bad-wrap, and of course there are those who are name
brand fanatics, and will never admit anything could be as good as a
comparable Televue, or Pentax, or other big name product, no matter what!
This suits me just fine cause it keeps those comparable products available,
and fairly cheep on astromart, from those who just have to try a Radian or
Pentax for themselves, just to see what everyones talking about, and sell
their LVSW's to finance the venture. In terms of investment, the Radians and
Pentaxes will both hold their resale value better than the LVSW. You really
can't go wrong with any of these eyepieces, they are all excellent!
--
Posted from [24.93.35.223]
Roland Roberts
Bret> Pentax would need to put a 2" barrel on the 28mm eyepiece to
Bret> get a 65 degree FOV
[...]
Really? I know nothing about eyepiece design, so I don't know where
the limits are. What's the largets 1-1/4" eyepiece with a 65-degree
AFOV?
Roland Roberts
Jeff> You could buy one of each type in similar focal lengths from
Jeff> a dealer with easy return policies.
Jeff> Or, you could just sell the brand(s) you didn't like on
Jeff> Astromart. They all hold their value fairly well, so it
Jeff> wouldn't cost you a lot to erase all doubts before you
Jeff> invest in the whole collection.
That's a very sensible approach although I was planning on acquiring a
complete set of the course of the next year to avoid a big cash
outlay. To buy three at once means convincing my wife to let me
deplete the bank account all at once. One of the books I was reading
(StarWare 2?) mentioned that I should double whatever I plan to spend
on my hobby as my expenses where likely to be matched by my wife's
expenses on her hobbies :-)
Michael A. Covington
> >>>>> "Bret" == Bret Akers <ak...@needtoscream.com> writes:
>
> Bret> Pentax would need to put a 2" barrel on the 28mm eyepiece to
> Bret> get a 65 degree FOV
> [...]
>
> Really? I know nothing about eyepiece design, so I don't know where
> the limits are. What's the largets 1-1/4" eyepiece with a 65-degree
> AFOV?
About 24 mm.
Assuming no distortion, it's equivalent to the following question: What's
the height of a triangle with a 65-degree angle at the top, and the base
about 31 mm (largest possible to fit in a 1.25-inch tube)?
Focal length = (31mm / 2) / (tan (65/2))
where 31mm is the diameter of the largest lens you can have inside a
1.25-inch tube, and 65 degrees is the apparent field.
So...
Roland Roberts
Michael> "Roland Roberts" <rol...@rlenter.com> wrote in message
Michael> news:m2lmpoe...@tycho.rlent.pnet...
>> [...]
>> What's the largets 1-1/4" eyepiece with a 65-degree AFOV?
Michael> About 24 mm.
Michael> Assuming no distortion, it's equivalent to the following
Michael> question: [...]
Thanks! That help me to set my expectations appropriately.
Bret Akers
> > Bret> get a 65 degree FOV
> > [...]
> >
> > Really? I know nothing about eyepiece design, so I don't know where
> > the limits are. What's the largets 1-1/4" eyepiece with a 65-degree
> > AFOV?
>
> About 24 mm.
>
> Assuming no distortion, it's equivalent to the following question: What's
> the height of a triangle with a 65-degree angle at the top, and the base
> about 31 mm (largest possible to fit in a 1.25-inch tube)?
>
> Focal length = (31mm / 2) / (tan (65/2))
>
> where 31mm is the diameter of the largest lens you can have inside a
> 1.25-inch tube, and 65 degrees is the apparent field.
>
> So...
>
Exactly. However, since the eyepiece needs to have some wall thickness, the
maximum practical field stop is about 27 ~ 28 mm. So the longest available
eyepieces with a roughly 65 degree field are the Pentax XL 21mm (65 deg
field), the Meade 24.5 superwide (63 deg field), the 22mm Panoptic (68 deg
field), the 22mm Lanthanum Superwide (65 deg field), etc.
You can figure out the true field of view for your eyepiece/scope combo by
using the following formula:
True field of view (degrees) = (eyepiece field stop diameter / telescope
focal length) x 57.3
Fred Sensabaugh
the Radians. I did not like this feature either so I took the instajust
feature apart and tightened the spring and reset the adjustment to the best
setting for me. I now love the eyepieces. The instructions that come with
the eyepieces state that you should not take the instajust feature apart but
it is really nothing to it.
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