How Far Off-Axis Can a Green Laser Be Seen?
Tom Polakis
attend many star parties in Arizona (tonight I will be at one with 60 or
70 scopes), I have to admit I've never seen one in action. I wondered
how far away these things can be seen at all _at a dark site_. One of
s.a.a.'s more sensible posters pointed out that he couldn't see it
unless he was nearly on-axis, which was encouraging. How far away is
on-axis?
If the answer is that you can see the beam from more than, say, 50 feet
away from the person who is shining it skyward, then I'll join the camp
of objectors. I'll even maintain this position if it can be proven that
it can't ruin an astrophoto or dark adaptation. Many experienced
observers I set up with at dark sites spend much of their time
appreciating the beauty of the night sky with their eyes only. If
you're telling me that we now have to contend with unnatural green beams
in our field of vision, that's almost as bad as telling me I have to put
up with the music produced by chain-saw GO-TO motors (hey, I might as
well stir up two pots!).
Tom
--
Tom Polakis
Tempe, AZ
Arizona Sky Pages
http://www.psiaz.com/polakis/
Michael Richmann
Depends on what you mean by "seen". Most lasers have a divergence on
the order of a few milliradians and even taking a cheap laser pointer as
having a divergence as bad as 10 milliradians still means that someone
would need to point it essentially right *at* you to intercept the
actual beam.
OTOH, like any light source, any scattering medium in the atmosphere
(dust, water vapor, etc.) will scatter the beam and make it visible.
But the intensity of this scattered light is usually a small fraction on
the beam. And since pretty much any class II laser has an intensity
less than 5 mW, compare that to a flashlight pumping out any number of
watts and decide how much of a problem this scatter will be on that
basis...
--
Mike
http://www.concentric.net/~richmann/
Tom Polakis
> Depends on what you mean by "seen"...
I am looking for an estimate from somebody who has experienced the green laser
at a star party. I don't think there is any ambiguity to the word "seen." If
I'm sitting 50 feet away from somebody shining the laser only into the sky, do
I see the green spot in the sky on a typical clear night? Thanks.
Chris L Peterson
>I have been reading the two green-laser threads with interest. While I
>attend many star parties in Arizona (tonight I will be at one with 60 or
>70 scopes), I have to admit I've never seen one in action. I wondered
>how far away these things can be seen at all _at a dark site_. One of
>s.a.a.'s more sensible posters pointed out that he couldn't see it
>unless he was nearly on-axis, which was encouraging. How far away is
>on-axis?
I'm sure it depends on your location. Where I am (high altitude, dry, low
particulates), people seem to be able to comfortably see where I am pointing if
they are standing within about 15 feet of me. Farther away than that you lose
the sense that the beam is aimed at a point, and you see it as a dim green line
against the background. You could probably see the beam from 50 feet away, but I
doubt you would notice it without being directed to look for it. I'll try that
experiment tonight.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
Alan French
I have one and it will be used at public star parties to point out
constellations and other interesting naked eye sights. It is not going to
be used as a finder.
I have not used it a lot yet, but it seems you have to be within about 10
feet or so to see it, or at least see it well. At any rate, I have been
somewhat concerned as to how big a group I can use it with before some
people get too far away to see the beam. Over the coming months I will get
a better idea of how far away it can be seen. I'll try to remember to post
my findings here.
There is some dependence on the night. It is not as well seen if the air is
dry, if the site is somewhat light polluted, or if the batteries have been
in use for a while. Also, there is some variation in the power output of
the laser. Generally, they are advertised as being from 3 to 5 mw.
I have seen a couple that seem visible from relatively long distances
"off-axis." I get the impression these are actually more than 5 mw - they
certainly seem far brighter than the one I have, which is supposed to be
just about 5 mw. I wonder if there are some that are actually above 5 mw.
Clear skies, Alan
"Tom Polakis" <pol...@cox.net> wrote in message
news:3CB8727B...@cox.net...
Joe Bergeron
I can't give exact answers. I only know I could only see my neighbor's
beam if he was pointing it more or less directly away from me. I should
be in the presence of a green laser tonight again and will try to
perform some experiments.
In article <3CB8727B...@cox.net>, Tom Polakis <pol...@cox.net>
wrote:
--
Joe Bergeron
Alan French
Actually, the output on mine has been checked and I was told it was in the
upper end of the range. Of course, I have no guarantee of this.
Perhaps my impression that some lasers are considerably brighter than others
is based simply on the variation or different conditions, but I am not sure
there is any guarantee there aren't a few folks carrying lasers that are
over 5mw.
Clear skies, Alan
"John DeGroof" <jdeg...@earthlink.net> wrote in message
news:su6hbuobjdsu2h312...@4ax.com...
>
> First, yours is probably not 5mW, but probably is 3-4mW. I've tested
> many pointers, and have found many "3mW" pointers to be as low as
> 0.6mW! Most of those are 2-3mW. Most of the "5mW" pointers seem to
> be around 3-4mW. Now, there are more powerful pointers out there, but
> they can't be bought legally without a license. There are also some
> that can be disassembled and adjusted for higher output, as much as
> 15-40mW! The danger in that DIY method is you can actually melt the
> frequency doubling crystal in the pointer, and then it's no good - not
> fixable.
> [SNIP]
Michael Richmann
>
> Michael Richmann wrote:
>
> > Depends on what you mean by "seen"...
>
> I am looking for an estimate from somebody who has experienced the green laser
> at a star party. I don't think there is any ambiguity to the word "seen." If
> I'm sitting 50 feet away from somebody shining the laser only into the sky, do
> I see the green spot in the sky on a typical clear night? Thanks.
Asked and answered. If someone shines a flashlight in the sky, do you
usually see a "spot"?
Thad Floryan
Let's push it up to five pots:
3. drunk "astronomers" bumping into everything
4. wailing babies (which really don't belong at a star party)
5. gagging aroma of noxious ethnic foods and/or too much perfume
and/or cologne
Items 3, 4 and 5 are why I don't attend star parties anymore.
Thad Floryan
| Michael Richmann wrote:
|
| > Depends on what you mean by "seen"...
|
| I am looking for an estimate from somebody who has experienced the green
| laser at a star party. I don't think there is any ambiguity to the word
| "seen." If I'm sitting 50 feet away from somebody shining the laser only
| into the sky, do I see the green spot in the sky on a typical clear night?
| Thanks.
In my experience, no, unless the [local] air is dusty/smoky or the relative
humidity is high (neither of which are good conditions for viewing).
None of the green laser pointers produce a beam like those we see in movies
(STAR WARS, etc.); some of the red LED "flashlights" I've seen produce a far
greater [distracting] disturbance due to their brightness.
Thad Floryan
| [...]
| Everyone here who's opposed to the GLP's seems to believe there are 20
| of them on all the time, which isn't the case. I use mine to point
| out objects every now and then, maybe every time I slew to a new
| object, to point out what we're looking at to my friends, or to have
| someone point out the location of an interesting object to me.
|
| On Sat, 13 Apr 2002 18:10:46 GMT, Tom Polakis <pol...@cox.net> wrote:
| >[...]
| >do I see the green spot in the sky on a typical clear night?
|
Heh, several weeks ago during another cloudy night, I beamed my GLP up at
the clouds and, wow, green spot on the underside of the clouds (meaning
they were probably less than one mile overhead). From my office I can
shine the GLP on buildings 1/2 to 1 mile away and see the green spot on
them -- but the beam itself for the most part is simply not visible unless
one is in a very dark location and/or there are atmospheric suspensions
illuminated by the beam.
The beam's visibility (even on-axis) is dependent on local conditions.
Florian
-Florian
http://www.stargazing.com/
Steve Preskitt
<jdeg...@earthlink.net> wrote:
> Yeah, they can be found in places like eBay, where nobody's regulating
> sales of illegal items, or from advertised "adjustable" pointers that
> are pre-adjusted for <5mW so they can be sold legally, then cranked up
> by the consumer to 15mW or more.
It's not actually that the lasers themselves are illegal, just the
display of them in public areas. I don't need a license to buy and use
a 100W YAG rail, but I definitely do need the paperwork if I'm going to
use it in a display accessible to the public. On the other hand, if
the CDRH label says it's a Class III, and it's really a Class II then
there is a problem, but it's still not a licensing issue per se.
Steve
Florian
-Florian
Roland Roberts
John> I have one, and I have seen them used. You can usually see
John> them from 50ft away, or more. Atmospheric conditions play a
John> big role too. Star parties are usually held at lower
John> altitudes, so you're guaranteed to see the beam from a LONG
John> way away. I use it at public star parties all the time, and
John> only once had someone tell me not to use it since they were
John> doing astrophotography. I laughed at him, and wondered why
John> he was attempting astrophotography at a public star party at
John> low altitude.
Glad you're on the west coast. Laughing at me because I'm trying to
do photography in a setting you consider suboptimal is undoubtably a
wonderful way of developing the camaraderie that amateur astronomers
are so well known for.
Having once asked people to please be careful where they were pointed
their red flashlights, I can assure you that you weren't asked simply
because the person was trying to be annoying. Everyone wants the
parties to be fun and asking someone to stop anything _usually_ means
that something _is_ causing a problem for someone.
Since I don't have access to some pristing site above 5000 feet, I
routinely do astrophotography from altitudes as within 100 feet above
sea level. Some of them actually turn out pretty good. If the
weather cooperates, I hope to get a picture of comet Ikeya-Zhang from
about 20 feet above sea level.
roland
--
PGP Key ID: 66 BC 3B CD
Roland B. Roberts, PhD RL Enterprises
rol...@rlenter.com 76-15 113th Street, Apt 3B
rol...@astrofoto.org Forest Hills, NY 11375
zeldman
is very sensitive to drops in battery power. Using NIMH batteries
provides the most stability. And fresh batteries make a huge
difference.
Be Well
Az
Chris L Peterson
wrote:
>You could probably see the beam from 50 feet away, but I
>doubt you would notice it without being directed to look for it. I'll try that
>experiment tonight.
Okay, I tried my laser (rated <5mW, actual value not known, fresh batteries)
tonight under clear, dry conditions. From 50 feet, the beam is pretty visible if
it is directed toward me (within about 20 degrees) or away from me (within about
10 degrees). I could just make out the beam from a perpendicular viewing angle-
it appeared dimmer than the Milky Way, and except for its color I would probably
not see it. I have to consciously look for this beam- just looking around
casually I don't notice it. Basically, if I were using it to point out objects
in the sky, and you were 50 feet away, I don't think you would notice me.
Chris L Peterson
>A retailer isn't allowed to sell >5mW to an individual without a
>license, nor is a non-licensed consumer allowed to purchase (or
>display) anything over 5mW. It's a law that most retailers do follow,
>however it's loosely enforced otherwise.
What law is this? Something that applies to some specific type of seller defined
as a "retailer"? I've bought quite a few lasers over the years, with powers as
high as 10s of watts, from manufacturers and their distributors, and I've never
been asked for any kind of license, nor am I aware of any agency that issues
such licenses (in the U.S.). Agencies such as OSHA do have regulations regarding
the safe use of lasers, but don't require licensing or registration as far as I
know.
Steve Preskitt
<jdeg...@earthlink.net> wrote:
> On Sat, 13 Apr 2002 21:23:33 -0400, Steve Preskitt
> <spre...@nospam.bellsouth.net> wrote:
>
> >It's not actually that the lasers themselves are illegal, just the
> >display of them in public areas.
>
> A retailer isn't allowed to sell >5mW to an individual without a
> license, nor is a non-licensed consumer allowed to purchase (or
> display) anything over 5mW. It's a law that most retailers do follow,
> however it's loosely enforced otherwise.
Could you provide a cite for that? I'm curious, because that means
that practically all of the hundreds of individual job shops that own
laser marking/engraving equipment are working illegally, even though
they're using full CDRH Class I enclosures.
Steve
Thad Floryan
| Okay, I tried my laser (rated <5mW, actual value not known, fresh batteries)
| tonight under clear, dry conditions. From 50 feet, the beam is pretty visible
| if it is directed toward me (within about 20 degrees) or away from me
| (within about 10 degrees). I could just make out the beam from a
| perpendicular viewing angle- it appeared dimmer than the Milky Way, and
| except for its color I would probably not see it. I have to consciously look
| for this beam- just looking around casually I don't notice it. Basically, if
| I were using it to point out objects in the sky, and you were 50 feet away,
| I don't think you would notice me.
Thank you for additionally corroborating the real facts vs. the gut reaction
of those who [obviously] have never seen a green laser pointer in action.
Alan French
You must hang out with a tough crowd. We have a couple of folks who sneak
in a little photography at public star parties. With limited time under the
stars and a limited number of clear nights you have to take advantage of the
time you have.
Clear skies, Alan
"John DeGroof" <jdeg...@earthlink.net> wrote in message
news:t54ibus9d29lfio5m...@4ax.com...
> On 13 Apr 2002 23:47:54 -0400, Roland Roberts <rol...@astrofoto.org>
> wrote:
>
> >do photography in a setting you consider suboptimal
>
> I think anyone attempting photography at a public star party would get
> laughed at regardless!
> [SNIP]
Del Johnson
laser through his refractor in an attempt to polar align the mount. The
wide green beam exiting from the telescope aperture was easily seen from
across the telescope field. I had to come over and tell him that stray
lights were not allowed.
Every RTMC participant is informed that the telescope field is a light
sensitive area as it is crowded with telescopes used for serious viewing and
imaging. He didn't care; he just wanted to play with his laser and argued
at length about having to turn off his laser. This is the sort of thing
that we don't need at public viewing sites.
Del Johnson
"Tom Polakis" <pol...@cox.net> wrote in message
news:3CB8727B...@cox.net...
Chris L Peterson
>There was a guy on the main telescope field at a recent RTMC shining a green
>laser through his refractor in an attempt to polar align the mount. The
>wide green beam exiting from the telescope aperture was easily seen from
>across the telescope field.
How the heck was he doing that, anyway? Did he have some fixture that he used to
shine the laser into an eyepiece to turn the telescope into a collimator? If you
just shine a laser into the end of a refractor, you will get a mildly diverging
beam from the objective that starts at the same diameter as the laser itself
(and will be less visible than the laser by itself). It is actually a bit of a
challenge to get a wide, collimated laser beam out of a telescope. Try it.
Mike Simmons
telescope field and went over to investigate but I don't recall how he
did it. It almost escaped my notice but it was visible. Not until I
got near the scope did I realize what was going on. Before that I
wasn't really sure if there was something there or not and I doubt I
would ever have seen it had it not been a long linear feature.
Mike Simmons
Tom Polakis
> I have been reading the two green-laser threads with interest. While I
> attend many star parties in Arizona (tonight I will be at one with 60 or
> 70 scopes), I have to admit I've never seen one in action. I wondered
> how far away these things can be seen at all _at a dark site_.
At a very large star party yesterday on a transparent and characteristically
parched April night, I was able to watch a green laser pointer in action,
and was quite impressed. I knew exactly where the beam was being pointed,
walked about 15 feet away from the person who was pointing it, and couldn't
see any sign of it. Inside this radius to about 10 feet, it was faintly
visible. Inside 10 feet, it was a bright line pointing to a spot in the
sky.
The laser pointer serves as a great tool for pointing out naked-eye sights
to a small group without annoying the negihbors. Taking it to a new level
of silliness, we began a "laser Messier marathon," attempting to point to
the locations of the Messier objects from memory with the pointer.
So I guess I'm pro-laser, if they are used in responsible hands (and only
after an appropriate waiting period).
Chris L Peterson
>Del's right on this one, Chris...
I didn't mean to suggest that it didn't happen. I'm genuinely curious as to the
setup used to produce a collimated beam from a refractor (it can certainly be
done, of course, it's just not clear how it was done in the field with standard
accessories).
Mike Simmons
maybe someone else will chime in.
Mike Simmons
The Cat Guy
allowed, don't use them, and the cretins who do should be flogged severely.
If it is an astrophotography session where people are taking their shots and
everyone knows this, any moron crass enough to use one should be driven out of
town.
If it is a public star party where the emphasis is on education and trying to
hook the public into getting into our hobby, as long as they are used
responsibly, let the laser light do its pointing. I know that people used to
use fingers, I for one could never see where people were pointing, and
flashlights were harsh. We used to do fine without computers, too...but
without them we would not even be having this discussion. Luddites find
themselves soon left behind in today's world. If it is an observing session
where it is generally agreed that these lasers can be used, why not? If it
weren't for a green laser pointer, we would have never been able to all see
what one guy was seeing...a geosynchronous satellite flashing light off its
panels as it spun. With my reduced night vision, I have a tough time seeing
dim objects even in a dark sky. One of my fellow club members pointed out
where an object was that I was interested in finding and I found it. It has a
place. Its place is certainly not at an astrophotography session, and if
people ask you not to use it you should by all means honor that. To condemn
them wholesale for every possible use is ludicrous. It's like religious
fanatics decrying the Harry Potter books as the Devil's work. These idiots
have obviously never read the books (I am nearly done with the third...most
excellent reading), but yet they denounce them as evil.
Mark H. Rosengarten
isob...@aol.com
-----------------------------------
Jake: Rainbow Bridge
Mina: Gorgeous and loving Tonkinese girl
Milo: Sweet adorable brown and black tabby
Murphy: Orange and white tabby, incredibly sweet
Alan French
Completely off topic, but a minister friend had an interesting comment on
the Harry Potter books. She says they are about a youngster who faces many
difficult choices, and always manages to make the choice that is both
correct and moral.
But, as you say, most critics haven't bothered to read them, and are often
just repeating what some authority figure told them. Very sad indeed.
Clear skies, Alan
"The Cat Guy" <isob...@aol.comdelete> wrote in message
news:20020414160348...@mb-fp.aol.com...
Roland Roberts
John> On 13 Apr 2002 23:47:54 -0400, Roland Roberts <rol...@astrofoto.org>
John> wrote:
>> asking someone to stop anything _usually_ means that something
>> _is_ causing a problem for someone.
John> The individual is irrelevant - majority rules. I always
John> have a crowd asking more questions about the laser than the
John> sky (well, maybe 50/50).
That's pretty harsh. In society at large, it's also generally
untrue. If someone asked you to point your laser pointer somewhere
else and you could, why wouldn't you?
Steve Preskitt
<jdeg...@earthlink.net> wrote:
> On Sun, 14 Apr 2002 03:28:46 -0400, Steve Preskitt
> <spre...@nospam.bellsouth.net> wrote:
>
> >Could you provide a cite for that?
>
> Not off-hand, but I've purchased a fair amount of laser equipment
> online, and they do have that disclaimer on the web sites, although
> they never ask for any proof.
I'll bug our marketing & legal guys and see what they say, although
admittedly it's tough to prove a negative. :-) I'm kinda curious now,
because we ship several hundred Class IV CO2 and YAG lasers every year
ranging from 25W on the low end to about 200W on the high end (and
almost all of them with a .5mW alignment diode :-) ), and while they
try to be really careful on CDRH/OSHA compliance, they might have
missed something.
Steve
Jeff Polston
As I posted on the other thread, I could see a solid green beam from about
40 feet away at the Mid Atlantic Star Party. I tracked the beam to its
"source" to tell them I was imaging in the area. I could see the beam
intermittently from much further away, about 80 feet or so.
Jeff
http://www.mindspring.com/~jeffpo
In article <3CB8727B...@cox.net>, Tom Polakis <pol...@cox.net> writes:
>I have been reading the two green-laser threads with interest. While I
>attend many star parties in Arizona (tonight I will be at one with 60 or
>70 scopes), I have to admit I've never seen one in action. I wondered
>how far away these things can be seen at all _at a dark site_. One of
>s.a.a.'s more sensible posters pointed out that he couldn't see it
>unless he was nearly on-axis, which was encouraging. How far away is
>on-axis?
>
>If the answer is that you can see the beam from more than, say, 50 feet
>away from the person who is shining it skyward, then I'll join the camp
>of objectors. I'll even maintain this position if it can be proven that
>it can't ruin an astrophoto or dark adaptation. Many experienced
>observers I set up with at dark sites spend much of their time
>appreciating the beauty of the night sky with their eyes only. If
>you're telling me that we now have to contend with unnatural green beams
>in our field of vision, that's almost as bad as telling me I have to put
>up with the music produced by chain-saw GO-TO motors (hey, I might as
>well stir up two pots!).
>
Del Johnson
aligns the mount and not the telescope. A polar shaft alignment scope works
much better.
Del Johnson
"Chris L Peterson" <c...@alumni.caltech.edu> wrote in message
news:gmajbu8rfcnhd2nhr...@4ax.com...
Steve Preskitt
<jdeg...@earthlink.net> wrote:
> I did a little digging and found reference to the CDRH and laser
> pointers: "The Center for Devices and Radiological Health (CDRH)
> limits the output power a laser pointer can have to 5mW". I haven't
> found anything in reference to non-pointers.
I wasn't able to get hold of Legal, but I did manage to speak with one
president and one vice-president, and both said that the CDRH and OSHA
rules don't require licensing for lasers of any power, but they do
require a laser safety officer to be appointed for any installation
that will have Class IV lasers in operation, unless those lasers will
be in an enclosure that keeps any radiation in excess of Class I limits
from escaping. In addition, anyone that will be using said lasers must
be signed off on whatever laser safety course is in place. So, the
short version is that anyone can legally buy any power laser that they
want without any kind of license, but unless the beam will be totally
enclosed there are other rules that will need to be followed during
operation that will depend on the output power.
BTW, if you're doing laser displays, you'd *love* our 100W green YAGs.
:-)
Steve
Sr. Software Engineer
baublys/Control Laser Corp.
(who set his tie on fire twice during development of one of our 50W CO2
units...)
Michael Richmann
I'd concur. We've bought a few class IV lasers in the not too distant
past and OSHA compliance was on our end, not the vendor's.
Steve Preskitt
<rich...@concentric.net> wrote:
> I'd concur. We've bought a few class IV lasers in the not too distant
> past and OSHA compliance was on our end, not the vendor's.
Right, if you buy it as a Class IV with no enclosure, you're
responsible, but if the vendor provides an enclosure to bring it to
Class I, they're responsible provided it's not modified.
Steve
William R. Mattil
John DeGroof <jdeg...@earthlink.net> wrote:
>On 13 Apr 2002 23:47:54 -0400, Roland Roberts <rol...@astrofoto.org>
>
>>do photography in a setting you consider suboptimal
>
>laughed at regardless!
This statement is laughable. Plenty of amateurs take advantage of
pristine dark skies to image. Star Party or not. For reference I
suggest that you vist TSP this year and see for yourself.
>>asking someone to stop anything _usually_ means
>>that something _is_ causing a problem for someone.
>
>The individual is irrelevant - majority rules. I always have a crowd
>asking more questions about the laser than the sky (well, maybe
>50/50).
Please tell all of us where you typically observe so that the rest
of us can observe elsewhere. I would hazard a guess that the majority
of us would prefer to associate with others that are less rude.
Besides ..... considering the fact that your *fans* are asking more
questions about the laser than the sky should tell you something, eh ?
>>Since I don't have access to some pristing site above 5000 feet, I
>>routinely do astrophotography from altitudes as within 100 feet
>
>At public star parties?? Sure, I can understand if you don't have a
>great viewing location, but you can certainly pick a better time.
When or where they choose to do AP is really none of your business
and doesn't excuse your actions as referenced in your previous
statement.
Bill
David Knisely
> In article <t54ibus9d29lfio5m...@4ax.com>,
> John DeGroof <jdeg...@earthlink.net> wrote:
> >On 13 Apr 2002 23:47:54 -0400, Roland Roberts <rol...@astrofoto.org>
> >wrote:
> >
> >>do photography in a setting you consider suboptimal
> >
> >I think anyone attempting photography at a public star party would get
> >laughed at regardless!
>
> This statement is laughable. Plenty of amateurs take advantage of
> pristine dark skies to image. Star Party or not. For reference I
> suggest that you vist TSP this year and see for yourself.
Well, here we get into the somewhat muddy question of what constitutes a
"public" star party. For me (and for a lot of other people), it is a
session held by amateur astronomers for the benefit of the general
public who are not amateur astronomers. It is basically an introduction
for non-amateurs to what is up in the sky, showcasing some of the more
prominent objects, rather than just a pure amateur observing session.
In our club, we hold such skyshow sessions at Hyde Memorial Observatory,
and there, not a great deal of astrophotography is done, although
occasionally someone might do an "effects" shot of the party itself with
star trails or a skyline in the background. We do use our "spot-beam"
star pointer to do constellation talks, but lasers haven't been all that
popular (too expensive, not easily visible off-axis over a large enough
area, safety/liability concerns, ect.).
By contrast, our regular monthly club star parties are *not*
generally open to the public (we do have invited guests though), and are
usually held at a more rural location where the skies are darker and
where observing more obscure objects or Astrophotography can be done
with little interference. Observing is somewhat more serious and
independent, although I have seen a flashlight used to point out things
occasionally. I would also not really consider TSP or any of the other
major amateur star parties to be exactly "public", although anyone who
registers can go to them. They are usually targeted mainly to the
amateur astronomer community and perhaps (in the case of our Nebraska
Star Party) members of their family, rather than to the public as a
whole. Astrophotography is indeed done at these pristine dark sky
sites, although at NSP, we also have occasional constellation talks
(with a skypointer in a location away from the main observing fields) in
conjunction with our Beginner's Field School. Perhaps the truly
"public" events should be referred to as "skyshows" rather than star
parties, but the word "public" generally will include just about
anyone. Clear skies to you.
--
David Knisely KA0...@navix.net
Prairie Astronomy Club, Inc. http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/
******************************************************
* Attend the 9th Annual NEBRASKA STAR PARTY *
* August 4-9, 2002 http://www.nebraskastarparty.org *
******************************************************
Del Johnson
lasers at public star parties. An inconsiderate boob like yourself
represents exactly what we fear.
Del Johnson
"John DeGroof" <jdeg...@earthlink.net> wrote in message
news:t54ibus9d29lfio5m...@4ax.com...
>
> I think anyone attempting photography at a public star party would get
> laughed at regardless!
>
> >asking someone to stop anything _usually_ means
> >that something _is_ causing a problem for someone.
>
> The individual is irrelevant - majority rules. I always have a crowd
> asking more questions about the laser than the sky (well, maybe
> 50/50).
>
> >Since I don't have access to some pristing site above 5000 feet, I
> >routinely do astrophotography from altitudes as within 100 feet
>
> At public star parties?? Sure, I can understand if you don't have a
> great viewing location, but you can certainly pick a better time.
>
> --
> John DeGroof, Compressionist
> DVD, DAD, DVD Audio, MPEG, AC3, DTS, PCM, DSD, MLP
karpftj
> On 18 Apr 2002 13:23:53 GMT, w...@rrscfi1.irngtx.tel.gte.com (William
> R. Mattil) wrote:
>
> >majority of us would prefer to associate with others that are less rude.
>
> been asked not to use it. I go scout around first to see if anyone is
> imaging though. Considering the number of people I've observed with,
> and never being asked not to use it, I'd say you seem to be very much
> in the minority.
>
> >Besides ..... considering the fact that your *fans* are asking more
> >questions about the laser than the sky should tell you something, eh ?
>
> so are many other things. If I draw the largest crowd at a star
> party, that should tell YOU something too. Those of us that love
> observing are very much in the minority - to most, it's rather boring.
>
> >When or where they choose to do AP is really none of your business
>
> your business either. If you don't like it, drive further.
>
Do you feel the same way about white-light flashlights? How about
million-candle-power spotlights?
Michael Richmann
Apples and oranges.
--
Mike
http://www.concentric.net/~richmann/
Jan Owen
"I've decided that I like green lasers, and if you don't, that's YOUR
problem. Go somewhere else. I'll go anywhere I damn well please, and your
opinion means nothing to me. All my friends are buying green lasers, too,
so look out; here we come!!! The only thing that matters is whatever WE
want to do. We'll soon outnumber you! Go pound sand!"
Precisely as already predicted.
-------------------------------------------------------------------------
"John DeGroof" <jdeg...@earthlink.net> wrote in message
news:36subusnhrl35vv0o...@4ax.com...
> On Thu, 18 Apr 2002 15:17:34 GMT, "Del Johnson" <dela...@san.rr.com>
> wrote:
>
> >Thanks. I could not have possibly made a better argument against green
> >lasers at public star parties.
>
> Well, better get used to it. 4 of my friends just got green laser
> pointers in the past week. I've run into two other people using them
> at a star party last week - another first, as I've only run into one
> person sometimes. Point is - better get used to it - they're not
> going away. If you don't like it, move to the desert or sell your
> gear. I'm getting rather sick of all the whining about green laser
> pointers in this newsgroup, when in real life there has never been a
> complaint.
Jan Owen
some more, if it provides instant gratification???'
That may be your definition of progress; but it's not mine. I'll get used
to what I care to, not what you would impose upon me. You can either except
it or be bitter about it. I won't lose any sleep. Or you can go somewhere
else.
"John DeGroof" <jdeg...@earthlink.net> wrote in message
news:7favbucv7i5vo1f78...@4ax.com...
> On Fri, 19 Apr 2002 03:10:36 GMT, "Jan Owen" <jano...@cox.net> wrote:
>
> >if you don't, that's YOUR problem.
>
> That's right - it's called PROGRESS. Technology will continue to
> progress. You either accept it or be bitter about it - I won't loose
> any sleep. Man-made planes disrupt the natural view of the stars;
> man-made satellites disrupt the natural view of the stars; green laser
> pointers disrupt the natural veiw of the stars. What's the
> difference? You're used to the planes and satellites... you'll get
> used to green laser pointers too.
Michael Richmann
I'd argue that the damned things ought to stay home on a safety basis
but given the collimated character of the beam and the relatively low
power level (5 mW versus how many Watts for a conventional flashlight,
even with red filter), how do you figure?
Alan French
While I understand the folks that feel the green lasers are detrimental to
our view of the nights sky from an aesthetic view point, I agree that their
actual light output is not a problem (except, perhaps, for
astrophotographers). If folks want to take a purist's approach to enjoying
the night sky, there are other sources of "light pollution" at most amateur
gatherings. There are folks carrying red flashlights that are far brighter
than necessary, and some folks are not very careful about how they use them.
I've had people use a bright red light to look over my equipment while I've
been using it. For some of us old folks, the light level required to view
charts and maps may be an annoyance to younger folks. Then there are the
computer screens, which are often quite bright and can be a big distraction.
You also find people who feel they need to mark some of their equipment with
red leds or, worse, blinking red leds. And of course lots of control
paddles and such have little leds - often quite bright - that show they are
getting power.
Clear skies, Alan
"Michael Richmann" <rich...@concentric.net> wrote in message
news:3CC00125...@concentric.net...
Dave Deming
member of the general public who wishes to view through a telescope is
excepted and encouraged to do so. These events, by their very natue, are
done at sites readily acessable to anyone, public parks, school grounds,
museums, plantariums, not isolated, dark sky sites. Since the main
purpose is to encourage public partcipation,
astro-photography is not really acceptable as it ties up a telescope
that should be there accessible to the public for viewing. Anyone not
willing to accept this should be elsewhere.
Dave
Del Johnson
the one operated by the San Diego Astronomy Association. The site is a
cooperative mixture of several permanent observatories, privately developed
pads and general public areas. I myself have taken several photographs from
the site. It would be next to impossible to "scout around" and verify that
no one is imaging and you would most certainly be asked not to use your
laser in this case.
Del Johnson
"John DeGroof" <jdeg...@earthlink.net> wrote in message
news:sprubu4q1tklvitha...@4ax.com...
>
> I've been using my green laser pointer everywhere I go, and I've never
> been asked not to use it. I go scout around first to see if anyone is
> imaging though. Considering the number of people I've observed with,
> and never being asked not to use it, I'd say you seem to be very much
> in the minority.
>
Darren Drake
had one of these.
Mike Simmons <ecli...@mwoa.org> wrote in message news:<3CB9DC0A...@mwoa.org>...
Bill Meyers
I agree with you.. In any case, I originally suggested the Glatter green
laser finder, or some green laser pointer mounted as a finder, for BACKYARD
OBSERVING IN URBAN AREAS. . Suddenly I am in San Diego at a dark sky site and I
don't know how I got there.
Clear skies,
Bill Meyers
Alan French
Yes you do <g>. This is s.a.a. It's a wonder we haven't heard about
shining a green laser pointer at a music CD to improve the reproduction.
Clear skies, Alan
"Bill Meyers" <st...@auriga.uc.edu> wrote in message
news:3CC0A543...@auriga.uc.edu...
> Alan,
> I agree with you.. In any case, I originally suggested the Glatter
green
> laser finder, or some green laser pointer mounted as a finder, for
BACKYARD
> OBSERVING IN URBAN AREAS. . Suddenly I am in San Diego at a dark sky site
and I
> don't know how I got there.
> [SNIP]
Del Johnson
private pads in addition to the large public areas.
Del Johnson
"John DeGroof" <jdeg...@earthlink.net> wrote in message
news:tda1cust677uo62sl...@4ax.com...
>
> >It would be next to impossible to "scout around" and verify
>
> Everywhere I've been observing has been a tight-packed group, and it's
> rather easy to scout around. One such site is the top of Mt. Pinos
> here in Los Angeles. There's a road leading to the top, and a whole
> lot of trees on the way, so nobody's going to be anywhere else. Even
> if they were, the laser doesn't travel as far as people think, and
> even if someone was, they'd be so far off-axis, they'd never see the
> beam. Another location I visit frequently is the mountains in Santa
> Barabara. From the top, there's a cliff and several other peaks not
> near as high as the peak I'm on, and they're far away. Every star
> party I've been to, whether public or private, has also been a
> relatively tight-packed group, so yeah, it's rather easy to scout
> around.