TelRad versus Green Laser Pointer

Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.

Thanks

Paul

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"callisto" wrote in message
ups.com...
Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.

Thanks

Paul

I cannot think of any. I use a green laser pointer to point my DOB to
the area I want to look in and it works great. A telrad is a zero mag
finder for pointing your scope to the area of the sky you want to look
in. In my case with a DOB I would need to crane my neck to look thru a
finder like the telrad or the 9x50 finder that is on my scope now.
With the green laser pointer all, I do is hit the button, swing the
scope around and point it where I want to look.

The thing you need to be aware of is if you go to a Star Party, the
use of a laser pointer may be prohibited due to safety reasons as if
you are not careful you can do damage to someones sight with it if you
swing it by and hit them in the eye. Telrads dont have that issue.
Also with a green laser pointer you want to not use it if a plane is
going over in the area you are pointing it to. The better ones will go
a few miles and if a pilot sees it near the plane or it hits the plane
and they see it they will report it to the FAA. Again if you by chance
hit the pilot in the eye, that would be a bad thing too.

That does not mean you should not use a laser pointer as they are by
far the best "Finder" device I have used. I just keep aware of the
skys around me and if a plane is flying by I refrain from using it for
the few minutes it is passing if it is passing anywhere near where I
am looking. I got a green laser from eBay for $25.00 with shipping. It
is a ~5mw laser which is the legal limit before you have to register
it with the Gov. Anything above 5mw has to be registered.

Hope this helps...

Mike...



On Aug 19, 12:08 am, callisto wrote:
Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.

Thanks

Paul

On Aug 18, 9:08 pm, callisto wrote:
Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.

Thanks

Paul


I've used a Telrad for a few years now and only recently have seen
people mounting green lasers to their OTAs for sighting in objects.
Here's my tuppence:

Telrad allows you to adjust the bull's eye as dim as you need for
sighting in objects. When my guide stars are dim I do not desire to
be blinded.

Lasers are helpful to briefly indicate the area to look, to someone
else. They shouldn't be used for more than a few seconds.
Manufacturers warn the heat of prolonged use may kill the laser
diode. (These are not quite industrial grade and should be treated as
such.)

Lasers will only operate off a set of batteries for about 90 minutes
combined time. I still have the same set of penlight cells in my
Telrad after 3 years.

There's always the concern with lasers your beam may intrude upon the
viewing of others and in this day of many astrophotographers you may
wish to check out what your fellows are doing before firing up the
light sabre.


Last star party I was at there were so many lasers waving around I was
getting a bit out of sorts. I feel they have their place as an aide,
not as a crutch.

callisto wrote:
Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.

Thanks

Paul

Hi Paul:

Two basics: the Telrad is a highly personal device: you have to be
within a certain angle behind it to see the circles projected on its
heads-up display. It's very precise, enough so that operators of
scopes with some hefty magnification can make use of them to point the
scopes and find obscure objects.

The laser will project a beam of light into the sky that anyone out to
a pretty large distance (perhaps hundreds of feet under the right
conditions) can see. It terminates at some point in the sky that's a
little different for observers based on distance away from the source.
So it's not as accurate as the Telrad, but it's close enough for
learing constellations, identifying particular stars, etc.

=============
- Dale Gombert (SkySea at aol.com)
122.38W, 47.58N, W. Seattle, WA

On Sat, 18 Aug 2007 21:08:47 -0700, callisto
wrote:

Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.

A Telrad provides a scaled reticle for estimating angle. That scale can
be matched to one on your charts, making star hopping much easier.

A Telrad happily runs all night. A GLP can only be run for a few seconds
(maybe a minute) at a time without losing power, and in some cases
damaging the laser.

A Telrad doesn't interfere with other viewers. In some settings, a GLP
on a telescope may interfere with imagers (something that doesn't happen
when it is handheld).

In general, a GLP is a rather inappropriate device for aiming a
telescope. It is best used as a handheld tool for pointing out an object
to one or more other people.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

callisto wrote:
Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.


using the GLP is invasive in that it ruins the beauty of the night sky
for others. Imagine 4 or 5 people using them at the same time.

And you can forget about astro photography too.

The only place I can see GLPs use as appropriate is in "guided tours" of
the skies for the public.

On Aug 18, 11:08 pm, callisto wrote:
Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.

Thanks

Paul

It's much easier to point accurately with a Telrad than a laser (or a
red dot finder) due to the reticle. That reticle is what makes the
Telrad deadly accurate (assuming you're at a dark enough site to see
many guide stars)...it's easy to place the accurately among the
stars.

Also, if you observe with groups, some folks resent the use of green
lasers.

Thirdly, accidentally point your green laser at one o' them Black
Helicopters, and you'll be hurtin' for certain. ;-)

Unk Rod

Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.


I switched from a Rigel finder (similar in concept to the Telrad) on my
Tele-Vue 76 to a green laser a year or so ago. I like the laser because i
don't have to get down behind the reticle window of the Rigel. I just look
up from the eyepiece, hit the laser button for a second, and re-aim the
scope. I also usually observe alone so don't have to worry about bothering
anyone with the laser light.

..Florian

"Florian" wrote in message
46.128...
Can someone in this group please explain to me the advantages of using
a TelRad as opposed to using a Green Laser Pointer as a finder.


I switched from a Rigel finder (similar in concept to the Telrad) on my
Tele-Vue 76 to a green laser a year or so ago. I like the laser because i
don't have to get down behind the reticle window of the Rigel. I just look
up from the eyepiece, hit the laser button for a second, and re-aim the
scope. I also usually observe alone so don't have to worry about bothering
anyone with the laser light.

.Florian


We use both Rigel Quickfinders (like Telrads, but I like them better) and
green laser pointers, but not usually for the same things. The Quickfinder
lets us point our scope pretty accurately. The brightness of the reticle is
adjustable, and when set to be very faint allows most naked-eye stars to be
seen and used to position. We use the green laser as a pointer - e.g. look
here one third of the way along the line from this star to this star.
Certainly, a green laser can be used to position (we have done this - use
our 20x80 binos as a finder, illuminate with the green laser, and follow the
beam with the scope), and the Quickfinder to point (have someone look
through it to see where the scope is pointed). However, I think that in most
cases the Quickfinder is a better finder, and the laser a better pointer.
That said, I think that using the laser as a finder might make a lot of
sense for someone who has a hard time getting their head/eye behind the
Quickfinder/Telrad. In fact, one of the reasons I like the Quickfinder
better than the Telrad is that it stands up higher on the scope. The other
reason is that it is lighter, and so has less effect on the balance.

Dennis