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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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TelRad versus Green Laser Pointer
nothing but trah tonight
-- There are those who believe that life here, began out there, far across the universe, with tribes of humans, who may have been the forefathers of the Egyptians, or the Toltecs, or the Mayans. Some believe that they may yet be brothers of man, who even now fight to survive, somewhere beyond the heavens. The Lone Sidewalk Astronomer of Rosamond Telescope Buyers FAQ http://home.inreach.com/starlord Sidewalk Astronomy www.sidewalkastronomy.info The Church of Eternity http://home.inreach.com/starlord/church/Eternity.html AD World http://www.adworld.netfirms.com/ "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 |
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TelRad versus Green Laser Pointer
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 |
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TelRad versus Green Laser Pointer
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. |
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TelRad versus Green Laser Pointer
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 |
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TelRad versus Green Laser Pointer
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 |
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TelRad versus Green Laser Pointer
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. |
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TelRad versus Green Laser Pointer
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 |
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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. 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 |
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TelRad versus Green Laser Pointer
"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 |
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