Item : Green astronomy quality laser pointer
Price: $139
Merchant information: Beam Of Light Technologies. www.z-bolt.com
History - After seeing and playing with a green laser pointer at an AVAC (Antelope Valley Astronomy Club) star party last fall, I decided that this was a “must have” piece of field equipment. It made pointing out locations of objects to a newcomer a snap, as opposed to the normal “See that bright star, no the other bright star, now go east three hand lengths – no, east is over there”. After much hunting, I found a supplier, which was z-bolt. First off, I picked up one of the cheaper versions, and it turned out that it was DOA. Upon calling z-bolt, they said this is rare, since they test every laser before it goes out the door. Lucky me. Upon finding out that I wanted to use it for astronomy, they STRONGLY recommended that I upgrade to a MOD-2. On their recommendation, this was done. The pointer was received in a beautiful box that is a work of art. I think that it is made of rose wood. Enough said – the pointer's home is now my eyepiece case. It also came with a red laser – pen combination, a promotion that has since been discontinued, I believe.
General observations – this pointer will get brighter after about 15 seconds of use. It also seems to dim if the air is warm combined with a few minutes of continuous usage. Not using it for a little while restored it back to working perfectly.
Brightness – As a guess, it is about a magnitude 1 or 2 at 3 feet distance. This dims down to about a 5 at 100 yards. It is possible to see where the pointer is going tonight – with the moon about half full, from a fairly well lit parking lot. A few months ago, when I was under very dark skies, it looked like a star wars light saber going for miles.
Accuracy – The laser is amazingly accurate. You probably could not differentiate each of the stars in the Pleiades, but you can easily differentiate the different stars in the sword or belt of Orion.
Advantages – This pointer is the most amazing teaching tool that I have ever seen. It is bright enough that if a friend is using my Dob, and cannot find an object, I will put the laser at about the right point, and he can site my Telrad and then the telescope itself down the beam.
Disadvantages – If you shine the laser anywhere on the ground, anyone looking at it will loose their night sight. Also, if there are any astro-photographers around, one click with the laser will definitely ruin anything they are trying to do. Another problem is that – for an area about 100 yards in diameter - the laser beam is the highlight of the sky, degrading the experience for others that don't want to have green light across their horizons. Last, this is a VERY powerful laser. It needs to be protected from those who will pick it up and start shining it on other people. (I actually saw this between a 25 year old and a playful 60 year old. Had to tell them to grow up.) I work with a person who has a blank spot in his vision from a friend playing games in High School, and shining the laser into his eye.
http://www.xmission.com/~alanne/LaserPointer.html
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