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Laser pointer as a finder
Laser pointer as a finder
The original mount had two screws in the front and two in the rear. The screws in the rear were perpendicular to the front screws. Making adjustments was a bit difficult as the pointer would slip out from under the screws. I added two extra screws to form a three point adjustment. Screws "A" and "A1" are original and screws "B" are new. Note how screw "A1" is used to actuate the momentary switch on the laser pointer.
Alignment:
Alignment:
Laser pointers and ambient temperature:
Laser pointers and ambient temperature:
Lasers pointers work wonderfully at temperatures above about 60 degrees F. Unfortunately, their performance rapidly drops off below that till they won't work at all. In these cases, you'll need some kind of heater for low temperature observing. There are several heater designs out there that will solve this problem. A google search will turn up several. If you use a Dew Buster, one of the 12v outputs can be used with the appropriately designed heater. Otherwise, just keep the pointer in your chest pocket, nice and warm till you need it next.
More information on heating your laser pointer can be found toward the bottom of this page: Cold weather observing extenders
By the way, as of January 2018 Orion has a nice package deal for a 5mw laser and holder. A quick search shows tons on the internet. Things have come a long way since I originally wrote this page back in 2010.
A note is in order: The beam of most pointers is NOT usually axially aligned with the body of the pointer. It may take some radical adjustment of the alignment screws to get the end of the beam centered in the view. Once done though, you'll only need to tweak alignment for each observing session. I typically loosen only one screw front and back to remove and install the pointer. If you plan on making your own laser holder, keep this fact in mind and allow what may seem like excessive adjustment range in your holder.
To align the laser and scope, you don't need to be looking at a target star. Just point the scope up in a comfortable viewing position for the eyepiece. Here's the trick regarding first time alignment accuracy:
Make sure the Laser pointer is LOOSLY mounted in the holder. In fact, you want it loose enough that you can make wide sweeps with the laser while it's in the holder. This means significantly backing off the front alignment screws (The rear set of screws just hold the pointer centered in the back). Now, look through your lowest power, widest FOV eyepiece and then move the pointer around until you see the beam streaking out into space through the eyepiece. It should come into the field of view from the periphery. This is important: As shown in the image at right, for accurate alignment, the beam should terminate in the center of the FOV not just bisect it. Firm up the alignment screws and then refine the alignment as you would a regular finder.
At this point, the laser is well aligned to your scope. A few tries and you'll soon be putting the end of the laser on your target and it WILL be visible in the eyepiece!
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