Bill Madewell said:
Guys,
Please forgive my spell. I would like to find the BEST Laser collimater on the Market for my SCT and Dob. Any advise,and where ?
Thanks,
Bill
Bill: It seems that collimating an SCT with a Laser is not really a viable option, about the best one can do is collimate the scope using the standard star technique and then use the collimator to try to repeat that same alignment.
As far as collimating a Newtonian, the Howie Glatter collimators seem to be about the best.
www.collimator.com
Howie Glatter is a one man operation, he has a machine shop in his home and he machines the parts himself. They are simple but precisely machined and are very robust so they stay in collimation. His tolerances on alignment are very tight, 15 arc-seconds which works out to about 1 millimeter at 45 feet.
Howie Glatter lasers also include an aperture stop which provides a precise dot, it looks like a star with diffraction rings. He also has several options, you can buy a barlow attachment to use the "barlowed laser" technique for setting the tilt of the primary as well as a holigraphic attachment.
My experience with Howie Glatter laser collimators has been very good. About 8 years ago, back when collimators were first hitting the marketplace, I bought a 1.25 inch Howie Glatter . It performed flawlessly until I dropped it about 5 feet onto the concrete floor in my garage, this knocked it slightly out of collimation, one of these days I will send it back to be recollimated but it is still accurate enough for my slower scope. At that time I decided it was time to buy a 2 inch Collimator with the barlowed laser option as well as the Holographic option. It arrived collimated and has been serving me well.
Howie also uses a real battery rather than a watch battery so they last a long time, my 1.25 inch is on it's third battery after 8 years, the 2 inch is on it's first.
I think you doing this right. There are quite a few inexpensive collimators on the market place. I have tried to use several of them when helping someone with their collimation. My experience with them is that they are not precisely machined so they are a sloppy fit in the focuser, they have a large irregularly shaped spot and they are likely to arrive out of collimation and even if the user is able to collimate them, they do not stay in collimation. The last one I saw was so out of collimation that the beam completely missed the center dot when the telescope itself was properly aligned. People do learn to collimate these lasers and do stuff like wrap tape around the barrel so they fit better but these are stop gap measures, for collimation of a well made scope, one wants a well made tool...
When I arrive at a dark site and setup a scope, I need a collimator that is precise and I can trust. Among my scopes are a 12.5 inch F/4.06 Truss and a 16 inch F/4.42. Both are capable of giving remarkable images if precisely collimated. The Howie's have been a big help over the last 8 years in getting the good collimation on all my scopes.
I would recommend just contacting Howie via Email and asking him for advice as to which collimator would be the best for you. He makes a 1.25/2 inch model that fits about everything, add the barlowed laser option and you would be nicely set for a long time to come.
That's my two cents.
Jon Isaacs
Attached Image:
