Howie Glatter Laser Collimator Barlow Attachment
When it comes to lasers and collimation, one of the most trusted names in the business is guru Howie Glatter. His uncompromising quality and dedication to above average products, not only put his name above the rest - but in demand as the finest available on today's market. Usually a manufacturer doesn't take the time to explain to a customer exactly why their product excels over others - or why it performs better - but not Howie. Here's what he has to say about his new Howie Glatter Laser Collimator Barlow Attachment:
"Normally, a telescope takes parallel light rays from a distant star and converges them to a point at the eyepiece focus. Barlowed laser collimation takes advantage of the fact that a telescope will work in reverse. Placing a colllimator into a barlow lens will cause the parallel rays of laser light to diverge, apparently from a point just behind the Barlow lens. The diverging rays projected from the laser-Barlow combination in the focuser are turned into a beam of all-parallel rays when they are reflected from the primary, except for where the center mark on the primary prevents the mirror from reflecting. This reflected beam, containing a superimposed shadow of the collimation target, is projected up to the secondary, and then reflected to the focuser.
If you placed your laser collimator into a conventional barlow lens, you need to attach a paper circle to the end of the barlow as a screen to view the shadow on. The paper circle needs to have a hole in it's center to pass the outgoing beam. The primary tilt is now adjusted to center the target shadow around the hole. The position of the shadow on the screen is effected very little by motion of the illuminating beam. It is almost startling to see the shadow remain stationary as you "bend" the collimator and Barlow around in the focusser, and the fuzzy perimeter of the diverged laser beam moves all over the place.
My Self-Barlowed collimator has a Barlow attachment that screws to the laser aperture for making the primary adjustment. The Barlow attachment is a disc with a small barlow lens mounted in it's center hole, and a flat white front surface as a screen. It makes the Barlow procedure more compact and convenient. The Barlow attachment fits the threaded aperture of any of my collimators, and it can be purchased separately as an additional accessory by those who already have the collimator."