Current Price: $71.00
Buy It Now Price: $71.00
Bids: 0

Howie Glatter Self-Barlow Attachment for Laser Collimator

Howie Glatter Self-Barlow Attachment for Laser Collimator

Ordering Info
USA Shipping
International Orders
Our eBay Store


  • Used with the Howie Glatter Laser Collimator (sold separately)
  • Barlowed laser collimation is a much more accurate method of collimating Newtonian primary mirrors
  • Provides a highly compact alternative to using a typical Barlow lens – even the "shortie" Barlows
  • The small size of the Self-Barlow attachment reduces the bulkiness and potential misalignment and flexure when using a heavy Barlow lens

Primary mirror collimation is one of the most important goals of the collimation process. Fast focal ratios of modern telescopes introduce errors that exceed the tolerances of standard collimation. Nils Olof Carlin invented the Barlowed laser procedure to allow a much more accurate laser-based method of collimating Newtonian primary mirrors. This is done by inserting a laser collimator into a Barlow lens in the focuser and adding a paper screen to the front of the Barlow. This projects a silhouetted shadow of the primary mirror center mark onto the screen on the Barlow. Centering the shadow on the screen allows the primary mirror to be adjusted with a high degree of accuracy since it is fairly insensitive to any imperfections in focuser misalignment and the fit of the Barlow in the focuser.

Collimation with a regular Barlow lens works, but it forms a long assembly at the focuser that is subject to inherent inaccuracies in the way the focuser aligns the somewhat heavy Barlow lens. Howie Glatter has streamlined the procedure a little with several ingenious devices.

The self-Barlow attachment is a disc with a white screen on the front and a small built-in Barlow lens in the center of the disc. It is then screwed into the Howie Glatter laser collimator aperture and provides a highly compact method for Barlow-collimating.

As with regular Barlowed laser collimation, the shadow is projected onto the screen at the front of the disc at the focuser end so adjusting the mirror at the back of the scope can be difficult in some cases, especially with reflectors having a long focal length.

Note: Occasionally, the product you receive might have a slightly different cosmetic appearance or labeling than what is shown. This can often change from batch to batch according to the whims of the manufacturer. However, you will always receive a brand new, original product as described above.

Description copyright: Agena AstroProducts - Reproduction without permission prohibited.

Back to Top

Filed under: Eyepieces & Accessories