APM 1.25 Inch Coma Corrector ED 2.7x Barlow Lens

APM 1.25 Inch Coma Corrector ED 2.7x Barlow Lens

APM 1.25 Inch Coma Corrector ED 2.7x Barlow Lens is a photo-visual apochromatic Barlow with real ED glass, designed by Gerd Düring in Germany.  This lens is calculated for the correction of Off-Axis Coma in Newtonian telescopes and allows for observation of planets and deep sky objects at the edge from a 1.25″ field of view with the same quality as on axis. Dobsonian users will especially profit from use of this Barlow, as most objects are not exactly centered on axis.

The photographic coma corrected field is perfect for APS-C. Because of its unique quality this lens can also be used with Refractors and Schmidt-Cassegrain telescopes with an image quality no other Barlow equal to its price will reach.

Optimized for parabolic mirrors with f-ratio f/4 and featuring Chinese ED glass FK61 (similar to Ohara FPL51), the lenses are soft cemented and applied on both sides with a broadband multi-coating with over 99% transmission for wavelength from 400 nm to 700 nm.

The optimal back focus is 105mm from center of the last lens. The focal length of the Barlow is – 62.9mm, the clear aperture 22mm. Offering a 22mm aperture in secondary focus and a 100% illuminated photo-visual field for APS-C when used with 105mm back focus.

The 2-part adapter is visual with the optimal back focus of 105mm with the centering brass clamp. This deluxe adapter has a length of 55mm and can be unscrewed, with a photographic T2 thread (M42 x 0.75 mm), for use with a DSLR with T2 adapter ring.

First results with the ED-Barlow have been amazing!