Modern Telescopes the largest telescope store in India presenting GSO 2" COMA CORRECTOR
 
GSO 2" Photo-Visual Coma Corrector for Newtonian Telescopes
Product Details GSO 2" Coma Corrector for fast Newtonian Telescopes 
 
3-piece modular design (i) Optics in 2" nosepiece with 48mm male filter thread (ii) 2' eyepiece barrel that attaches to optical nosepiece, and (iii) M48 - T2 adapter ring
Design optimized for use at f/4.5 but will work well from f/3 - f/6
Reduce coma and field curvature
Designed for visual and photographic use
Magnification factor of only 1.1x
Fully multicoated optics (4 elements / 2 lens groups) with a clear aperture of 43.9mm / 1.73"
2" nosepiece features smooth barrel and is threaded to accept standard 2" filters
2" eyepiece barrel features brass compression ring and dual large thumbscrews
Back-focus spacing requirement is approx. 70mm from the shoulder of the 2" nosepiece to the image plane. Some customers have reported this to be 72-75mm.
For visual use, connect the 2" eyepiece barrel to the main optical nosepiece (as shown in photo 1 above). Additional spacers might be required at the bottom of your eyepiece (not included) to place the focal plane of the eyepiece at the required back-focus distance.
For photo use, unscrew the 2" eyepiece barrel and attach the included M48-T2 ring to the main optical nosepiece (as shown in photo 3 above). Then attach your D/SLR camera to the male T2 thread via a camera-specific T-ring (not included). Additional spacers will be required (not included) between the corrector and your camera's T ring depending on the camera's CCD chip location to ensure that your CCD plane is set to the correct back-focus distance from the corrector.