Help - I purchased the Astrotech 115 triplet with the 0.8reducer/flattener. Got delivery of the AT115 first, about 1 1/2 months ago and it seems to work fine for Astrophotography. I used both a Canon 80D, canon 6D, and the ASI183MC cooled camera. I shot at 805mm.
About 2 weeks ago I finally got the Astrotech 0.8reducer/flattener specific for this Telescope. I followed the directions, removed the pieces to get to the threaded focus draw tube and screwed in the reducer/flattener. Several tries indoors and at night with my two DSLRs and the ASI 183 (with adapters to make the required 55mm back focus) results in the focus draw tube going all the way in, to the stop, before focus is reached. This is very consistant with all three cameras.
Am I doing something wrong? and suggestions are appreciated. I have contacted Astronomics and I am waiting to discuss with Mike. This is very frustrating, since the flattener specifically states the 55mm back focus is required, I get that with all my cameras. (spacers for the ATI, and a T-ring for the DSLRs)