-Amenophis-

Hello, So, Please find my test image. I tried to adjust the collimation as best as possible with the option "real time" and then I took a break of 20s BIN1x1. Technical specifications include: - Newton 254/1000 - Paramount MyT - ASA 0.73x corrector - Moravian G2-4000 - Image scale: 2,032 - Focal: 751.12 - RA 15 04 05.392 - DEC +26 48 25.53 The goal for the moment is to find the correct distance of the backfocus for the corrector. The TILT will be the next step. For Downloading Image .fit : http://Link to Download image .fit This is the field

Thank you How do you check that? (the good distance for Backfocus) Do you use software like CCDInspector to see if the distance is good? (see coma)

thank you mark ! Just to be sure : Backfocus CCD moravian and filter wheel : 33,5mm Connected rings : 15mm AOG : 15 mm Filter astrodon : - 1mm So : (33,5 + 15 + 15 - 1) = 62,5 mm In conclusion, add 3mm extension rings to obtain 65,5mm

Sorry, but my focal length is 1000mm (Newtonian 254/1000 FD4). So i calculate 65,5mm is that correct ? Thank you

Thank you very much for your help

Edit : more information about telescope 254mm diameter Focal lenght : 766.94mm with ASA reducteur (astrometry) FD 3

Hello, I own the ASA 2" reducer 0.73 and I can not find the right measure for the BackFocus. Here is my equipment: Newton telescope : focal 766.94mm I tried with the table in the documentation of the correction but I can not be the measure precisely. Thank you in advance for your help. Have a good day