Problem: elongated stars across entire field. noticeable more when shoot M8 pointing west than east. This problem has only reared it's ugly head over the past 2 months since i rotated my Moonlite focuser shooting M8 and M20.
Tests 3 weeks ago:
1. Recallibrated guide star when pointing West
2. Re balanced scope
3. Added weight to east when pointing west to counter possible backlash
4. Removed and re fitted Hotech field flattener with rubber expansion ring. Camera attached tight.
5.Checked for any looseness or drawtube slop on anything on my Moonlite focuser
Test on Saturday
1. re polar aligned, can hold a star centre in illuminted reticle for 12-15min any position in sky
2. removed and re fitted field flattener.
Result: elongation in centre and now rotating oval stars at corner edges. please see images attached. Elongation worse when i point the sope west than east.
Could this possibly be flexure or miss aligning optical train? I am only using a modified finderscope as a guider and everything appears tight.
set up
scope: ed120
Guide scope: small modded finder scope
Focuser: Moonlight high res
Field Flattener" Hotech 2 inch with expandable rubber rings
Camera: Canon DSLR
