Another Coma patient - HELP!

[RolandKol]

Hi guys,

was away from astro imaging for a while. Once back, - decided to combat my Coma illness... 
Need advise as simply do not know if I can try something else.

Images attached, are with 1mm spacer.

Imaging train: 130PDS, SW coma corrector (0.9 reducer), T2 extender 11mm , 16.5mm  M42-M48 extender, 1mm Baader Delrin spacer, 20mm ZWO FilterWheel, ZWO ASI 1600MM-pro CCD distance 6.5 = total 57mm and 56mm without 1mm Spacer.

SW Coma Corrector states it needs 55mm, filters in the EFW add up around 1mm into the focal path, - ideal spot should be around 56mm.

56mm and 57mm clearly do not work... (will try 58 tonight...)
how to get to the lower end ? I mean to 55mm, so I could test 55.5-56mm with Delrin spacers.

Are there any 9mm T2 extenders?

Further more...

I am not sure if I have collimated it close enough... I flocked the scope, so had to remove focuser and both mirrors...

Maybe focuser is tilted... Secondary may be slightly off.... kinda.... lots of done... 

 

 

 

raw, 120sec H sub

frame_and_focus_85.fit

 

Edited July 19, 2021 by RolandKol

[RolandKol]

personal note:

Full ZWO setup mentioned above with 1.5mm delring (not 1mm, - mistake above) from CC to Camera body = 51mm overall back focus was 57.5mm