Try at M42

[Stian]

Hi,

Just wanted to share my 3rd attempt at M42. Using a Nexstar 6SE w/Wedge/Focal Reducer/Canon 100D.

47x45s@ISO800

Stacked with DSS

Tried to adjust some levels / curves in PS.

 

Inputs for improvement are very welcome. (Both on scope / mount / camera settings + PS) (I am trying to setup PHD2 guiding, but sofar feedback from PHD2 is that RA & DEC vary to much)

[ollypenrice]

Firstly you have a nice Trapezium region and M41. Good stuff!

In terms of improving, the most striking thing is that star shapes are reasonable in the top centre of the image and become progressively worse towards the bottom, where they really do need sorting out. It isn't obvious, to me at least, what's behind this. Collimation, polar alignment, chip tilt, spacing from reducer, could all be playing a part here, but not tracking/guiding. Errors in tracking/guiding go in one direction. That isn't the issue here. The way the stars make cometary tails at different angles around the chip clearly says that the issue is optical.

Olly

[Stian]

Hi Olly,

Thanks, posting one of the original lights which has not been cropped. Here You also see some strange reflections or similar in the bottom.

Also posted another pic here where it is clearly something wrong:

 

Will do some tests related to collimation tonight with / without the focal reducer attached.