M97 and M108 from last night

[IDM]

Hi,

Last night wasn’t brilliant definitely a bit murky but I set up anyway. Recently I seem to keep trying the same targets so I thought it was time for a change and had a go at the M97 and M108 as they are close together.

I used my SW Equinox ED80 with SVbony UV/IR filter and Zwo ASI 294 MC Pro. I got one hour of data before PHD2 started to complain about losing the guide star, so I called it a night. Subs were 90Second exposures at a gain of 180 (probably a bit high). I briefly processed the images this morning with Darks and flats. I haven’t tried the Svbony filter until today but I do notice blue halos round the brighter stars, might this be due to the filter quality, should I invest in a more expensive filter (it does seem crazy to spend so much on the camera and then scrimp on the filter)?

When I zoom in the image pixelates very quickly. I have read (and tried to understand) some of the threads that discuss over and under sampling and wonder if using smaller pixels size would help in this situation or would smaller pixels simply lead to oversampling? My calculated resolution of my setup is 1.91 arc seconds per pixel. According to PHD2 my mount is tracking with and RMS of about 0.7.

I would be very grateful for any thoughts on the image and the best things I can try to improve my results and thus learn more. I do know I need to improve my image processing skills, but even that is proving quite hard.

Thanks for any feedback

Ian

[Clarkey]

Firstly, for wide field imaging the pixel ratio is fine. Yes with good seeing you might go higher but you won't gain much.

One hour is not a lot of integration time and getting much more will improve the quality. I think most of your pixellation is actually noise. As a rule I never image more than 1 target per night and usually a minimum of 4 hours.

I don't really do much OSC so not really the best person to help on this. I also avoid LP filters. As a rule I would rather collect all the photons I can and remove gradients in processing.