Crops of the above scaled down to approx. half resolution:
The two images are:
Jan 2018: GSO RC6, TS-CCD47 reducer, stock Canon 600D(=T3i) resulting in 1.1arcsec/pix, Celestron AVX, SL50D guide scope w. ZWO ASI 120MM, PHD2, 12x5min, FWHM 5.4...6.5 arcsec
Dez 2018: GSO RC8 carbon, TS-CCD47 reducer, same camera resulting in 0,85arcsec/pix, Skywatcher EQ6-R, ZWO OAG, Lacerta MGEN-II, 34x3min, FWHM 3.4...5.1 arcsec (clouds in some subs)
Processing in PI, though my processing skills might have improved I guess processing has little impact. Both scopes were collimated without any special tools just by creating a concentric look and a final fine tuinig with a bright star.
I expect the current image to become much better as soon as the weather allows to take some clear L with my mono. Here I intentionally compare OSC to OSC to point out the difference of scope, mount and guiding. It is pretty clear that using luminance subs and adding more data yields a better image.
So, I hope it helps someone who is seeking a setup. My conclusions:
- buy a mount in the EQ6-class, don't go for AVX/EQ5
- the small RCs need OAG to deal with the moving rear cell. The RC6 suffer from it a lot, I can't tell how much better the RC8 is as I never tried guiding it with a guidscope and always use OAG
- there is a difference in resolution between the 6'' and 8''version of the same design that is just below / above decency level in my eyes. I have a feeling like the quality of the RC8 is better in general and the better resolution is not only the physical limit but also optical quality of the mirrors.
Edited by the Elf, 06 December 2018 - 03:31 AM.