Couple of images from last night

[markse68]

Been a while since I had the imaging rig set up but it was nice and clear and little wind last night so why not- oh there was a big moon of course but it was quite low.

Couple of new to me summer targets:

I started on M57 but it's really too small a target for my scope/camera but the colours came out pretty vivid! Processed RGBHa, 3x500s each filter

Then a couple of hours on the Crescent Nebula which is a much better sized target.  This I processed HaRGB 6x500s per filter with Ha as L as the Ha had the most detail despite the least photon count.

The ring is so bright that I barely had to stretch at all and the star colours are nicer I think. The crescent needed loads of stretching and the star colours have suffered as a result.

Will add a few more hours to the crescent tonight as it looks good again.

Both shot with my 8" f4 on G11, QSI583 with MPCC, Astronomik DeepSky RGB and 6nm Ha, ASI120mm OAG, processed in Siril

Mark

[markse68]

I got a couple more nights on the Crescent Nebula- well actually 4 but 2 of those sessions were wasted because of poor transparency. So this is the result of 8 hrs total. Not sure about the colour balance- it should be red I'd have thought but using the Ha as luminance must be upsetting that. This Time I tried HaRGBHa- not sure if that was a good idea really. Still trying to work out what's best- to pre-stretch the images before stacking or to stack and then stretch. Seems to work much better pre-stretching but I don't see how photometric calibration can be accurate if it's pre-stretched? It's less noisy for sure and I think I prefer it but will play some more with the processing when I have more time. Siril again with a little bit of brightness and contrast in Gimp

Mark