[RCC] M63 comments requested

Hi Ulf,
i did the Galaxy myself in 2018, which was the beginning of the time when i started to go one step further with frame numbers, resulting in one level up in my image quality.

You have good detail in your image, but i think you did slightly too much sharpening. Another point is the stars, i think you could improve it by using a ring cover (is this the right word? Ringblende) for your primary mirror, to have the active footprint circular, and see if there are any reflecting surfaces you can cover.

One thing i'm wondering about is the blue-purple gradient - i think this is not real. A related issue is the color of the Galaxy's outer regions - there is this bar-like structure above the galaxy center. Above and close to this bar, the colors are more black/white. Elsewhere there is this blueish hue.
When you're complaining about stray light, this might be the reason. Also affecting the overall color balance. It might also seep into your filter drawer, if you use one. Restoring the original colors from stray light affected data is very difficult. However, my Sunflower had a yellowish appearance, too, and I think in general i like your colors.


CS Hoschie

Hi, great result for only 2.7 hr. i would work a bit on the background trying to reduce its brightness and desaturate it a little. sharpness is a bit high .. in my opinion. Of course it will help a lot if you put another 3 hr of exposures on top it, if possible.
Clear Skies 

M63 is probably the most difficult object I have imaged so far in my AP "career". With almost 3 hours of integration I still had a poor signal and problems with noise and there was also some disturbing stray light. The color was also somewhat strange when the images was stretched. Among other things I have intentionally reduced a yellow/reddish glow in the central part. Please give me comments on acqusition, processing, color etc.
Link to image:

Hi,

What exactly do you mean by stray light? I'm just asking to make sure that I understand this correctly.

Most noticeable is the blue gradient. Did you run a gradient removal tool? It also seems that you might have stretched the background a bit too much.
Color calibration, background removal should be done on the linear image. With that you should preserve your colors. 

For the acquisition, you should consider reducing the exposure time of your light frames with your f/5 optics and by that capture more subs. By increasing the number of subs you will improve your signal to noise ratio. Also capture a bit more darks. I find 10 a bit low. Usually I take 30 darks, 20 flats and 30 bias. Bias will be captured once and also the darks can be reused if you have lights with the same ISO, exposure and sensor temperature. 

Personally, I try to have the background as a faint gray as a deeply dark background has too much contrast.

Clear skies,
Björn