M63

[The Thing]

Image date, time and location:   2022-04-24, Manche, France
Telescope aperture and focal ratio:   TS1506UNC F4, TS-Optics GPU superflat 2" Coma Correktor
Camera and filters used:   QHY294PROC, Svbony 2" UV/IR cut
Processing applied:   PixInsight, Serif Afinity

Had to chop the ends off. Discovered that just moving the scope round the sky changes the collimation! Time to 3d print a new secondary assembly and a primary mirror cell.

[Carole]

Some very nicce detail there. 

Despite it be8ing a coloured camera there seems to be little colour variation just a light blue.  I wonder if this is something you can tinker with. 

What a pain if the collimation is shifting.  Hope you manage to get it sorted.

Carole

[ApophisAstros]

A good capture , slight green hue or is it just my monitor?
Roger

[Roberto]

Very nice galaxy and overall field of view!    Please get rid of the green.  If you use Photoshop, use HLVG (hasta la vista green) or in PixInsight SCNR.

Roberto

[Rick]

just moving the scope round the sky changes the collimation!

Ah, the trade-offs between structural stiffness, optical obstruction, image quality and the effects of gravity...

The image looks pretty good to me.

[Carole]

How long with the subs and ingegration Duncan (for the members images presentation)?

[The Thing]

Thanks all. Too many colour correction tools... I had it just right then clicked Auto Colour in Affinity,

108x120s, Gain 1600, Offset 30, Temp -5C. I don't know why I didn't add those to my initial as I usually do.

[The Thing]

Tweaked for better colour hopefully.

[Rick]

Yep. DEfinitely better.

[Roberto]

That's a good improvement.  How did you rebalance?  I tried downloading your original image and applying SCNR in PixInsight but the image is severely clipped in the background.  SCNR is best applied in the linear stage before stretching and make sure that when you stretch no pixels are clipped.  There is a very high proportion of pixels clipped in the .jpeg version in your first post.

Roberto

[The Thing]

Hi Roberto, I rebalanced using Serif Affinity by re-doing the background removal then manipulating curves and levels for each colour.

I'm working on M101 at the moment and SCNR right after cropping and DBE. I having to clip the background as I'm trying to eliminate what must be reflection doughnuts (whole frame size!). Never got them with my ASI294MC Pro but the QHY294PROC seems prone. I changed UV/IR filter to Astronomic to see if that helped but no joy. The TS GPU coma corrector has only shown reflection problems if the filter draw is right up next to it, but it's at the camera end of the spacing extensions. Any suggestions welcome...

[Roberto]

A dark or bright zone which covers the majority of your frame after calibration most likely means a bad calibration.  You should retake your bias, darks and flats and calibrate again.  I bet your bias or darks are too old and your flats are not calibrating your lights properly.  See this video:  https://www.youtube.com/watch?v=Kkg441UBNpo

[The Thing]

A dark or bright zone which covers the majority of your frame after calibration most likely means a bad calibration.  You should retake your bias, darks and flats and calibrate again.  I bet your bias or darks are too old and your flats are not calibrating your lights properly.  See this video:  https://www.youtube.com/watch?v=Kkg441UBNpo

The flats and dark flats are yesterday's, the darks a month old. I stopped using bias frames and with the QHY I am using the overscan area, not quite sure if I'm using it correctly though as there is precious little info about it anywhere.

[ApophisAstros]

I find its agony of choice with all the ticks and unticks and variation in settings for calibration frames , so maybe one of these could help?
Roger

[Carole]

Any suggestions welcome...

I would suggest it is a post processing error but as l don't use much of the software you are using it is hard to say.  But maybe you have clipped the black point.

I would also increase the colour saturation slightly to colour the stars a bit.

Carole