Looking for advice on image processing

I would like to first ask a question: how many subs do you have for each LRGB and how did you do the RGB combination in pix?

Better than anything I ever produced on my own Andy ...

I don't understand the colour management issues. You are imaging with a mono camera in LRGB, so you should have full control over the colours. Just mix your R, G and B channels to your taste. With a bit more colour in the stars and in the galaxies and some deconvolution this will be  a very nice image in my eyes.

Only slight criticism: it's a bit visually unbalanced to my taste. While the galaxy is placed in the golden ratio there is something missing in the upper right part of the image to counterbalance the "left heavy" image. There is just nothing of visual interest in the right half of the image. Did you artificially remove the spikes of your Newtonian in the image? Interestingly some spikes in the stars on the right side could just provide the missing visual weight.

I would crop something like this:


or like this (but losing the small critter on the bottom is a bit of a shame ...):


It would take a bit more time than I invested to figure out the best crop ...

Clear skies
Wolfgang

Thanks for the feedback folks.  I've had a go at re-processing it as follows:

* Not been as heavy-handed with the noise reduction
* Removed the frames from a full-moon night as they had really bad gradients that were affecting my background
* I couldn't undo the collimation issues with the stars, so used a little bit of convolution to smudge out the spikes
* Tried to get some colour back in the stars by not blowing them out
* Pushed the saturation on the galaxy

FWIW:  I just processed RGB this time:  70x90s Red, 44x90s Green, 55x90s Blue (approx 4 1/4 hrs overall integration time).  Gain 139, Offset 10.  ASI1600MM Pro

Well done, Andy.

Hi Andy,
I have a different method in taking pictures.
I usually would do 10 subs for each RGB and then L. I usually take as many L as I could. L contribute to the main details of a picture. I know that do a LRB subs at certain ratio will work, But probably normally people take more L then RGB subs. The subs ratio for LRGB is like 3(or4):1:1:1.

It's really not bad.

Amounts of noise reduction, color balance, and contrast are usually matters of preference, and I've found this to be a challenging target to get exactly right.

The only thing worth mentioning that's equipment/data collection related, would be the triangular stars. This was mentioned above, however in my opinion, this doesn't look like coma, and is likely not astigmatism either. Triangular stars are usually produced from "pinched optics" in which you have uneven pressure on one of the optical surfaces (often the primary mirror). Check the entire scope and make sure nothing is "caught up" or has an opportunity to rub on something; search for this term and you'll find image that have stars just like that…

It's a subtle thing, but to me there's clearly a triagonal nature to your star aberrations. Take the panel just above the middle one, for example:


I'm definitely seeing a three-sided symmetry here, particularly with the edges being straight, and all stars showing the same pattern, which is helpful in identifying the aberration:



Course, if you don't really notice it, then you don't have to go too far into finding solutions!

check out your light frames in chronological order; do they get better, and less triangular, as the night goes on?

Thank you.  I do see it now.  I think part of it is thermal as the stars do improve on individual subs as the night and scope cool down.

Nice! Seems like you're onto something. I'd let it acclimate the necessary amount of time to help with this or take the scope outside before dark.

I always take it out during daylight, however it's been about 20 degrees C plus recently during the early evening and the scope was way over 25 degrees with the direct sunlight, so probably retaining a lot of heat.  In some ways I would be better taking it out at the last minute during late Spring/Summer.