HCG 93 WIP

[DaveS]

Work, very much, In Progress.

This is just 6 hours RGB captured on the 7th in 10 mins subs at Bin 2 and Drizzled during stacking. My main computer blew its power supply last night as I was shutting down so I'm on my 2011 eara 17 with AstroArt 8 but no PI. All my calibration frames are on the new computer so I had to put new ones together from the data on my NAS.

Cropp, Gradient Reduction for the sky gradients, DDP, Richardson-Lucy Deconvolution, Selective Colour for the background, Then a light Unsharp Mask and slight Saturation Boost

Saved as a PNG. North is up.

It needs a shed-load of Luminance as it's noisy as hell, the sky was rubbish with thin hazy cloud and a bright Moon.

@wimvb Also captured this in his wide-field of galaxies in Pegasus.

[tomato]

Loving NGC 7549, that’s a proper barred spiral galaxy.

[wimvb]

Very nice already. Adding L will bring out the faint arms/shells of ngc 7550.

[DaveS]

I dunno.

I made a Synthetic Luminance from the entire data set just calibrated with a Master Dark then used it for a Synthetic LRGB. I was able to apply a touch of Unsharp Mask at the end of the processing but not sure if it's made a great deal of difference.

I'm going to be without my main PC for at least a week as it has to go back for investigation, probably a PSU issue, so without PI or the RC AI tools that wouldn't run on this now low spec machine.

[ollypenrice]

Lovely image.

Do you have a slight channel alignment issue? Stars seem to have a blue upper edge and a red lower one. More precisely, it seems to be on the clock face axis running 11.00 - 5.00.

Original:

Red channel moved up by 0.5 pixel and left by 0.2 pixel:

Olly

 

[DaveS]

Thanks Olly.

Actually I do think there's slight misalignment. The alignment in the AstroArt 8 Trichromy routine is very much better than it used to be as it now attends to rotation and differences in scale. but a touch of manual adjustment might be in order now you've pointed it out.

I will go back and have another look.

[wimvb]

2 hours ago, DaveS said:

I made a Synthetic Luminance from the entire data set just calibrated with a Master Dark then used it for a Synthetic LRGB. I was able to apply a touch of Unsharp Mask at the end of the processing but not sure if it's made a great deal of difference.

I did the same. Combined the R, G and B masters in image integration without pixel rejection. I may have darker skies, since I could see the faint parts of the galaxy in the superstretched synthetic L after 7.5 hours of imaging time.

[DaveS]

OK. After some experimentation I found that I had to do an initial RGB combination, then split into individual RGB components then recombine into RGB before AA8 would allow me to make the fine sub-pixel shifts needed.

Ignore the dark star centres, I was more interested in the overall alignment. I think it's better. This is a Synthetic LRGB 

ETA: I've been blinking between the original and realigned LRGB and the improvement isn't marginal, not only the stars have tightened up, the galaxy structure is much better defined, even though the restacked version didn't have Unsharp Mask applied. Thanks @ollypenrice

Edited October 9, 2023 by DaveS

[ollypenrice]

3 hours ago, DaveS said:

OK. After some experimentation I found that I had to do an initial RGB combination, then split into individual RGB components then recombine into RGB before AA8 would allow me to make the fine sub-pixel shifts needed.

Ignore the dark star centres, I was more interested in the overall alignment. I think it's better. This is a Synthetic LRGB 

ETA: I've been blinking between the original and realigned LRGB and the improvement isn't marginal, not only the stars have tightened up, the galaxy structure is much better defined, even though the restacked version didn't have Unsharp Mask applied. Thanks @ollypenrice

Fixed.

Olly