Two version of M81

[old_eyes]

These were captured on Pier 1 @Roboscopes (ADM 250 F6.8 Dall-Kirkham 1678mm FL with ASI1600MM Pro Camera)

Same data 2 processed versions

RGB only

 

LRGB

 

In many ways I prefer the RGB. I seem to struggle getting much benefit from adding the Luminance. Could be crap processing of course!

What do you think?

[pipnina]

What is the total integration for each channel and luminance? IMO the benefit of adding luminance is that in one hour, you are capturing the equivalent of THREE hours of RGB in terms of signal to noise. This means getting clean brightness data is way faster and you can pick out faint things easier and darker structure will look cleaner.

However there is a limit to this. And in my so far limited experience with a mono cam, I think adding luminance is not worth it until R G and B have at least 2 hours each (if you're going for galaxies). And at that point, luminance must have a MINIMUM of 2 hours to not *add* noise to that image.

IMO you should go for luminance only if you're prepared to double your imaging time to add it and bring out clean faint objects and structure. Maybe the more experienced here would disagree.

 

Both of these images look great however, and I'd agree with you that LRGB and RGB seem very similar indeed.

[old_eyes]

Unfortunately, this is a syndicated pier in a remote observatory. Once you have decided on the data collection plan, you have to wait until the data is availabel, and then reject the poor quality subs. This set of runs was affected by high haze and soke cloud so a lot of subs had to be rejected. I ended up with 3.25 hrs blue, 2.5 hrs green, 4.75 hrs red and 1,75 lum. So weak on the lum compared to the rest. I will resubmit for further lum subs to try and get a better result.