So last night I acquired about 3.5hrs of data on M27 using a l extreme filter, having previously got rgb data on a previous session now I’m assuming I need to stack all the data together then extract channels using compose mode , or do I stack and align separate stacks from each session assuming they align the same , what’s the thoughts on this .
Dave
Data from two sets
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Mike in Rancho
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Re: Data from two sets
I'm doing something similar right now, but on the Cocoon, so different take for a different target, I imagine.
I think M27 is tailor made for the duoband and bicolor, so what is your intention for the RGB? The stars?
The Cocoon is not an OIII target it seems, pretty much broadband RGB plus Ha. Actually some nice deep background Ha too if you can get it (which I do not believe I did lol).
So I have 5 hours of RGB over two nights, group calibrated/stacked in DSS. I have 3 hours of L'eNhance, also separately stacked in DSS.
Each was previously processed in ST just to see what was there. In order to register these stacks in DSS, they first need to be the same pixel width and height. So after seeing how the two stacks related to one another, I chose how I was going to crop the wider/taller one (luckily the same file was both). I used ST for that, after extracting the red channel for Ha by loading the file into red in compose. I'm not entirely sure yet I did it properly, as all the instructions I ever see (there are many) are silent as to what to select in the luminance/chrominance box in compose. So for this one I just left it. If it doesn't work I'll go back and change it to something else.
I also used ST to open and save the RGB (but selecting linear so as not to lose the color), so both files are similar 16 bit tiffs.
Then I loaded both into DSS as light frames. Ran registration. Selected one as the forced reference frame. Then ran two stacks, each of them with only one file checked. The output files are now registered, though you will still need to crop those stacking artifacts after compose in ST.
The first time I tried this last night, I used that Ha file as L, then the color file was loaded into R, G, and B, and the extra detail added to the Cocoon was great. Only problem is it muted the colors and turned the nebula pink instead of the deep red original. The stars and starfield also lost their pop.
I will try again but compose as L, RGB (not L plus synthetic L) and see if that helps. I think in color I can also try out RGB ratio and see what that does as well.
Anyway, that's my process and intent with separate RGB and L-filter stacks. But again this target seems like it will lend itself to this. On M27 I'm not sure, since the bicolor on that usually looks pretty awesome as is. RGB stars are always nice, but a bit tricky the couple times I've tried it.
I think M27 is tailor made for the duoband and bicolor, so what is your intention for the RGB? The stars?
The Cocoon is not an OIII target it seems, pretty much broadband RGB plus Ha. Actually some nice deep background Ha too if you can get it (which I do not believe I did lol).
So I have 5 hours of RGB over two nights, group calibrated/stacked in DSS. I have 3 hours of L'eNhance, also separately stacked in DSS.
Each was previously processed in ST just to see what was there. In order to register these stacks in DSS, they first need to be the same pixel width and height. So after seeing how the two stacks related to one another, I chose how I was going to crop the wider/taller one (luckily the same file was both). I used ST for that, after extracting the red channel for Ha by loading the file into red in compose. I'm not entirely sure yet I did it properly, as all the instructions I ever see (there are many) are silent as to what to select in the luminance/chrominance box in compose. So for this one I just left it. If it doesn't work I'll go back and change it to something else.
I also used ST to open and save the RGB (but selecting linear so as not to lose the color), so both files are similar 16 bit tiffs.
Then I loaded both into DSS as light frames. Ran registration. Selected one as the forced reference frame. Then ran two stacks, each of them with only one file checked. The output files are now registered, though you will still need to crop those stacking artifacts after compose in ST.
The first time I tried this last night, I used that Ha file as L, then the color file was loaded into R, G, and B, and the extra detail added to the Cocoon was great. Only problem is it muted the colors and turned the nebula pink instead of the deep red original. The stars and starfield also lost their pop.
I will try again but compose as L, RGB (not L plus synthetic L) and see if that helps. I think in color I can also try out RGB ratio and see what that does as well.
Anyway, that's my process and intent with separate RGB and L-filter stacks. But again this target seems like it will lend itself to this. On M27 I'm not sure, since the bicolor on that usually looks pretty awesome as is. RGB stars are always nice, but a bit tricky the couple times I've tried it.
Re: Data from two sets
Hi Mike I’d like to keep as much signal as possible so I was thinking of rgb stars and as much Ha /o3 signal from the first set as possible , but chose m27 so I could compare the difference the l extreme makes compared to un filtered using my zwo533mc, I will have a dabble over the weekend and see what data I have .
Dave
Dave
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Mike in Rancho
- Posts: 1166
- Joined: Sun Jun 20, 2021 10:05 pm
- Location: Alta Loma, CA
Re: Data from two sets
Hi Dave yeah that makes sense, nothing wrong with dabbling. I think it would look good too for target enhancement but RGB stars as is.
My dabbling with Ha as L did not work out as well as I hoped. Even trying L, RGB in compose as well as RGB ratio in Color. It was better, but still quite a bit of pink/muting going on. Not even close to the deep coloring of the RGB-only version, though again it did provide better details in the nebula.
Back to the drawing board I guess.
My dabbling with Ha as L did not work out as well as I hoped. Even trying L, RGB in compose as well as RGB ratio in Color. It was better, but still quite a bit of pink/muting going on. Not even close to the deep coloring of the RGB-only version, though again it did provide better details in the nebula.
Back to the drawing board I guess.