cybereye
16-07-2013, 09:18 PM
Hello all!!
Well, as I was far from happy with my star colours, I began investigating the best way to increase the green channel contribution which had been subdued by the UHC-S filter I use to tame LP. If I could do this correctly then I felt I could achieve my goal of restoring the colour in my yellow stars.
I tried several methods during processing to rectify the effects of the UHC-S filter but none gave me the result I was after. I always seemed to get an over-abundance of red, especially as halo's around the stars. So I struggled with just what to do.
I knew I needed to get the colour contributions right before I started processing, so I went back to DSS. In the debayering options for an OSC camera you can determine the amount of red and blue contribution, and in turn the green contribution. I played with this parameter and settled on a RGB ratio of 0.7:1:0.7.
Now it's not perfect, and the colours of the Trifid may not be to everyone's liking, but I think this is as good as I will get from the middle of the 'burbs. Such is the cross that we "Urban Imagers" have to bear!! ;)
Anyway, here's my latest repro with more yellow stars than before. I've also attached my previous two attempts with the same data - any thoughts on this latest attempt would be greatefully appreciated!
Here's the Astrobin Link (http://astrob.in/48416/) which doesn't have the compression artefacts that the attached image has...
Cheers,
Mario
Well, as I was far from happy with my star colours, I began investigating the best way to increase the green channel contribution which had been subdued by the UHC-S filter I use to tame LP. If I could do this correctly then I felt I could achieve my goal of restoring the colour in my yellow stars.
I tried several methods during processing to rectify the effects of the UHC-S filter but none gave me the result I was after. I always seemed to get an over-abundance of red, especially as halo's around the stars. So I struggled with just what to do.
I knew I needed to get the colour contributions right before I started processing, so I went back to DSS. In the debayering options for an OSC camera you can determine the amount of red and blue contribution, and in turn the green contribution. I played with this parameter and settled on a RGB ratio of 0.7:1:0.7.
Now it's not perfect, and the colours of the Trifid may not be to everyone's liking, but I think this is as good as I will get from the middle of the 'burbs. Such is the cross that we "Urban Imagers" have to bear!! ;)
Anyway, here's my latest repro with more yellow stars than before. I've also attached my previous two attempts with the same data - any thoughts on this latest attempt would be greatefully appreciated!
Here's the Astrobin Link (http://astrob.in/48416/) which doesn't have the compression artefacts that the attached image has...
Cheers,
Mario