pfile
IC434 and Barnard 33 (horsehead) Ha-RGB
Horsehead Nebula (IC434) in Orion. captured using LB-0001 (lightbuckets.com 24" f/8 R-C telescope). camera is the Apogee Alta U42: 2Kx2K pixels.
11/19/2009-11/23/2009 in Rodeo, New Mexico, USA.
Filters: L(RGB) = Ha(R:G:B)
Exposure: 3360s(960s,1080s,1440s) = 8x420s(4x240s,6x240s,8x240s)
CCD Binning: L = 1x1 bin; RGB = 2x2 bin
L and R, G, B stacks using deepskystacker.
L and R, G, B histogram stretches using pixinsight core 1.5
L: curve and a trous wavelets for sharpening.
RGB merge, histogram stretch/align and curves in pixinsight
L-RGB registration and LRGB merge in pixinsight (L=0.63,R=0.82,G=0.88,B=0.88)
lots and lots of cleanup in photoshop CS - to fix internal reflections and ccd bleed.
final tweaks and color balance in lightroom 2
comments: color subexposures were way too long, resulting in a ridiculous amount of star halo and ccd bleed on the 3 largest stars. this took a lot of work in photoshop to undo, and it's still obvious that there was a big problem there. this was especially bad in the blue channel, hence the purple cast around the big stars.
IC434 and Barnard 33 (horsehead) Ha-RGB
Horsehead Nebula (IC434) in Orion. captured using LB-0001 (lightbuckets.com 24" f/8 R-C telescope). camera is the Apogee Alta U42: 2Kx2K pixels.
11/19/2009-11/23/2009 in Rodeo, New Mexico, USA.
Filters: L(RGB) = Ha(R:G:B)
Exposure: 3360s(960s,1080s,1440s) = 8x420s(4x240s,6x240s,8x240s)
CCD Binning: L = 1x1 bin; RGB = 2x2 bin
L and R, G, B stacks using deepskystacker.
L and R, G, B histogram stretches using pixinsight core 1.5
L: curve and a trous wavelets for sharpening.
RGB merge, histogram stretch/align and curves in pixinsight
L-RGB registration and LRGB merge in pixinsight (L=0.63,R=0.82,G=0.88,B=0.88)
lots and lots of cleanup in photoshop CS - to fix internal reflections and ccd bleed.
final tweaks and color balance in lightroom 2
comments: color subexposures were way too long, resulting in a ridiculous amount of star halo and ccd bleed on the 3 largest stars. this took a lot of work in photoshop to undo, and it's still obvious that there was a big problem there. this was especially bad in the blue channel, hence the purple cast around the big stars.