Learning Moment...Bright core with dim outer shell

[sreilly]

Happy Easter!

I've collected the start of my attempt at IC4677, The Cats Eye Nebula and managed 3.5 hours of Ha so far. I'm using a 12.5" f/9 RC and STL-11002C CCD camera. The exposures are 30 minutes each. Together I get a decent outer shell although more time is needed while at the same time the core is very bright. Using HDR with 4 layers brings out some nice detail but I loose the outer shell. Layering is one way I use to help solve these issues using PS but I need to find the proper way to do this in PI. Any suggestions welcomed.

Thanks,

Steve

[jkmorse]

Steve,

Have you tried boosting the number of layers.  I am working on a HDR blended image of M42 and, when I get to the HDR Transformation stage, I need to use 7 layers to pull out all the detail in the image.  Then apply a nice little contrast boost with CurvesTransformation and you should be all set.  But experiment with the number of layers in HDR since it can make a huge difference.

Hope that helps,

Jim

[RickS]

How about constructing a mask that only exposes the bright core?

[msmythers]

One other method that comes to mind is to treat objects with high core brightness like we do with M42 and the Trapezium.  Shorter exposure times for the bright core details and the longer for the fainter areas. Then use HDRComposition to integrate the images into a high dynamic range image.


Mike