I’ve got approx 6 hours of Ha and RGB data on the Horsehead and Flame Nebula.  I need more, I aim for around 20 hours.  In the meantime, I am enjoying practising processing using books and internet forums.  Processing is hard, no doubt about it, and it is starting to click for me albeit slowly.  I think the key is similar to normal photography.  The best images are made in the camera no amount of processing will make a poor photo amazing.  Anyway, here is the latest HaRGB combination of this target.

Processing Technique in a Nutshell

Linear Processing

Ha Linear:

1. Dynamic Crop
2. DBE
3. Mask and AT Noise Reduction
4. Invert Mask and Deconvolution using Star Mask and Local Deringing Support.  Generate PSF using Dynamic PSF.

RGB Linear:

1. Register against Ha Linear
2. DBE
3. Mask and AT Noise Reduction
4. Invert Mask and Deconvolution using Star Mask and Local Deringing Support.  Generate PSF using Dynamic PSF.

Create HaRGB Linear Image

Create a HaR image:

1. Extract channels of Linear RGB.
2. Use Pixel Math to create continuum map x 2. (http://pixinsight.com/tutorials/narrowband/theory/en.html)
   1. C1 = B/N
   2. Denoise using AT the C Map
   3. Use Pixel Math so Bnew = N * C1
   4. Repeat but this time C2 = Bnew/N
   5. Denoise C2
   6. Use pixel math so Bfinal = C2*N
   7. End result is HaR.

Create HaRGB:

1. Use linear fit setting original R as reference and appy to the new HaR.
2. Use channel combination to combine HaR with G and B from original image.
3. Result is HaRGB.

Non Linear Processing

Stretch the Image:

1. Use script Masked Stretch to initiall stretch the image.
2. Use Histogram to final stretch the image.  Adjust channels if needed so peaks are aligned on R, G and B.

Create LSS+SSS Using Masks:

1. Create Star Masks to generate LSS and SSS
2. Use Histogram Transformation to stretch LSS and SSS being careful not to clip any pixels.
3. Combine LSS and SSS using PixelMath LSS+SSS

Further Processing:

1. Use HDRMultiscaleTransform
2. Use LocalHistogramEqualization using clone mask and also invert
3. User CurvesTransformation for Saturation Boost and Contrast Boost with Star Mask
4. Use ACDNR

Finishing Touches in PS:

1. High Pass
2. Merge Ha with RGB again with Luminosity set to 50%
3. Add frame and text then save for web