I've tried to use some new combination of channels, to reveal reflecting dust parts of M42 nebular complex.
R = HAlpha - Continum
G = Continum
B = Continum - Halpha * 0.05
Substracting H-alpha frame from "continuum", helps to emphasize reflecting dust clouds over bright emitting hydrogen.
Source FITS used:
All images was taken in 2-3 Jan 2005. WFI camera, 2.2m telescope. HDR composition of 10 frames 30 sec and 10 x 280 sec for each filter. Also single 3sec frames per filter was used for anti-blooming. Filter 620/17 (ESO866) used as "h-alpha continuum image" (I do know that it is need to use 665/12 in pair to make real "continuum" image, but there are no such images in base, so I had a problems with clear substraction of stars with different spectral class). Stars was also detached in G & B channels for independent processing.
DARK / BIAS / FLAT calibration, WFI mosaic reprojection in IRAF. Images registration and composition - Iris. Weightened sigma-clipping addition - FITs Stacker. Post-processing and residual artifacts retouching - Adobe Photoshop CS2.
Click here for LARGE image. (5.0Mb, 50% of post-processing size, or 25% of camera resolution)