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2013: NGC 6888; The Crescent Nebula in H-alpha
Image details
Date: June 6,7, and 8, 2013
Exposure: 6 hours (18x 20 min), ISO800, 12 Darks, 30 Flat darks, and 30 Flats

Telescope: 8" Skywatcher Newton
@F/5 with MPCC and Baader 7 nm Ha-filter 
Mount: NEQ6-pro, controled by EQmod/CdC, guided by  QHY5/9x50 Finder Guider/PHD
Camera: Peltier-cooled Canon 350Da 
Location: Emmen, The Netherlands

High resolution: (2,50 Mb)
DSLR-LLRGB post-processing luminance workflow  according to Scott Rosen's video tutorial:
 
Original 32-bit floating point RGB image in Photoshop CS3:
 -Convert to 16-bits greyscale
 -Convert back to RGB [RGB reconvertion is only done for easy of interpretation of PS histgram and tools]
 -Star repair
 -Levels correction for background blackpoint
 -Curves, selective on weak Ha clouds in the background and Ha whisps in NGC6888, with anchored background and highlights, 2x normal curve
 -High pass filtering on the details in NGC6888 (40px & 8px; Don Goldman method)
 -Carboni's v1.6 Deep Space Noise Reduction [Removes noise from background, not DSO]
 -Screen Mask Invert to further bring out faint Ha nebulosity
 -Curve (anchored background)
 -GradientXterminator (med/low and fine/med)
 -Levels (blackpoint restoration)


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