Monthly Archives: August 2011

M51 Aug 26, better blue, better processing

M51-V3-Aug2011-CropI re-did the blue channel in 3-minute subs, getting 27 of them before the target sank below my hedge. This larger number of subs reduced the noise in the channel quite a lot (although it is still a bit noisy).

Also reprocessed more carefully, especially by taking the individual colour channels into Photoshop and removing the skyglow gradient from each (using Gradient Xterminator).

This is starting to look good; I’m pleased with the direction. If there are more chances this season, I’ll add more subs in all the channels.

M51 LRGB colour, first draft

M51-Colour-Balanced-1I have gathered at least some data now for 3 colour channels and luminance, and did a first combination tonight. It needs more colour data to improve the signal-to-noise ratio, especially in the Blue channel which was taken through light cloud and is very noisy. However, it’s still quite pretty and I’m pleased with the result so far.

This would be 90 minutes of Luminance, and 60 each of Red, Green, and Blue binned 2×2.  QSI583 camera on an AT8RC, autoguided with a Lodestar, all on a Losmandy G11.