I've been pretty absent from the forum for a while but I thought I'd share another of my reworkings of the Hubble Space Telescope's data.
The aim with this one was a natural looking colour balance, a little 'sparkle' from those young blue stars, clarity of the dust lanes and the addition of enhanced hydrogen emission nebulosity. The image below is merely a thumbnail, albeit one that's 1024 pixels widel: I have provided a 5750 pixel wide version (50% scale) which you can access by clicking here
M51, a.k.a. The Whirlpool Galaxy
The following HST unstretched files were used: Red
. With the RGB channels mapped to Hubble's 814w, 555w and 435w filters saturation out of the tin was a little high and the initial colour balance was rather too cyan/blue. Adding the Ha data, processed with PixInsight's HDRMST tool to reduce the background brightness in the cores and spiral arms, helped correct the colour balance. Processed entirely in PixInsight and Photoshop CS6.
If you'd like to read a little more about M51 then this
Wikipedia's article is a good starting point.