Originally Posted by
Dave Humphries
Difficult to fault the capture Martin (well done),
Canon 7D at 280mm (440mm FFE), Manual exposure, 1/4,000 sec, f/5.6, ISO 640.
I guess my only comment is that if mine, I'd have cleaned the noise in the sky fairly early in the RAW PP workflow to avoid the blotchiness we see, using Neat Image. If it was shot jpg (back in June 2010) however, that makes the job harder - because the jpg will have 'baked-in' the sharpened noise, along with jpg artefacts.
The file appears to have an interesting history; shot in 2010, processed in PS CS4 at the time, reprocessed in PS CS5 in Oct 2016, then LR 5.7 in November 2016, so perhaps what I suggest isn't possible (esp. if jpg capture), but if you do still have the original RAW file (.cr2?), perhaps start over with processing?
HTH, Dave