Hi Dan. Yes, I too can see some small patternlike things in the blue. But If you hadn't mentioned them I would probably haven't noticed them as the bird looks very nice and as soos as I looked at the image my eyes immediately went to the bird.
Thanks, Binnur. Yes the pattern is very subtle, whatever it is. And not really noticeable on casual viewing.
Would a noise reduction of the blue help? THe owl is in a great position plus eyes open!
Thanks, Allan. I ran this one through Topaz AI Sharpen which does NR. The 16 bit version looks good down to full rez. But obviously there is something in the underlying data that comes out during the conversion to 8 bit RGB. Drat. Now it's a mystery to be solved

I'll try processing without the AI Sharpen and see what it looks like.
I like blue sky BGs and shots from different angles as long as they show eyes and feather detail and your shot does both and very well
Thanks, Randy. I must say that snowies do present well against a blue sky. And as you said it really comes down to position of the bird and the detail.