These are the Egrets I took at the same time as yours .
If you look close enough there is noise in the sky , these were taken at ISO800.
I wonder if it's easier to spot noise in a plain large colour like the sky, if the background is
busy the noise my be there but harder to spot.
My egret shot is at 1600 iso but I would say the original unprocessed file is but not as poor as the ducks and stonechats, they are completely unusable. After checking my images there are about 9 out 400 that are OK, but those 9 still aren`t very good.
