Hi Steve,
I note the shutter speed was 1/50s, so even without IS, it complied with the 1/(FF eq FL) rule of thumb - although I appreciate that doesn't guarantee a sharp shot.
Can I be an absolute swine?
I think the subject
does look a bit soft, well, softer than the trees.
It is possible the deer 'twitched', however, I think you may be able to improve things with slightly different sharpening regime.
Looking at the picture, I think you sharpened with too high a threshold because the higher contrast edges (tree branches, etc.) are reasonably well defined, but anything with lower contrast (leaves, etc.) looks distinctly 'mushy', including the poor old deer.
At iso160, I wouldn't have thought you'd need so high a threshold to avoid sharpening noise.
Also, (I did say I was going to be an
absolute swine, didn't I?), I am 'troubled' by the foreground branch top right; it is very prominent and sharper and more contrasty than the subject. I would be tempted to blur it significantly and reduce the contrast by toning down the bright top edge.
If you want to really mess with reality; taking a clone brush to the end of it might be an idea, it currently points out of the top of frame - compositionally, wouldn't it be nice if it pointed (at least) slightly towards the deer?
BTW, what is your secret, how can you get that close?
Were you in a hide?
Or are you a deer too?
Seriously though, I hope that reads as constructive help and not bashing a lovely image.
Cheers,