Nice that you were able to get so close, but overall this image doesn’t really work for me. It’s far too soft to begin with (camera shake?) and compositionally it’s let down by not seeing the either the entire bird or, as a headshot, not seeing the entire beak. Others may disagree, but I’m only offering my own opinion here, so please don’t take offence.
What lens was used? Agree that it isn?t as sharp as it could be, colours aren?t as vivid either. Maybe some saturation and a tighter crop?? It is such a pity to dismiss this image, I have yet to get such a close up shot of a heron. The bird itself doesn?t seem to be the best specimen, dull eyes & lack of colour in the beak.
Maybe he needs to see the quack……haha. I used Panasonic Lumix on full zoom and also cropped in (probably too much) No worries as I said before it is all a learning curve for me and you know what they say……if at first you dont succeed. Thanks for your interest.