Mmmm..... I would go for a larger aperture before I changed the ISO too..... You probably wouldn't notice much change in DOF had you dropped it down a stop or two..... and even if you did the main point of focus is the bird, not the trees in the background anyway...... Really an awesome shot! Tne other thing I noticed with your settings is the WB on Auto.... I've read in many different places it's better to not use Auto WB.... many times the camera gets it wrong. Set the WB for the actual light you're using or make a custom wb profile if you have the time before you shoot.... your original image seems very blue to me which is why I mention it.

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