Whenever a company like Sony comes out with a statement to the effect that AF subject ID is “improved by 40%” in a new model, I wonder how on earth they quantify such a thing. Sure, stabilization can be fairly objectively measured by shutter speed. But subject identification? Really?

The a7cII, over a substantial period of use, appears to be a notch better with bird AF than the Canon R5 or the a7IV, but that’s my subjective observation. I see improvment in acquiring focus through foliage as well as stickier tracking on birds in flight. But there’s no way I could put a percentage on the amount of improvement.

In fact, if Sony doesn’t bring an a7V to the marketplace soon, I may add an a7IV to the arsenal as I really need a bigger EVF. The resolution isn’t all that important; but the size of the finder, .5″ as opposed to .39″, makes a nice difference to my eyes. And it is quantifiable. So is the fact that it’s centered on the body (my preference) rather than offset. Bird AF on the a7IV, which I owned previously, kept me satisfied in the field—maybe not quite as good as the a7cII, but it did the job.

The big thing for both cameras is that the sensor is the best I’ve seen (subjectively and unquantifiably) for bird feather details. One of my all-time favorite critter shots is a nicely-detailed, somewhat distant capture of a Straw-Headed Bulbul I got with my previous a7IV.

How much “better” is that sensor in recording bird feather details? I don’t know. Make up a number. Seems like that’s what everybody does these days.

a7cII/70-200mm f2.8 GM II/2X . . .