[lister6520]

I find the placement of the AF button ideal. I don't think there is any better place to put it actually. The only change I would make is to make it a bit larger and have a bit of a hollowed out depression in the boy below it to allow the thumb to settle on it more comfortably and flatten the hump just below the AE lock button as that one

One of the best things about it is the way it sits right in between the rear dial and the AE button - it makes those three controls reachable with minimal movement of the thumb, the space between the AF button and the dial being at the exact place where the tip of the thumb rests naturally. To focus I don;t even move my thumb from there but just press the AF button with the right side of my thumb. QUick adjustments to the left dial can be done with very little movement.

I think they thought a lot about it and perhaps those who are finding it to be in the wrong place might just be finding it difficult to adjust from the different placement on earlier cameras, which while probably less ergonomic they had gotten used to.

It may also depend a lot on the dimensions and proportions of one's hand so maybe what is a perfect fit for me might not be so for everyone.

[monochrome]

This is so funny (to me)... I have never taken my glasses off to shoot, I just always press right up against the eyecup and leave the diopter zero'd.

Of course, I'm a left-eye shooter too, so I'm weird.

We're hijacking the OP's thread, which I started, so we really ought to stop.

For me the rear AF button is just different. I want to move my thumb to where the e-dial is. Perhaps the shape of the thumb rest doesn't perfectly lend itself to natually moving my thumb to the AF button, but once I learn the placement it will surely feel natural.

[Rondec]

I think it is OK -- better actually, when you get used to it, than the placement on the K5. The only problem is that I shoot with both cameras and the body shapes are similar enough that my muscle memory gets "confused," and I end up having to look for the auto focus button.