The last two are certainly an improvement on the first couple.


Personally I prefer the third photo. The transition from lights to shadows is more gradual and the shadows a little less harsh. The light reflecting off the rim of the glasses is also good. Seperation from the background is nice, you can still work out that he's in some sort of library but the focus is on him as the subject so it's applicable to the context.


I'd probably try to increase the exposure slightly and tell him to brush his hair or something![]


Other than that, one thing to look out for is to make sure the glasses frames don't obstruct his eyes like it does in the last photo, I find it a little distracting.


You could also lower the temperature ever so slightly, it's a little warm for my taste but that's getting a bit nit-picky.


Good luck with the shoot anyhow, I think you've done a pretty good job overall.


Ben.