Funny, after visiting the site I went straight to the comments to see if anyone else had the same feedback. It goes slightly transparent (not blank) but the standard hand/cursor pointer would be enough to let me know that the image is clickable, and the icon-forward does even more.
I suppose I might leave my mouse pointer hanging out in the middle of the screen a lot, but my intention was just to scroll through the site and look at the large pictures. Unfortunately, whatever is front and center (the one I want to look at) goes jarringly faded because my mouse is usually unintentionally hovering it. I could live with a more subtle opacity: 0.90. :)
That said, nice site. For something similar, if you have not seen it, you might be interested in builtwithbootstrap.com.