In optics, particularly as relates to film and photography, the depth of field (DOF) is the portion of a scene that appears acceptably sharp in the image. Although a lens can precisely focus at only one distance, the decrease in sharpness is gradual on each side of the focused distance, so that within the DOF, the unsharpness is imperceptible under normal viewing conditions.
I made a tumblr, not sure why, but I did, so here: bogyphobic.tumblr.com
And, since my uploads on here are so sporadic, out of order, and poorly titled, Flickr: http://www.flickr.com/photos/berlin_on_fire/
It's fall, and I'm unimaginably happy.