Loosing DOF as you enlarge

[farrique]

Please help me get this matter right. Enlarging or printing it at a larger size. I went to SVA N.Y., N.Y. and can't forget when my teacher of Photo Technics said something at class that I answered him, "so that means that when you start enlarging you start loosing DOF? he said "yes". Unfortunately I lost the book, which he wrote and forgot he's name. It was 1980. If you find out the technical aspect of this matter please let me know.
Thanks,

Farrique

[rob marshall]

You don't lose DOF as you enlarge. You do lose resolution, as the pixels (or photo grains on film) get more widely spaced. DOF is set at the time of shooting and is dependent upon the lens/camera configuration, and the distance from the subject.