Note: This post was copied from the topic "What did you learn Today?" in Learning Photography Forum as it seemed more of a bloggy idea.
Read something the other day that I'd never heard; the idea that depth of field would remain constant as focal length changes provided the subject occupies the same portion of the image.
So, set about using the tape measure to replicate the thought into reality.
The application would be that the aperture that provides enough DOF for the squirrel at 6 feet and 98mm will provide roughly the same DOF at 10 feet and 200mm and at any other focal length if the squirrel is framed the same size.
Read something the other day that I'd never heard; the idea that depth of field would remain constant as focal length changes provided the subject occupies the same portion of the image.
So, set about using the tape measure to replicate the thought into reality.
The application would be that the aperture that provides enough DOF for the squirrel at 6 feet and 98mm will provide roughly the same DOF at 10 feet and 200mm and at any other focal length if the squirrel is framed the same size.
