Back to your photography classes Adam. The larger the f-stop, the *shorter* the depth of field.

The only thing missing from Allan's list (which he covers by talking about focal lengths) is to insist that if you want limited dof go for the biggest chips (or film gate) available.

tom.

WIKIPEDIA (depth of field):

"For a given subject framing, the DOF is controlled by the lens f-number. Increasing the f-number (reducing the aperture diameter) increases the DOF."

Ah, language at play here. When I said 'larger the f stop' I was talking about the diameter of the aperture. Philippe's use of 'Increasing the f-number' refers to the higher numbers associated with smaller apertures, f/11 as against f/4, say. Sorry for the misunderstanding.

tom.