-1

I meter a surface at ASA 100 and get F4 at 1/15 second. What is the illumination coming off that surface in Cd/square foot ?

marked as duplicate by Itai, AJ Henderson, dpollitt, mattdm, John Cavan May 27 '13 at 0:43

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

1

This Kodak reference for estimating luminance and illuminance may help.

Your metering at ISO 100, 1/15th and f/4 would be equivalent to ISO 400, 1/30th and f/5.6 if I've done the math correctly. So use their value for f/5.6 which is 2.67 Cd/ft2

Not the answer you're looking for? Browse other questions tagged or ask your own question.