| 摘要 |
PROBLEM TO BE SOLVED: To correct an error caused in a photometry value by revising an aperture diameter in the case of photometry. SOLUTION: When exposure measurement is started for a CPU 1 for image pickup, at first an exposure control section 6 fully opens a blade 2 by using a motor 3 driving the blade 2 to set the aperture to be F2.8 as a pre-processing. First photometry is conducted, a 1st photometry value Evl is obtained and a photometry value Ev1' below the 1st photometry value Ev1 is obtained to separate it into an aperture Av1' and a shutter time Tv1'. The blade 2 is driven based on the aperture Av1' to revise the aperture. Second photometry is conducted and an exposure errorΔEv due to variation in the diameter of the blade 2 is obtained based on the 2nd photometry value Ev2 and the photometry value Ev1'. A shutter time Tv2 is obtained based on the shutter time Tv1' and the exposure errorΔEv and image pickup is conducted by using the shutter time Tv2.
|
