I shot a dance performance tonight and my Canon 5D MkI had two twirks I found annoying.
(1) I was shooting dancers against a velvet background , so I wanted to use the AF/AE lock function with partial metering, so that I would lock the exposure when the focused locked on the dancers and recompose. However, with partial metering or center-weighted metering, the exposure would not lock with the focus, so recomposed photos were excessively over-exposed when the focus point shifted onto the velvet. When using matrix metering, the AF/AE exposure lock worked and the exposures were generally fine.
Note that custom function 04 is set to 0 (AF/AE lock).
Now it gets curiouser. At home with the flash (430EX) on the camera and switched on and the camera set to any metering mode, AF/AE works. Switch the flash off, and the AE/AF doesn't lock in partial or center-weighted metering, but is still okay in matrix mode.
2) I wanted to show movement in the dancers by using rear curtain flash synch and a relatively long shutter speed. With varying stage lighting I set the flash (430EX) at 1/16th power at 5.6 and ISO 800 to give slight underexposure for the flash at the distance I was shooting. I set the camera to Av so that the shutter speed would vary depending on the stage lighting and thereby control the lighting ratio. Problem: the shutter speed set at 1/200 whenever the flash powered up. Note that I have set the custom function 03 to 0 (auto) rather than 1 (fixed at 1/200th). I thought the flash might be overriding the camera, but a check of the flash manual does not provide any custom function for the flash that would override the camera. Now back at home, everything is fine. Was this simply due to the flash not seating properly?
I can live with the second problem, as I suspect it is a once-off. However, I have had the first problem previously.
Any suggestions appreciated.
Thanks
