If you’ve been experiencing erratic behaviour from your Macro lens aperture in video mode on the 5DmkII then Canon may just have come up with a fix.
http://web.canon.jp/imaging/eosd/firm-e/eos5dmk2/firmware.html
Full list of changes from the Canon site:
“This firmware update (Version 2.0.7) incorporates the following improvements and fixes.
1. Fixes a phenomenon in which the aperture exhibits abnormal movement when shooting movies in manual exposure mode and Aperture Priority AE (Av mode) using some Canon lenses (such as macro lenses).
2. Fixes a phenomenon in which the exposure level shown in the LCD panel differs from what is shown in the viewfinder when shooting still images in manual exposure mode.
3. Fixes a phenomenon in which the Wireless File Transmitter (WFT-E4 or WFT-E4 II) may not automatically power off when used for FTP transfers.
These phenomenon only occur with the Version 2.0.4 and Version 2.0.3 firmware.”
Below is a video of the issue that I hope the firmware fixes.