I have found a pretty quick work around. It looks like this will work on Canon 5D MkII, 7D and 50D. These cameras have custom modes that you can set up on the exposure mode dial. In the case of the Canon 5D MkII and 7D, there are three selections you can set up. The 50D has two. I have C1 set up to shoot RAW, black and white, ISO 100 at f5.6. I have C2 set up to shoot RAW, black and white, ISO 2000 at f2.8. I have C3 set up to shoot RAW, color, ISO 100, F8.0, and mirror lock up engaged.
It's pretty simple to set up actually. Set up your camera like you're going to shoot and choose the parameters you most like to use. Make sure to engage mirror lock up through the menu. Somewhere in the menu is something like "camera user setting". Choose that then choose "Register". Next choose "Mode dial :C1", "Mode dial :C2"or "Mode dial :C3". The condition the camera is in when you register settings is how the C selections will register. Voila! Set up is done. If your had mirror lock up engaged when you registered user settings, you can simply select your C selection on the exposure mode dial and you're ready to shoot with mirror lock up!






