50mm Summicron on a Canon 1Ds MKII Exposure Lock

[rich_weiss]

I have placed a 50mm Summicron on a Canon 1Ds MKII, however

depressing the shutter button half way does NOT lock the exposure.

Does anyone have any suggestions other than metering manually? thanx

[PuppyDigs]

Well, if you want to use an all manual lens but don't want to use M mode to hold your

metering, use human memory and turn the QCD for EC. That is, note the meter reading,

recompose and dial in EC to regain the original reading. Of course, it would be faster and

simpler to use M mode. Even simpler to mount an EF 50 1.4 USM...

[rich_weiss]

thanx for your quick response - the * button seems to work just fine for me, I tried custom function 4, but it seemed to keep my Canon lenses from autofocusing to my needs.

[Greg M]

In order for a Leica lens to work in anything other than manual modes you have to have some sort of means to automatically stop the lens down. Canon bodies do that electronically via one of the contacts within the mount, so there's no body lever to mate with a Leica R lens aperture mechanism to stop it down, and M lenses have no auto aperture mechanism. For that matter all communications between EF lenses and Canon bodies are electronic, something a Leica lens would have no means of doing. I'm not sure how you expected to be able to use anything other than manual.