Switching between MF & AF effects correct light metering on 1Ds-Mk3

Started May 9, 2008 | Discussions thread
OP astirusty Contributing Member • Posts: 962
Re: Center-Weighted Average

Gao Gao wrote:

I think when the lens is switched to MF, the camera use CWA instead of evaluative.

I just tested this, it is not.

What I found was that if you switch from evaluative metering to Center-weighted average metering with the lens set for manual-focus, you will THEN get nearly the exact same exposure meter readings you get when using evaluative metering with only the center AF point selected and the lens set for auto-focus.

With the above result in mind, I went back and tried to find a metering mode with the lens set for auto-focus that would give the same (or approx. same) exposure metering readings I got with the lens set for manual-focus. I went through all the metering modes and none would come close. Of interest is that most metering modes gave nearly the same exposure meter readout (at least in this one indoor setting/scene). All the metering modes indicated the image would be under-exposed if I used the same shutter/f-stop settings I got with manual-focus and evaluative metering.

All this tells me that there is a problem when using evaluative metering, with manual focusing. A problem Canon needs to address.

For now, my advice is if your going to use manual-focusing then pick any metering mode but evaluative otherwise your going to get incorrectly exposed images. Depending on the setting/scene (lights, darks, shadows, etc) some images may be close to the correct exposure, while others may be off by + - 2 f-stops.

Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow