Anybody use an Ec-B focusing screen in their 1 series?

I read in the manual that you should only use center weighted averaged metering or non-center spot metering when using this screen because the camera won't meter properly due to the prism.

I'm sure Canon is correct but has anybody used other metering modes (i.e. center spot) with success or is it completely thrown off? Or does it depend on the overall scene?

Are the ones with the prism (A, B, I and L) the best for manual focussing? That's why I'm interested in the B, but I'm kind of holding off buying a new screen until I learn more about them.

Any input is appreciated.

Yes I have it and use evaluative metering nearly all the time and cannot see any significant difference. In most cases I'm compensating manually +/- 1/3 or 2/3 to get the histogram where I want it so maybe the difference has been absorbed into my compensation but in any case I don't notice it.

I can imagine that spot metering with a slow (f/4 to f/5.6) lens may be more affected because the spot will be right on top of the split that starts to black out as the lens gets slower.

I highly recommend a split screen to anyone who cares about accurate focus because it never lies. You know instantly whether AF has hit the mark before you press the shutter ... as long as you use center point AF of course....

On a 1Ds Mk.I partial metering and the EC-B work fine. On a 1Ds Mk.II, Partial metering and the EC-B underexpose about 2/3 of a stop.

Since I now use a 1Ds Mk.II, centerweighted average metering is the route to go.

Thanks for the replies.

So by the sounds of it, any disruption to the metering should be fairly consistent and I should be able to manually compensate for it.

That's good, as I wanted one with the split prism to hopefully improve my manual focus accuracy (I don't trust my eyes too much on their own anymore).

I guess I'll order the Ec-B and try it out to see how/if I need to compensate in the different modes since it doesn't sound to be random willynilly-ness.

I keep an EC-B screen on my 1DsMkII and in spot mode there is some randomness from what I have seen, unless you have pre-focused. The radomness seems to be about +- 2/3 EV at most, but it has been awhile since I paid attention. I think it has to do with the prisms in the focus screen. However, in partial or full exposure modes I have seen no variation. I usually use center weighted myself, just because that seems to work best for what I shoot.

The center part (split prism) of the EC-b lets in too much light for spot metering to work on the center AF point. Spot metering accuracy is retained for user selected spots OTHER than the center point.

Since most should not focus recompose and if you use the AF points, spot metering is usable with a focus screen. AF accuracy/speed is never affected by focus screens.

As mentioned, centerweighted average works best on a 1Ds Mk.II with an EC-B if you are a manual shooter. If you shoot AV or TV often a exposure comp of +2/3 of a stop is needed.

I've been thinking about getting a split prism for my mark III, but waited because of metering inaccuracies people talk about. I shoot in Evaluative mode all the time. My metering will likely not be affected right? foxbat seems to think so. anyone else know?

cosworth wrote in post #3900330
AF accuracy/speed is never affected by focus screens.

Indeed. I meant that with a screen you will be able to tell how accurately your AF is performing. Thanks for clarifying.

Indeed, I can't live without one. I like to know my shot is in focus and my AF is dead on.

OK guys... thanks again for the input. I've put my order in for the Ec-B.

Looking forward to it and hopefully more accurate manual focus.

I just got my EC-B in the mail last week for my 1DM2. Should of bought it when I first got the camera.