focusing screen causing overexposure issues

I have canon 5dmk2 - i replaced my standard focusing screen with the Eg-S to play around with manual focus, since then I have noticed that the camera is overexposing shots. The 85/1.8 seems fine, the 135/2 overexposes by about 1 stop, the 24-70/2.8 is way overboard, last night I had to drop by 2-3 stops last night shooting landscapes.

Since this problem started when i swapped the screens, I'm assuming the new focusing screen is causing it. Is this normal and do i just need to compensate or can I set the camera to compensate for this?

I don't have the manual handy but if I remember correctly, there is a custom function that you set depending on which focus screen you have installed.

Found it..
C.Fn IV -5 – Focusing screen

awesome, thanks.

how is that focusing screen? does it dramatically improve your focusing? I have a 85 1/4 manual with an AF confirmation chip and even with that I miss focus in lowlight, and been debating getting a focusing screen and a 135mm manual to save a few bucks on the 135 L. Thoughts?

i wouldn't say dramatically, it does help but not as much as i expected it to. when i first used it I didn't notice much difference and i wondered if i bought the wrong one :P, one thing i do like is that it does help to visualize your DOF.

at least with my current lenses, i get focus confirmation through the viewfinder when i manual focus and i've been pretty accurate.

so yeah it helps but I'm not sure I'd rely on it to go full manual if i was required to produce results relying solely on the screen. for the $30 it cost it was a worthwhile investment.

mike_311 wrote in post #17668639
at least with my current lenses, i get focus confirmation through the viewfinder when i manual focus and i've been pretty accurate.

do you have to have the shutter half pressed of BBF pressed to get the AF confirmation? That is how I do it in studio but I've been doing some MF for video and would like to have the ability to get confirmation.

i manually focus and then press the button half way. if the focus is correct, the focus indicator will light up, if not, nothing happens.

mike_311 wrote in post #17668661
i manually focus and then press the button half way. if the focus is correct, the focus indicator will light up, if not, nothing happens.

yup. I will either do that, or you can also just go ahead and half press the button, then focus, when it gets in focus it will blink.