My BrightScreen #5 came today! It also came with a shim and a message stating that most 5D bodies don't need it...but occasionally a body will to ensure proper focusing.
Wouldn't you know...mine needed it! Glad they provide that!
I had the Ef-S screen before to aid in manual focus for macro stuff. Basically this screen is a whole different look. It is WAY brighter! With an F4 lens...I can now see in the dark! Only in the center though. With my 35L the whole screen is virtually the way I see the scene with my eyes. Very bright.
This screen was a bit weird for me to get used to. Having a big circle in the center now that constantly makes things extremely noticeable if out of focus is new to me. After a few minutes it starts really making sense. I don't think I will want to use anything else soon!
I almost want to always use a tripod now to make sure its perfectly in focus! You can REALLY tell with this thing. I totally recommend this. Its a bit pricey...but you won't be questioning your focus anymore. And you will have a super bright viewfinder, even with an F4!

