How to tell which focusing Screen in 5D

I bought a Ee-S focusing screen for my 5D, hoping to have better manual focus precision with fast lenses. However, when I installed it, I did not notice any change whatsoever. The new and old screens are identical in appearance, and I don't notice any change through the viewfinder.

I bought the 5D secondhand and it is possible that it already had the Ee-S. the Custom Function was also set to Ee-S already. Is there a definitive way to tell?

Dan C wrote in post #10676473
I bought a Ee-S focusing screen for my 5D, hoping to have better manual focus precision with fast lenses. However, when I installed it, I did not notice any change whatsoever. The new and old screens are identical in appearance, and I don't notice any change through the viewfinder.

I bought the 5D secondhand and it is possible that it already had the Ee-S. the Custom Function was also set to Ee-S already. Is there a definitive way to tell?

A good chance that the screen fitted is an Ee-S then

If the screen fitted and the one you've bought are genuine Canon there should be an 'S' stamped on the tab you grasp when removing and installing the screen.

There should be a big difference. objects out of focus on the Ee-S screen should be REALLY blurry.

The one i bought definitely has the "S" stamped on it. The one in the camera does not have anything on the tab. But when installed I notice no difference.

Would there be any difference in exposure? If I take two pictures with manual exposure, would they be noticeably darker or lighter?

I would expect the EE-A to be overexposed especially if you use it at f8 or higher.