[wim]

Yes it does, that's also the only way to have any kind of grid inside the viewfinder.

 

I think it's f/2.5 with standard screens and f/1.2 with special manual focusing screen, which is pretty pointless most of the time because either the lens or the mirror or the screen won't be in calibration with the image sensor, giving you back/front focus.

 

Hmm, last time I checked it actually was around F/5.6 and around F/2.8, the latter with the laser matte precision focusing screen, the one that loses approximately a stop and a half in the viewfinder. Unless you want a really dark viewfinder, it won't get any better - the coarser the finish, the brighter and the more DoF you see, the finer, the darker and less DoF. However, in order to be able to focus manually, you still need to be able to see what is going on .

 

I think this is a real beauty when it comes to judging DoF in a viewfinder - you can't, essentially, unless you always shoot at the apperture apprpriate for a specific focusing screen . Do note that the aperture of the lens does not matter at all, except when it is smaller than whatever the focusing screen is made for - another reason why it is approx. F/5.6 for the standard focusing screen - it'll work just fine with all EF lenses.

 

Kind regards, Wim