Manual focus confirm on 600D (T3I)
I tested this today with a reversed lens.
Actually the focus confirm does not work with old objectives, unless they have AF.
Apparently you need some kind of AF chip to cheat the Canon into thinking that it's actually connected to something electronic. Then the confirmation works to some degree.
Fortunately those modchips didn't look too expensive or too difficult to install.
I just discovered after 3 months (may not be alone:-))
Focus confirm in manual mode works even with the old fifty 1.4
I never tried on the my previous models 450D, 550D
But, works fine on the 600D (LED and beep)
I can confirm it works on 450D too. It uses the phase detect sensor on the camera, so if enough light is available it should be able to focus confirm many objectives including the old objectives which lack automatic focus.