T2i Why do I get different readings?

[DDirector]

When I look at the live view mode, I will get one exposure result (lets say its perfectly exposed)
When I look through the viewfinder, it is underexposed.
It is usually lower than in live view mode.

Example (histogram shows it is perfect):
Live view: +2
viewfinder: +1
Video Mode: +1 1/3

*The camera is steady, has the same setting for all modes. Same lighting, etc.

My histogram is set perfectly. Nothing is over exposed, or underexposed - Its perfectly in the middle. But, the reading is usually overexposed. To be sure, I should be relying my exposure on the histogram?

 

[mr bill]

Tricky. I have a 60D and use the histogram all the time, which gives me a +2 stops overexposure reading on the camera meter. My real world reference are the calibrated broadcast crt monitors at work, and all looks good on these, so I'm going with the histogram from now on. Can't be more helpful with the anomalies you describe, I'm afraid.

 

[DDirector]

that's cool.
thanks for the input