The EOS 7D's viewfinder is noticeably larger than that of the 50D. As usual it features dioptre adjustment and an eye cup that can be removed to make way for alternative accessories. Unlike the 5D Mark II, the 7D does not accept replaceable focusing screens, instead using a transmissive LCD to display a wide range of information in the viewfinder.
The viewfinder gains permanent display of the ISO sensitivity, plus a little 'D+' symbol that indicates whether Highlight Tone Priority is active and a more detailed battery status indication.
In automatic AF point selection mode the AF points chosen by the camera are highlighted briefly when you initiate AF (half-press shutter release / AF button), otherwise the selected AF point is highlighted. In automatic AF point selection mode the AF point will only highlight once an AF lock has been achieved. With a single AF point selected it will blink once as you half-press the shutter release and once more upon AF lock (or not at all if no AF lock was possible). In AI Servo AF mode (with the shutter release half-pressed) the active AF point is displayed.
Exposure / Exposure comp. scale
AE lock / AEB in-progress
Highlight tone priority
High-speed sync (FP flash) / FE lock warning
White balance correction / WB bracket
Flash exposure compensation
Maximum frames in a burst
One figure hidden away in every SLR's spec is the size of the viewfinder (often in a format that makes comparison between competing models impossible). The size of the viewfinder is a key factor in the usability of an SLR - the bigger it is, the easier it is to frame and focus your shots, and the more enjoyable and involving process it is.
Because of the way viewfinders are measured (using a fixed lens, rather than a lens of equivalent magnification), you also need to take the sensor size into account, so the numbers in the diagram below are the manufacturer's specified magnifications divided by the respective 'crop factors'. As you can see, the result is that the EOS 7D has a viewfinder a (very tiny) fraction smaller than the Nikon D300(S), quite significantly larger than the Olympus E-30 and (obviously) smaller than the full-frame camera in this comparison, the EOS-1Ds Mk III. It's also noticeably larger than that on the EOS 50D.
Compared to other Canons
Compared to its peers
Roll your mouse over the above buttons to compare the size of the EOS 7D's viewfinder to other Canon DSLRs or its peers. As you can see, it's larger than the EOS 50D but essentially the same as the Nikon D300S.
Along with the Nikon D300 and D300S, the Canon EOS 7D joins a fairly exclusive club of DSLRs that offer 100% field of view. As a result, you get to see exactly what the sensor will record, helping optimize composition.