To compare real-life performance we shot the same scene with the Nikon D80 and Canon EOS 400D / Rebel XTi within a few moments of each other using their best quality JPEG settings, Auto White Balance, default tone and sharpening, and 100 ISO sensitivity. The D80 was set to Matrix Metering and the Canon to Evaluative Metering. Exposure compensation was set to zero.

Both cameras were fitted with their respective kit lenses: the DX 18-70mm for the Nikon and the EF-S 18-55mm for the Canon, each set to f11 in Aperture Priority mode. The crops are taken from far left, center and far right portions of the originals and presented here at 100%.

Nikon D80 with DX 18-70mm		Canon EOS 400D with EF-S 18-55mm
18-70mm at 27mm, f11 (40mm equivalent)		18-55mm at 25mm, f11 (40mm equivalent)

Before even looking at the crops below, both cameras have clearly metered quite different exposures for the same composition; indeed there’s a whole stop between them. Judging from the original images and the crops below, we’d say the Nikon is closest to the technically ‘correct’ exposure, although subjectively is perhaps 1/3 of a stop overexposed. In contrast the Canon 400D / XTi has underexposed by 2/3 of a stop, or a whole stop if you consider the D80 example to be spot-on.

There have been several reports of the 400D / XTi underexposing, although this was the most dramatic example we’ve come across. Interestingly though, the same scene taken a few weeks earlier for our original 400D / XTi review did not phase its metering system, and all our 400D / XTi Gallery shots are exposed perfectly. It is an issue potential owners of the 400D / XTi should be aware of though. In the meantime, we have used compensation to match the exposures between the D80 and 400D / XTi on our outdoor noise results page.

A difference in exposure aside, the crops below reveal greater detail in the favour of the D80; this is especially apparent on foliage in the third crop taken from the lower right corners of the originals.

This particular effect though is almost entirely down to the lens. As our resolution tests on the next page show, the Canon 400D / XTi loses up to 7% of its potential resolving power when coupled with the budget EF-S 18-55mm kit lens. The Nikkor DX 18-70mm lens used for the outdoor test shots in this review is far superior and makes the most of the D80’s sensor.

Fit the D80 and Canon 400D / XTi with optics which out-perform their sensors, and both cameras resolve essentially the same level of detail. This page does however prove the importance of choosing a decent lens if you’d like to make the most of your camera. The Nikkor 18-70mm lens is much more expensive than the Canon EF-S 18-55mm, but you clearly get what you pay for. To see how the 400D / XTi benefits from a superior lens, see our Canon lens group test.

You may wish to also compare results taken from the same scene, albeit on a different day, using the Sony Alpha A100.

Nikon D80 with DX 18-70mm		Canon EOS 400D with EF-S 18-55mm
1/80, f11, 100 ISO		1/160, f11, 100 ISO
1/80, f11, 100 ISO		1/160, f11, 100 ISO
1/80, f11, 100 ISO		1/160, f11, 100 ISO