The image above was taken with the Canon PowerShot G7 at 9mm f4 and with a sensitivity of 100 ISO; the original JPEG measured 5.23MB. The original image used for the EOS 400D / XTi crops was taken at 24mm f8 with a sensitivity of 100 ISO and measured 4.41MB. The apertures selected were the sharpest for each lens. The crops are taken from the upper left, center and lower right portions of the originals and presented here at 100%.

Viewed at 100%, there's greater noise on the PowerShot G7's crops even at 100 ISO, apparent as a textured effect across the first crop and in the water on the second. The 400D / XTi's samples at first appear softer, but upon closer inspection contain a similar level of detail with the smoothness coming from lower noise.

In the G7's favour though, the trees in the third crop appear much more detailed than those in the 400D / XTi sample. This is down to the 400D / XTi's kit lens which can become quite soft in the corners. In contrast, the G7's lens remains pretty sharp across its frame, and so long as sensitivities are kept relatively low, its sensor can do the optics justice. Certainly while the 400D / XTi result is undoubtedly smoother, it doesn't actually contain any more detail.