Canon S120 Optics

Canon S120 Optics

Sharpness: All four corners are only somewhat soft at full wide angle at f/1.8 while the center is sharp, which is very good performance especially for 24mm equivalent at f/1.8. And some of the softness is due to strong distortion correction, both geometric and chromatic aberration (see below for uncorrected results). Stopping down improved corners a bit, but not as much as you may expect because of the strong distortion correction.

Corners are sharper at full telephoto (120mm eq.) wide open, and the center is sharp, however perhaps not quite as sharp as wide angle. Again, this is very good performance for a 5x lens at 120mm equivalent.

Some very minor corner shading ("vignetting") can be seen from the slightly darker corner crops.

Very good performance overall, especially for a 24-120mm equivalent lens that's so fast at wide angle. The lens is a little on the dim side (f/5.7) at full telephoto, though. The following table reflects the maximum and minimum apertures at various focal lengths as reported by the camera:

Geometric Distortion: The Canon S120's JPEGs exhibit a moderately high amount (~0.8%) of barrel distortion at wide angle. At the telephoto end, JPEGs exhibit much lower geometric distortion, only about 0.2% barrel.

In uncorrected RAW files, barrel distortion at wide angle is very strong at about 5.2%, while at telephoto barrel distortion is still low at about 0.2%. That's not unusual, though, and most RAW converters should automatically correct for it, but strong correction does lead to some extra softness in the corners.

Chromatic Aberration: Chromatic aberration in camera JPEGs at wide angle is moderate in terms of pixel count, but coloration is quite muted so overall the effect is quite low. Fringing at full telephoto is slightly lower in pixel count, and again quite muted and therefore low in appearance.

As you can see from the uncorrected RAW crops, chromatic aberration is actually fairly high and bright particularly at wide angle, so the Canon S120's processor does a good job suppressing most of it in JPEGs, though as mentioned above defringing does tend to reduce edge acuity, leading to softer, lower-contrast edges in the corners.

Macro: The Canon S120 captured a smaller-than-average sized minimum area measuring 1.58 x 1.19 inches (40 x 30 millimeters). Detail is very good near the center, but corners are quite soft even at f/8 (most lenses show some softening in the corners at macro distances). The flash is partially blocked at closest distance, with the lens casting a large shadow in the lower right. Thus, you'll likely want to use external lighting for the closest S120 macro shots.

Canon S120 Viewfinder Accuracy

Viewfinder Accuracy: The Canon S120's LCD monitor shows just over 99% coverage at wide angle, and just over 100% at telephoto. Good results here, especially considering the amount of geometric distortion at wide angle.

The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Canon PowerShot S120 Photo Gallery .