Zoom
Pretty good performance with the camera's 3.7x optical zoom lens, and good results with digital zoom as well.

36mm	133mm	4x Digital Zoom

The Canon PowerShot SD950 IS' optical zoom covers the equivalent of a 36-133mm, just a hair larger range than that of the typical consumer digital camera. At wide angle, details are sharp and clear throughout most of the frame, though there's a fair amount of blurring in the corners and a small amount of coma distortion at the top of the frame. (Results aren't what I would consider bad.) Results at full telephoto are quite good. The camera's 4x digital zoom turns in fairly soft images. Though resolution is decreased and more artifacts are visible, performance is actually a little better than average, especially considering the file size.

Macro
An average macro area, though very good detail and resolution. Flash produces a very uneven exposure.

Standard Macro	Macro with Flash

The Canon PowerShot SD950 IS' macro setting performed about average, capturing a minimum area of 2.07 x 1.55 inches (53 x 39 millimeters). Detail and resolution are both excellent, though, with only a moderate amount of softening in the corners from the lens. (Most cameras have some softening in the corners in macro mode.) Exposure is a little dim with the artificial lighting, but still passable. The SD950 IS' flash almost got it right, though there's a stark shadow from the lens in the lower right corner and a hot spot at the top left of the frame. (Plan on using external lighting for important macro shots with the SD950 IS.) It's actually a pretty darn impressive performance from a pocket digital camera, especially considering the 12.1-megapixel resolution.

Distortion
Moderate barrel distortion, though virtually no pincushion.

Barrel distortion at 36mm is 0.8%

Pincushion at 133mm is unmeasurable

The Canon PowerShot SD950 IS' 0.8% barrel distortion at wide angle is on the high side of average, and fairly noticeable in some images. At the telephoto end, I couldn't find a pixel of either pincushion or barrel distortion.

This is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide angle) or inward (like a pincushion -- usually at telephoto).

Chromatic aberration
High but dim at wide angle, intensified by blurring in the corners.

Wide: High and dim, top left @ 200%	Wide: High, top right @ 200%
Tele: High but less bright top left @200%	Tele: High, top right @200%

Chromatic aberration is high at wide angle, showing about 20+ pixels of coloration on either side of the target lines. However, blurring is also noticeable here, which is intensifying the effect. At telephoto, the distortion is again high, though this time pixels are mainly on the inside of the lines rather than on both sides. (This distortion is visible as a slight colored fringe around the objects at the edges of the field of view on the resolution target.)

Corner Sharpness
Strong blurring in the corners of the frame at wide angle, and a moderate amount at telephoto.

Wide: Very soft in the corners (upper left).	Wide: Sharp at center.
Tele: Softer in the corners (upper left)	Tele: Sharp at center.

The Canon PowerShot SD950 IS produced very soft corners of the frame at full wide angle, which was quite noticeable in its images. The stronger blurring also intensified chromatic aberration, as shown in the images above these. At full telephoto, blurring was less strong, and only slightly noticeable.

Coverage
Poor performance with the optical viewfinder, but very good results with the LCD monitor.

36mm eq., Optical	133mm eq., Optical
36mm eq., LCD	133mm eq., LCD

The Canon PowerShot SD950 IS' optical viewfinder was quite inaccurate, and our tester noted that it was very difficult to line up shots, as the viewfinder appeared to be pointing off in an odd direction. Once he did get the framing about right however, we measured its accuracy at about 83% at wide angle, and about 82% at telephoto. In contrast, the camera's LCD monitor turned in a much better performance, measuring about 103% at wide angle and about 101% at telephoto. Slightly loose, but still very good.