Canon G10 Optics

Zoom
A fairly wide, 5x optical zoom lens with good performance. Average digital zoom performance.

The Canon PowerShot G10's lens covers the equivalent of a 28-140mm zoom on a 35mm camera, which is slightly more zoom ratio than most consumer digital cameras. While the 5x zoom ratio has dropped compared to the 6x zoom on the G9, we welcome the gain at the wide-angle end, even at the cost of losing some telephoto reach in the bargain. Results are quite good at wide-angle, with minimal blurring and coma distortion., though some chromatic aberration can be seen in the corners and edges, and some minor flare is noticeable around the brighter areas of the scene. Details are a bit softer at full telephoto, but with only a small amount of chromatic aberration and flare. The camera's 4x digital zoom did a good job of maintaining fine detail despite the typical blurring and loss of resolution associated with digital zoom.

Macro
A very small macro area, with excellent detail and resolution. Flash is blocked by lens.

The Canon PowerShot G10's macro setting captured a very tiny minimum area of just 1.18 x 0.89 inches (30 x 23 millimeters). Exposure is a bit uneven, due to the very close shooting range, and the three dimensional structure of the target (the brooch and one of the coins are shading the dollar bill). Detail and resolution were both excellent, particularly in the center of the frame. There's quite a lot of softening in the corners from the lens, as well as some chromatic aberration. (Most cameras have some softening in the corners in macro mode, but this is extreme.) The G10's flash throttled down for the macro area fairly well, but the exposure was again quite uneven, as the flash is blocked by the lens when this close. Plan on using external lighting for the very closest macro shots with the G10, and even then, you may have trouble getting the light in onto your subject given how close the G10 focuses. All in all, a very good performance.

Distortion
Higher than average barrel distortion at wide angle, very low pincushion at telephoto.

The Canon G10's 0.9% barrel distortion at wide angle is higher than average, but that's not surprising considering its 28mm equivalent focal length. Still, we'd like to see lower, as the distortion is quite noticeable in some of its images. At the telephoto end, the G10's less than 0.1% pincushion distortion is almost nonexistent. 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
Moderately bright at wide-angle, almost none at telephoto.

Chromatic aberration is moderate at wide angle, showing about 6-8 pixels of moderately bright coloration on either side of the target lines. At telephoto, chromatic aberration is not nearly as bright and much less noticeable. Chromatic aberration is a type of distortion visible as a slight colored fringe around the objects at the edges of the field of view on the resolution target.

Corner Sharpness
Moderate blurring in the corners of the frame at wide angle and telephoto.

The Canon PowerShot G10's lens produced some soft corners at full wide angle and telephoto. Blurring was strongest in the upper left corner, for both wide angle and telephoto. The center was a bit soft at full telephoto as well.

Coverage
An inaccurate optical viewfinder, but very good accuracy from the LCD monitor.

The Canon PowerShot G10's optical viewfinder was very tight, at around 82% coverage at wide angle, and 79% at telephoto. It's also somewhat tilted and offset with respect to the CCD. This is not unusual for this type of optical viewfinder though. The LCD monitor was much more accurate, showing about 101% coverage accuracy at wide angle, and about 100% at telephoto.