Canon G9 Optics

Zoom
An impressive 6x optical zoom lens with great performance. Digital zoom also performs well.

The Canon PowerShot G9's optical zoom covers the equivalent of a 35-210mm, a much larger range than the average consumer digital camera. Details are sharp and well-defined at full wide angle, with low levels of coma distortion and very good corner-to-corner sharpness. Results at full telephoto are also quite good. Though the PowerShot G9 does sacrifice detail definition and resolution with its 4x digital zoom, results are actually much better than average. An excellent performance overall.

Macro
A very small macro area with good detail and high resolution. Flash performs well also.

The Canon PowerShot G9's macro setting performed quite well, capturing a very small minimum area of 1.00 x 0.75 inches (26 x 19 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 along the left side of the frame. (Most cameras have some softening in the corners in macro mode.) The G9's flash throttled down for the macro area fairly well, but the exposure was again quite uneven. Plan on using external lighting for the very closest macro shots with the G9, and even then, you may have trouble getting the light in onto your subject given how close the G9 focuses. All in all, a very good performance, better than most cameras out there.

Distortion
Moderate barrel distortion, though low pincushion.

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). The Canon PowerShot G9's 0.8% barrel distortion at wide angle is about average, though we think this level is too high, as it can be quite evident in photos. At the telephoto end, the G9's 0.2% pincushion distortion is reasonably low, if not the lowest we've seen.

Chromatic aberration
High and bright at wide angle, lower at telephoto. More than we'd like overall, noticeable in some of our images at wide angle.

Chromatic aberration is fairly high at wide angle, showing about 10-12 pixels of bright coloration on either side of the target lines, and it extends fairly far into the frame. At telephoto, the effect isn't quite as strong, and pixels not nearly as bright. (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
Excellent corner to corner sharpness, with only minimal blurring visible, and only in one or two corners at both zoom settings.

The Canon PowerShot G9 produced excellent corner-to-corner sharpness at both wide angle and telephoto zoom settings. At both settings, blurring was minimal, and only appeared in one or two corners of the frame. Excellent performance here. (But the colored ghosts from chromatic aberration are clearly visible, particularly at wide angle.)

Coverage
A tight optical viewfinder, but accurate LCD monitor.

The Canon PowerShot G9's optical viewfinder proved very tight in its framing, showing only 82% of the final image area at both wide angle and telephoto. Our lab tech noted that the optical viewfinder was quite hard to frame with, seeming to point in a completely different direction than the lens. (You can clearly see this in the images above, the final image is quite a bit off-center to the top from where the camera was aimed through the viewfinder.) However, the LCD monitor proved much more accurate, showing about 103% at wide angle, and about 99% at telephoto. (The 103% at wide angle is likely just a reflection of the barrel distortion, which makes it hard to choose what to call "properly framed" when looking at the image. - The question becomes: do you pay more attention to the framing at the corners of the frame or the middle of each side?)