Canon G1X Mark II Optics

Zoom
Generally good optical performance from the wide-angle 5x optical zoom.

The Canon PowerShot G1 X II's 5x zoom lens covers the equivalent of about 24-120mm on a 35mm camera, compared to 28-112mm (4x zoom) for the G1X. Maximum aperture has improved as well, ranging from f/2.0 at wide-angle to f/3.9 at telephoto versus f/2.8-5.8, though it does fall off rapidly as you zoom.

The following table reflects the maximum and minimum apertures as reported by the camera:

Sharpness is very good across most of the frame at full wide-angle and f/8, with just minor softness in the corners. Very little chromatic aberration is visible (effectively suppressed by the DIGIC 6 processor), though some minor flare is evident around the bright white elements of this shot. At medium focal length (~53mm eq.), sharpness and contrast are very good across the frame at f/8, and flare doesn't appear to be an issue. Results at full telephoto and f/8 are also very good, with very good sharpness and contrast across the frame. Again, chromatic aberration is negligible because the G1 X II suppresses it in JPEGs.

The G1 X Mark II also offers digital zoom up to 4x, and what Canon calls a "digital teleconverter" at preset magnifications of 1.6x and 2.0x. Digital teleconverter at 2.0x (shown above) does a better than average job because of lower noise levels compared to most digicams, though we wouldn't recommend using higher digital zoom magnifications due to the loss of fine detail that usually comes with strong digital enlargement.

Overall, good to very good far-field performance at f/8.

Macro
A larger than average macro area, with very good detail. Flash is partially blocked by the lens.

The Canon PowerShot G1 X II's lens captured a larger-than-average minimum area of 3.07 x 2.30 inches (78 x 59 millimeters), though that's much improved over the G1 X's minimum macro area (8.79 x 6.59 in. or 223 x 167 mm). Sharpness is pretty good over much of the frame, though extreme corners are quite soft from field curvature of the lens. (Most cameras have some softening in the corners in macro mode. What we see here is better than average.) The Canon G1 X II's built-in flash is partially block by the lens at closest focus distance, resulting in a very dark shadow in the bottom right and overexposure in the top left. You'll likely want to use external lighting for close macro shots with the G1 X II.

Distortion
Lower than average barrel distortion in JPEGs; very high at wide angle in uncorrected RAW files.

JPEG: The Canon G1 X II's just under 0.1% complex pincushion distortion at wide angle is very low compared to the average digital camera, especially considering its generously wide 24mm-equivalent focal length (see below for the explanation). The ~0.1% complex barrel distortion at the telephoto end is also very low and not the pincushion type of distortion we normally see at telephoto. 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).

RAW: When converting RAW files using dcraw (no corrections applied), barrel distortion at wide-angle is very high, at about 4.4%. Also note how the image "circle" does not cover a significant portion of the sensor (it seems to be masked, perhaps to help reduce internal reflections). Distortion at full telephoto is about the same as the in-camera JPEG, so no correction is performed by the camera at the telephoto end. Canon's bundled Digital Photo Professional and Adobe Camera Raw automatically reduce geometric distortion, producing distortion results similar to in-camera JPEGs, though ACR crops away more than the camera.

We expect high distortion at wide angle for smaller lenses though, and most RAW converters will automatically correct for it. There is however going to be a loss of resolution as well as possible interpolation artifacts as a result of such strong correction, because pixels in the corners of the frame are being "stretched" to correct for the distortion. If you look closely at the corners in the G1 X II's wide-angle shots, they are soft and detail is a little rough with normally straight edges in the resolution target looking jagged. Obviously, a lens that doesn't require such correction and is also sharp in the corners to begin with would be preferable, but relaxing constraints on distortion brings other benefits in the lens design, such as a compact, lower cost design.

Chromatic Aberration and Corner Softness
CA is low at wide-angle, and even lower at telephoto in JPEGs. Mild to moderate blurring in the corners of the frame at wide angle, but very good corner sharpness at full telephoto.

Chromatic Aberration. Chromatic aberration is quite low at both wide angle and full telephoto, because the G1 X II's DIGIC 6 processor removes most of it. See below for examples of uncorrected C.A. 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 Softness. The Canon G1 X II's lens produces moderately soft corners at full wide angle when wide open. Blurring is about the same in all for corners, but softness doesn't extend very far into the frame though there is some loss of definition, but the center is quite sharp. Much of the softness is due to the strong geometric distortion and CA correction taking place at wide angle. Corners at full telephoto are fairly sharp but not quite as contrasty as the center. Vignetting is not a problem at either end of the zoom.

When the lens is stopped-down to f/5.6, corner sharpness improves at wide angle, though you can still see some softness and rough edges due to the strong distortion correction applied. At full telephoto, corner sharpness remains about the same which is to say very good but with improved contrast, almost as sharp as the center.

Chromatic Aberration Correction

As you can see, the Canon G1 X II's DIGIC 6 processor does a great job suppressing most of the chromatic aberration in JPEGs (crops on the left) versus RAW files converted in Adobe Camera Raw (on the right), which appears not to correct for CA by default. Not surprisingly, C.A. is much stronger at wide angle compared to telephoto.

We found when taking shots wide open at maximum aperture, the G1 X Mark II's lens can produce what looks like localized flare that can also be described as a glowing softness or a halo effect, likely caused by poorly corrected spherical aberration and sometimes accompanied by axial chromatic aberration. The defect is most noticeable in high-contrast subjects that are slightly outside the plane of sharp focus, and diminishes when you stop down, as you can see by the difference between f/2 and f/2.8 in the top set of crops above. The aberration appears to be worst case at wide angle and closest focus, however, we have also seen it in shots at more normal subject distances, and at other focal lengths as seen in the second set of crops above taken at about 7 feet and approximately 100mm equivalent (those crops show an area behind the plane of focus). You'll likely want to stop down as much as you can for most macros to maximize depth of field, but since it can still occur in non-macro shots, you may want to stop down a click or two to avoid this effect, particularly for high-contrast or bright subjects that have some depth to them. Of course, having to stop down unfortunately negates the value of a fast lens in some circumstances.

Coverage
Excellent accuracy from the LCD monitor and optional EVF.

The Canon PowerShot G1 X II's LCD monitor and optional EVF-DC1 electronic viewfinder displayed excellent accuracy, both showing essentially 100% coverage at wide angle, and slightly over 100% at full telephoto.