Canon Powershot G3 X Review

Ultimately, a camera is only as good as the photographs it produces. For this reason, ratings in our digital camera reviews is based primarily on image-quality. The Canon Powershot G3 X is one of only two ultra-zooms to feature a moderately large 1" sensor which is highly beneficial. The 20 megapixels 1" CMOS sensor in this camera has roughly 4X the area of those found in nearly every other ultra-zoom. This gives it significantly larger pixels than most of its peers, despite a having such a high resolution.

The baseline ISO 125 sensitivity shows really low image-noise and usable for very large prints. ISO 200 performs almost identically with only slightly more noise visible at 100%. ISO 400 is surprisingly smooth as it shows the first signs of noise-reduction. Given 20 megapixels of resolution, this will not have much of an impact unless printed quite large.

An increase in noise levels is easily apparent at ISO 800 with a slight impact on fine-details. Noise-reduction is visible but still very gentle. There is no problem getting a reasonably-large high-quality print at this sensitivity. ISO 1600 shows a little more noise with damage to fine-details. Maximum prints sizes are reduced slightly, yet common sizes still look great.

Noise-reduction is much more noticeable at ISO 3200. Entire images taken on a soft look with little noise and relatively good contrast. Mid-sized prints are no issue but dynamic-range starts to drop visibly at that point. Colors though seem to be well maintained even up to this ISO.

There is a veil of noise at ISO 6400 with strong softness due to noise-reduction and a sharp drop in contrast. Even with that much processing, noise remains very present at ISO 6400. One can manage decent small prints or images for web use. ISO 12800 is devoid of details, noisy and has limited contrast. That sensitivity is best avoided.

The dynamic-range of the Canon Powershot G3 X is surprisingly good. It certainly exceeds what most fixed-lens cameras can do. When highlights get clipped, it gives a natural bloom with a relatively smooth cut-off. Shadows look natural with deep blacks until ISO 800. The default contrast setting is spot-on for this but can be adjusted to taste ±2 steps.

The Multi-Segment metering system is generally reliable and consistent. It is tuned for mid-tone exposures, so it regularly clips small highlights and makes high-key scenes overly dark. It rarely misses by much though, 1/3 or 2/3 EV being typical.

Sharpness is just right at the default setting. Artifacts start showing at +1 and noticeable softness appears at -1. One can always perform their own processing by shooting RAW files instead of JPEG. The main limitation on this Powershot is that there is no buffer for shooting RAW files continuously.

Canon has very well tuned colors to look pleasing on the G3 X. This is made clear by the fact that image parameters are hidden under the Custom option when My Colors are enabled. There, one can improve accuracy slightly by tuning Red and Blue down to -1. Otherwise, they are slightly oversaturated. Automatic White-Balance could fair better. While it generally produces neutral colors, it misses more often under artificial-light, often leaving a yellowish cast.

The Canon Powershot G3 X has the longest zoom of any large-sensor camera. At 25X, it covers an equivalent 24-600mm focal-range with a maximum F/2.8-5.6 aperture. While this is specification is common on standard ultra-zooms, it is quite an achievement for a 1" sensor. The lens shows no signs of chromatic aberrations or vignetting at any aperture or focal-length which is very impressive.

Sharpness is the center is superb. Near wide angle though, there is severe edge softness which is easily notable until one third of the way to the image-center. It improves considerable when stopped down to F/5.6, achieving really good definition from F/6.3 to F/8 before diffraction kicks-in already at F/10. At medium focal-lengths, there is still softness roughly one third to the center but it is somewhat less pronounced than at wide-angle. Again, F/5.6 is notably better and, by F/7.1, there is good sharpness across the frame.

The lens on the G3 X performs best at long focal-lengths. There, the maximum F/5.6 aperture only shows slight edge softness about one sixth of the way into the frame. Stopping down to F/8 provides very good overall sharpness. Basically, from F/5.6 at any focal-length, results are quite usable. This unfortunately leaves a narrow range of optimal apertures from F/6.3 to F/9. Clearly, they had to compromise here in order to build such a powerful optical zoom for a large-sensor digital camera.

The Canon G3 X is generally responsive. Every button and dial turn gets an instant response with good visual feedback from the camera. The performance of this digital camera is characterized by the following numbers:

• Power-On: 1½s. Good.
• Power-On to First-Shot: Just over 2s. Slightly better than average.
• Autofocus: ½-1s. Somewhat slower than average, particularly at long focal-lengths.
• Shutter-Lag: Instant with 1/3s blackout. Excellent.
• Shot-to-Shot: Almost 1¼s with or without AF. Average.
• Zooming: 2½s, wide-to-tele. Average.
• Playback: 1s to enter or exist. Slower than average.
• Power-Off: 2-3½s, depending on zoom. Average.

In short, the Canon Powershot G3 X offers an average performance for a prosumer digital camera. One remaining performance metric is battery-life which is quoted at 300 shots-per-charge according to the CIPA standard. This is below average for an ultra-zoom and a second battery would be highly recommended for a full day of shooting.

The Canon Powershot G3 X packs the most powerful lens fixed to a large-sensor digital camera. Its 20 megapixels 1" CMOS sensor combines with a 25X optical zoom lens to deliver high image-quality and versatility in a sturdy weather-sealed body which makes this an ideal all-in-one camera for travel photography.

The sensor in the G3 X unsurprisingly delivers high image-quality, similar to the compact G7 X previously reviewed here. While the processing engine has been tweaked, the G3 X produces images with low-noise, plenty of fine details, good dynamic-range and pleasing colors. Metering is well balanced, as is automatic white-balance. Either can be adjusted when they miss which is rarely by much.

One can marvel at the stabilized 24-600mm F/2.8-5.6 lens on this ultra-zoom but this is where the compromise lies. Images are very sharp in the center while showing strong edge softness until stopped down to F/5.6 at the wide-end and a little further towards telephoto. This lens shows no signs of vignetting or chromatic aberrations which is excellent.

Speed is where the Canon G3 X simply matches expectations. It remains responsive at all times with average performance for most operations. Shutter-lag is excellent with minimal black out, while autofocus is slightly slow when zoomed in due to the dim maximum aperture. The weatherproof body seems quite sturdy except for the top LCD hinges. It is clearly not freezeproof and nearly impossible to use with gloves on since most buttons and dials are flush with the surface.

The Canon G3 X really provides a unique mix image-quality and optics. Its ultra-wide to super-telephoto focal-range is unmatched by any large-sensor camera and makes it among the most versatile, capable of capturing most subjects, from landscapes to wildlife.