Canon G3X Exposure

Saturation & Hue Accuracy
Fairly typical saturation levels with good hue accuracy.

Skin tones. With Auto white balance in simulated daylight, the Canon G3X rendered lighter Caucasian skin tones just a touch yellow and flat. Manual white balance produced more pleasant, pinkish skin tones. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.

Hue. The Canon PowerShot G3X produced a few color shifts relative to the correct mathematical translation of colors in its subjects, most visibly pushing cyan toward blue (probably for better-looking skies), red toward orange, and yellow toward green. Mean "delta-C" color error after correcting for saturation at base ISO was 4.57 which is bit better than average, and it remained better than average across the ISO range. Hue is "what color" the color is.

See full set of test images with explanations See thumbnails of all test and gallery images

Exposure and White Balance

Indoors, incandescent lighting
Strong color casts with Auto and Incandescent settings, but very good with Manual white balance setting. Average exposure accuracy.

Auto White Balance +0.3 EV	Incandescent White Balance +0.3 EV
Manual White Balance +0.3 EV

Color balance indoors under incandescent lighting was pretty awful with Auto white balance setting, with a strong red/magenta cast. The Incandescent white balance option was much too warm, with a strong yellow/orange cast. The Manual white balance setting was pretty accurate, though, but a touch cool. The PowerShot G3X's exposure system handled this lighting well, requiring a typical amount of exposure compensation (+ 0.3 EV) for this shot. Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.

Outdoors, daylight
Slightly cool colors, with high default contrast. Above average exposure compensation required.

Manual White Balance, +1.0 EV	Auto White Balance, Auto Exposure

The Canon PowerShot G3X performed fairly well in the simulated outdoor lighting of our "Sunlit" Portrait shot. Although above average exposure compensation of +1.0 EV was needed to keep the mannequin's facial skin tones bright, the number of blown highlights in her shirt and the flowers is actually not bad for a long zoom camera, and detail in the shadows is pretty good. The G3X underexposed our outdoor far-field shot a bit producing some very deep shadows, but as a result very few highlights were blown. Luminance noise is a bit high in deep shadows, however chrominance noise is well controlled. Color outdoors was good with the Auto white balance setting, just a touch cool, though the camera rendered skin tones a little too flat and yellow, so we preferred Manual white balance here for our "Sunlit" Portrait shot.

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
About 2,500 lines of strong detail from in-camera JPEGs, a little higher from converted RAW files.

In-camera JPEG: Strong detail to ~2,500 lines horizontal	In-camera JPEG: Strong detail to ~2,500 lines vertical
ACR converted RAW: Strong detail to ~2,600 lines horizontal	ACR converted RAW: Strong detail to ~2,500 lines vertical

Our laboratory resolution chart revealed sharp, distinct line patterns down to about 2,500 lines per picture height in the horizontal direction, and to about the same in the vertical direction in JPEGs straight out of the camera, though some minor aliasing in the form of moiré patterns could be seen as low as about 2,100 lines. Extinction of the pattern occurred just past 2,800 lines in the horizontal direction, and at about 3,000 lines in the vertical direction. Adobe Camera Raw was able to extract perhaps 100 extra lines of resolution in the horizontal direction but the vertical direction contained a lot of false colors past 2,500 lines so resolution didn't really improve in that direction. Total extinction of the pattern was extended to between 3,000 and 3,200 lines, though. Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Reasonably sharp, detailed images overall, though with some visible sharpening artifacts on high-contrast subjects. Noise suppression limits detail in low contrast areas.

Good definition of high-contrast elements, with some visible edge enhancement.	Subtle detail: Hair Noise suppression blurs detail in areas of subtle contrast, as in the darker parts of hair here.

Sharpness. The Canon PowerShot G3X captures reasonably sharp JPEG images at default settings, though some edge enhancement artifacts are visible on high-contrast subjects such as the noticeable halos around lines and text in the crop above left. Sharpening isn't as overdone as some cameras, but enthusiasts might want to shoot with a lower sharpening setting and apply additional sharpening in post processing, or shoot RAW for complete control over sharpening. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows some significant smudging of low contrast detail due to noise suppression, as individual strands of hair are blurred together in midtones and shadows, but performance here is still better than average for a long-zoom camera. Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.

RAW vs In-Camera JPEGs
As noted above the Canon G3X produces fairly sharp, detailed in-camera JPEGs at base ISO. But with a good RAW converter, more detail can often be extracted with fewer sharpening artifacts. See below:

In the table above, we compare an in-camera JPEG taken at base ISO using default noise reduction and sharpening (on the left) to the matching RAW file converted with Adobe Camera Raw 9.1 using default noise reduction with some strong but tight unsharp masking applied in Photoshop (400%, radius of 0.3 pixels, and a threshold of 0).

Looking closely at the images, ACR extracts additional detail that isn't present in the JPEG from the camera, particularly in the red-leaf swatch where the thread pattern is likely treated as noise by the JPEG engine. Fine detail in the mosaic crop is also slightly improved, but as is often the case, more noise can be seen in the bottle crop. You can of course apply stronger noise reduction (default ACR NR used here) to arrive at your ideal noise versus detail tradeoff. Color was improved as well, with ACR removing the slight yellow-to-green shift in the JPEG. And, as expected, sharpening haloes aren't nearly as strong as the default camera output. Still, in-camera default JPEG processing is pretty good at base ISO, but as usual you can do noticeably better with a good RAW converter.

ISO & Noise Performance
Good high ISO performance for a long-zoom camera.

Default Noise Reduction
ISO 125	ISO 200	ISO 400
ISO 800	ISO 1,600	ISO 3,200
ISO 6,400	ISO 12,800

ISO 125 and 200 images contain a lot of fine detail but are a little soft and a touch grainy when viewed at 100%, and ISO 400 already shows some significant smudging due to stronger noise reduction. ISO 800 is a little noisier and softer from more aggressive noise reduction, and ISO 1600 is softer still, however fine detail is still fair. Image quality drops off rapidly above ISO 1600, though, with increasing luma noise, noticeable chroma blotching as well as stronger blurring from noise reduction.

While high ISO performance is good for its class and much better than typical long-zoom cameras with smaller sensors, the G3X's JPEG engine does not appear to make the most of its larger, 1-inch type sensor producing somewhat soft, slightly grainy images already at moderate ISOs. Note that the G3X offers three levels of noise reduction (Low, Standard and High), and these shots were taken using the default Standard setting. Noise in the G3X's CR2 files is however competitive with other 1-inch sensor models, so for better high ISO performance, we recommend shooting in RAW format.

Of course, the impact of noise and detail loss are highly dependent on the size the photos are printed at, and pixel-peeping on-screen has surprisingly little relationship to how the images look when printed: See the Print Quality section below for recommended maximum print sizes at each ISO.

Note: We used to shoot this series at f/4 because of the relatively low light, but we now shoot it at f/5.6 for 1"-type sensors and f/8 for larger sensors, as fixed lens performance well away from center where we take the above crops is often not optimal at wider apertures. The added depth of field for a scene with this depth is also a better compromise than the potentially slightly sharper but shallower focus depth that a larger aperture would produce.

Extremes: Sunlit and low light tests
Pretty good dynamic range for its class. Very good low-light performance, capable of capturing bright images in near darkness.

+0.3 EV	+0.7 EV	+1.0 EV

Sunlight. The Canon PowerShot G3X did fairly well under the deliberately harsh lighting in the test above. To keep facial tones bright, +1.0 EV compensation was required, which led to some clipped highlights in the mannequin's shirt and flowers, but not as many as typical long-zoom cameras. Some may prefer the +0.7 EV setting for its reduced highlight clipping, but we found the face a bit too dim. Detail is quite good in the shadows at +1.0 EV, however very deep shadows are a little grainy and posterized, though chroma noise is well controlled. Very good results in harsh lighting for its class, but consider using fill flash in situations like the one shown above; and it's better to shoot in the shade when possible.

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here.)

Face Detection Examples
Aperture Priority Face Detect Off 0 EV	Aperture Priority Face Detect On 0 EV	Smart Auto 0 EV

Face Detection. The table above shows results with the default exposure using Aperture Priority AE with face detection Off and On, as well as Smart Auto. As you can see, the G3X's face detection and Smart Auto modes both increased exposure dramatically compared to the default exposure in Aperture Priority mode, going from very underexposed to bright images. Enabling face detection reduce the shutter speed from 1/80s to 1/40s to brighten the image, while Smart Auto selected a wider aperture of f/5 instead of f/8 we used in Aperture Priority, and boosted ISO to 250 as well.

Intelligent Contrast. As part of the G3X's Intelligent Contrast (i-Contrast) feature, the camera has "Dynamic Range Correction" to help tame highlights, and "Shadow Correct" to bring out more shadow detail.

Above are examples of our challenging "Sunlit" Portrait scene shot with the G3X's two available Dynamic Range Correction settings, plus Shadow Correct. Mouse over the links to the right to compare, and click on the links to get to the full-resolution images.

As you can see, highlights were toned-down with the DR 200% setting but results with DR Auto were practically identical to the Off setting, perhaps because relatively few highlights were blown to begin with. Shadow Correct also worked as expected, boosting shadows without impacting highlights too much, leading to the best overall exposure for this series.

Note that Dynamic Range Correction may boost ISO depending on your current setting, so more noise and/or stronger NR may be visible with it enabled. (In our samples above, DR 200% used ISO 250, while DR Auto and Shadow Correct left ISO at 125.)

Above, you can see the effect of the available i-Contrast settings on our Far-field shot. Here, DRC Auto and 200% both made a difference, but the effect was pretty subtle. Shadow Correct on the other hand made quite a difference, boosting midtones and shadows while maintaining highlights.

Dynamic Range Analysis (RAW mode)
While we once performed our own dynamic range measurements based on in-camera JPEGs as well as converted RAW images (when the camera was supported by Adobe Camera Raw), we've switched to using DxO Labs' results from their DxOMark website. As technology advanced, the dynamic range of modern high-end cameras in some cases exceeded the range of the Stouffer T4110 density scale that we used for our own measurements. DxO's approach based on RAW data before demosaicing is also more revealing, because it measures the fundamental dynamic range of the sensor, irrespective of whatever processing is applied to JPEGs, or to RAW data by off-the-shelf conversion software.

In the following, we use DxO's "Print" dynamic range results, which are scaled based on camera resolution. As the name suggests, this scaling corresponds to the situation in which you print at a given size, regardless of how many megapixels the camera might have. (In other words, if you've decided to make a 13x19 inch print, that's the size you're printing, whether the camera's resolution is 16 or 300 megapixels.) For the technically-minded, you can find a discussion of the reasoning behind this here on the DxOMark website. Also note that DxO Labs uses a signal-to-noise (SNR) threshold of 1 when defining the lower boundary of acceptable luminance noise in their dynamic range measurements, which corresponds to the "Low Quality" threshold of the Imatest software we used to use for this measurement.

Here, we decided to compare the Canon G3X's dynamic range to two competing enthusiast long zooms, the Sony RX10 II and the Panasonic FZ1000. You can always compare to other models on DxOMark.com.

As you can see from the above graph (click for a larger image), the G3X has dynamic range performance that is very similar to the RX10 II's. The Sony does however do a little better at base ISO since it offers a native ISO 100 setting whereas the G3X's lowest (and cleanest) sensitivity setting is ISO 125. The G3X's maximum dynamic range is 12.3 EV at base ISO, with a minimum of 6.2 EV at the top ISO. The Sony offers a range of 12.6 EV down to about 6.8 EV at the highest ISO, but notice that according to DxO the Sony applies some minor noise reduction to its files at ISO 6400 and 12,800, as indicated by the "smoothed" data points.

The Canon G3X offers better dynamic range than the Panasonic FZ1000 at both lower and higher ISOs, but about the same at ISO 800. At its lowest ISO, the FZ1000 scored 11.74 EV versus the G3X's 12.25 EV despite the lower ISO 80 setting offered by the Panasonic, which is just over a 0.5 EV advantage for the Canon. At ISO 12,800, the Canon again does better at 6.23 vs 5.5, a significant difference.

Overall, excellent dynamic range for a 1"-type sensor from the G3X. Click here to visit the DxOMark page for the Canon G3X for more of their test results and additional comparisons.

	1 fc 11 lux	1/16 fc 0.67 lux	1/16 fc No NR
ISO 125	1.6s, f2.8	1.6s, f2.8	25s, f2.8
ISO 3200	1/16s, f2.8	1.0s, f2.8	1.0s, f2.8
ISO 12800	1/64s, f2.8	1/4s, f2.8	1/4s, f2.8

Low Light. The Canon PowerShot G3X performed very well in our low-light tests, capturing bright images at the lowest light level (1/16 foot-candle), even at the lowest sensitivity setting (ISO 125). As expected for a 1"-type sensor, luma noise is a little high at ISO 3200, but fairly fine-grained, while chroma noise is well controlled. The G3X's highest ISO of 12,800 is quite grainy with strong blurring, but that's no surprise.

Color balance is pretty good with Canon G3X's Auto white balance setting, just a touch cool, even at highest ISO and lowest light level. We didn't notice any significant issues with pattern noise or heat blooming. We noticed a few hot pixels at base ISO, especially with long exposure noise reduction disabled (right-most column), though that's not unusual.

The camera's AF system was able to focus unassisted to just below the 1/8 foot-candle light level in our tests at wide angle (f/2.8), which is very good, though it can struggle to focus at dimmer telephoto focal lengths. And the G3X was able to focus in complete darkness with the aid of its AF assist lamp.

How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) For such applications, you may have better luck with a digital SLR camera, but even there, you'll likely need to set the focus manually. For information and reviews on digital SLRs, refer to our SLR review index page.

Print Quality
Good prints up to 20 x 30 inches at ISO 125 and 200; Nice 11 x 14 inch prints at ISO 1600; and 4 x 6 inch prints just pass the mark at ISO 6400.

ISO 125/200 images display a lot of fine detail and pleasing colors to 20 x 30 inches. Bumping up to 24 x 36 is really hitting the limits of the camera's sensor, but those sizes could be used for wall display.

ISO 400 prints show a slight drop in crisp, fine detail compared to lower ISOs, making a 16 x 20 inch print the largest size we're comfortable calling at this sensitivity. Detail and colors are still nice overall and noise is well controlled.

ISO 800 images top out at 13 x 19 inch prints, as noise-related softening is becoming apparent. Noise reduction processing, on the other hand, does well to keep visible noise and grain at bay.

ISO 1600 prints, as expected, are a bit softer than the previous ISO level and look nice up to 11 x 14 inches. Noise itself is still fairly well controlled, though some particular areas -- like our often-tricky red-leaf fabric -- are quite soft and lacking fine detail. Higher contrast detail, however, still looks nice.

ISO 3200 images definitely display noise-related softening throughout. NR processing is handling grain quite well, but an overall increase in softness makes printing larger than an 8 x 10 tricky.

ISO 6400 prints show acceptable detail up to 4 x 6 inches. Any larger and the softness simply does not look that pleasing at this sensitivity. That being said, a 5 x 7 inch print could be used for less critical applications.

ISO 12,800 images are simply too soft and display visible false colorations to make an acceptable print at any size.

Sharing the same 20-megapixel 1-inch-type sensor as the pocketable G7X, it's no surprise that its big-lensed brother does just as well in the print department. The Canon G3X does a good job at lower ISOs and pushes the sensor resolution to the max with nice 20 x 30 inch prints around base ISO. Toward the mid-range ISOs, images begin to soften, but in-camera NR does well to hold off unsightly noise and coarse grain. At ISO 1600, for example, prints still look pleasing up to 11 x 14 inches. At the very high end of the ISO scale, the G3X still manages an acceptable 4 x 6 at ISO 6400. However, printing at its maximum ISO 12,800 should be avoided.