Canon G7X II Image Quality


Color

Saturation & Hue Accuracy
Slightly below average mean saturation levels with excellent hue accuracy.

In the diagram above, the squares show the original color, and the circles show the color that the camera captured. More saturated colors are located towards the periphery of the graph. Hue changes as you travel around the center. Thus, hue-accurate, highly saturated colors appear as lines radiating from the center. Click chart for a larger image.

Saturation. The Canon G7X II produced realistic saturation levels, with only mild boosts to most colors and moderate oversaturation of reds. Greens and blues are not boosted as much as its predecessor, while bright yellow, light green, aqua and cyan were undersaturated by small amounts. Mean saturation at base ISO is 106.2%, or 6.2% oversaturated, which is a little below average these days. Overall, the Canon G7X II's images still appear to have pleasing saturation levels and you can always adjust saturation using the camera's "My Colors" options. Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life.

Skin tones. With Manual white balance in simulated daylight, the Canon G7X II rendered lighter Caucasian skin tones just a touch too yellow. Auto 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 G7X II produced a few color shifts relative to the ideal hues with Manual white balance in simulated daylight, most visibly pushing cyan toward blue (probably for better-looking skies), orange to yellow, and yellow toward green, but all shifts were quite minor. Mean "delta-C" color error after correcting for saturation at base ISO was only 3.49 which is excellent and much better than average, with hardly any yellow-to-green shift we often see. Hue is "what color" the color is.

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

Sensor

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, producing a strong red/magenta cast. The Incandescent white balance option was better, but too warm, with a strong yellow/orange cast. The Manual white balance setting was pretty accurate, though, but a touch cool. The PowerShot G7X II'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.

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

The Canon PowerShot G7X II 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 such a compact camera, and detail in the shadows is pretty good. The G7X II underexposed our outdoor far-field shot at default exposure 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, and Auto WB produced more pinkish, healthy-looking skin tones than Manual WB did for our "Sunlit" Portrait shot.

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

Resolution
~2,600 lines of strong detail from in-camera JPEGs, about the same from converted RAW files.

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

Our laboratory resolution chart revealed sharp, distinct line patterns up to about 2,600 lines per picture height in the horizontal direction, and to about the same in the vertical direction in JPEGs straight out of the camera, although some aliasing artifacts can be seen as early as 1,300 lines. Extinction of the pattern occurred at around 3,000 lines in the horizontal direction, and at around 3,200 lines in the vertical direction. An Adobe Camera Raw conversion of the matching CR2 file didn't really produce higher resolution numbers, however total extinction of the pattern was extended to between 3,200 and 3,400 lines, with obvious false colors past the resolution limits. 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
Fairly 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 G7X II captures fairly 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 appears a little higher than its predecessor which give G7X II images a bit more "pop" straight out of the camera, but enthusiasts might want to shoot with a lower sharpening setting and apply additional sharpening in post processing, try the new Fine Detail mode (see below), 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 at base ISO, as individual strands of hair are blurred together in midtones and shadows, but noise is quite low as a result while still holding onto a decent amount of detail. 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.

In-Camera JPEGs: Standard vs Fine Detail Picture Style setting
The Canon G7X II is the first PowerShot to offer the Fine Detail Picture Style first seen on the Canon EOS 5DSR/5DS and then on the 80D. Below is a comparison with the default Standard Picture Style.

Base ISO (125)
Camera JPEG, defaults
Camera JPEG, Fine Detail

In the table above, we compare the Canon G7X II's default Standard Picture Style setting (left) to its new Fine Detail preset at base ISO. Like the Canon EOS 5DS/R and 80D DSLRs, the Canon G7X II offers users much more flexibility in sharpening than other PowerShot models, allowing you to adjust not only the "Strength" (from 0 to 7) but also the "Fineness" (1 to 5) and "Threshold" (1 to 5) operators. We believe these parameters correlate to unsharp mask options for strength, radius and threshold available in photo editing software such as Photoshop, although we don't know what the equivalent units might be.

The result is a slightly improved, more natural-looking rendering of fine detail along with slightly less obvious sharpening halos than the default Standard setting. However, noise is more visible in flatter areas, and contrast is lower, making the Fine Detail image appear to have less "pop" than the default Picture Style. There also appear to be minor differences in color, even though Color Tone, Saturation and Contrast settings are identical between these two Picture Styles presets. Given the flexibility in settings, though, you may be able to find a better combination than the defaults compared above.

RAW vs Default In-Camera JPEGs
As noted above the Canon G7X II 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:

Base ISO (125)
Camera JPEG, defaults
RAW via Adobe Camera Raw

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 via DNG Converter 9.6 using default noise reduction with some strong but tight unsharp masking applied in Photoshop (300%, radius of 0.3 pixels, and a threshold of 0).

Looking closely at the images, it's clear that 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 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. As expected, sharpening halos aren't nearly as strong as the default camera output but the conversion doesn't have the same "pop" as the in-camera JPEG because of lower contrast, and we actually prefer Canon's colors. Still, as usual, you can produce finer detail with a good RAW converter, as well as have more control over noise reduction, color, saturation, contrast, etc.

ISO & Noise Performance
Very good high ISO performance for a camera its size.

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

The PowerShot G7X II performed very well here for its size, with improved color and crispness compared to its predecessor at low to moderate ISOs. ISO 125 and 200 are quite clean and detailed with much better crispness than our G7X's indoor portrait shots. ISO 400 shows some softening due to stronger noise reduction, but detail and clarity in the hair are noticeably better than from the G7X. ISO 800 is noisier and softer from more aggressive noise reduction however it's still better than the G7X's image. ISO 1600 is of course softer but still better than the G7X's, and this is true of ISO 3200 as well. Image quality drops off rapidly at ISO 6400 and 12,800, though, with strong luma noise as well as strong blurring from noise reduction, no longer giving the G7X II an edge over the G7X except in color.

Overall, noticeably improved JPEG image quality at low to moderately high ISOs compared to the G7X, at least here under incandescent lighting.

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.

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

+0.3 EV +0.7 EV +1.0 EV

Sunlight. The Canon PowerShot G7X II did 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 one might expect, and they are easily recoverable from the RAW files. 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, though very deep shadows are a little grainy and discolored, however chroma noise is well controlled. Very good results in harsh lighting for such a compact camera, 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
0 EV
Face Detection
0 EV
Smart Auto
0 EV

The table above shows results with the default exposure using Aperture Priority AE, as well as with face detection enabled, and Smart Auto mode. As you can see, the G7X II'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. Smart Auto mode selected an aperture of f/3.5 instead of f/4 we used in Aperture Priority and reduced ISO slightly to at 116 according to EXIF.

Highlights and Shadows
Previous PowerShot models offered an Intelligent Contrast (i-Contrast) feature, with "Dynamic Range Correction" to help tame highlights, and "Shadow Correct" to bring out more shadow detail, however the G7X II is the first PowerShot to implement Highlight Tone Priority as well as Automatic Lighting Optimization, just like Canon's EOS models.

Highlight Tone Priority
While very few highlights were blown to begin with at default exposure, below you can see the Canon G7X II's Highlight Tone Priority (HTP) option still toned down highlights while essentially leaving shadows and midtones alone. (Mouse over the Off and On links to load the corresponding thumbnail, histogram and crops.)

Highlight Tone Priority (0 EV)
HTP
Setting:



Off


On

Highlights
Shadows
(Levels boosted
to reveal noise.)
Histogram

Both shots above were captured at the same exposure, the only difference being that HTP was enabled for the second shot which necessarily increases the minimum ISO to 250; part of how HTP works. If you look closely at shadows (the levels in shadow crops above are heavily boosted to reveal noise that would be difficult to see otherwise), you'll notice an increase in noise is the price you pay when ISO is boosted (here, from 125 to 250).

Auto Lighting Optimizer
Like Canon EOS models, the G7X II offers three selectable levels of Automatic Lighting Optimization (ALO), plus Off. In fully automatic mode (Smart Auto or Hybrid Auto) and some scene modes, ALO is automatically enabled and it's available in P, Tv, Av and M exposure modes. Mouse over the links below to load the associated thumbnail and histogram, and click on the links to load full resolution images.

Automatic Lighting Optimizer (0 EV)

As you can see above, ALO has the effect of shifting shadows and darker mid-tones in the histograms to the right, brightening shadows and indeed most of the image without affecting highlights much. ISO is not boosted for ALO so increased noise is not an issue, though it may be slightly more visible in shadows that have been boosted significantly.

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.

Unfortunately, DxOMark has not tested the G7X II at the time of writing. We'll come back and fill this section in after they do, but in the meantime, check out their G7X test results which should be very similar.


  1 fc
11 lux
1/16 fc
0.67 lux
1/16 fc
No NR
ISO
125

0.5s, f1.8

8s, f1.8

8s, f1.8
ISO
3200

1/50s, f1.8

0.3s, f1.8

0.3s, f1.8
ISO
12800

1/200s, f1.8

1/13s, f1.8

1/13s, f1.8

Low Light. The Canon PowerShot G7X II performed very well in our low-light tests thanks to its fast lens, 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 very well-controlled. The G7X II's highest ISO of 12,800 is quite grainy with strong blurring, but that's no surprise.

Color balance is pretty good with Canon G7X II'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 hot pixels, pattern noise or heat blooming.

LL AF: The camera's AF system was able to focus unassisted on our low-contrast AF target down to -3.8 EV at wide angle, and on our high-contrast AF target down to -6.4 EV, which is excellent. And the G7X II was able to focus on both targets 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.

Output Quality

Print Quality
Excellent, high-resolution prints up to 24 x 36 inches at ISO 125-200; Nice 8 x 10 inch prints at ISO 3200; and usable 5 x 7 inch prints at ISO 6400.

ISO 125/200 images look great all the way up to 24 x 36 inches. At this print size, you're pushing the limits of the 20MP sensor, but from a typical viewing distance for a print this large, image quality is impressive. There's a lot of crisp fine detail and pleasing, vibrant colors. ISO 200 images look practically identical to base ISO ones, especially in prints, with no visible increase in noise or decrease in detail that would impact print sizes.

ISO 400 prints start to display a slight drop in fine detail and a bit of visible noise back in the shadow areas. Therefore, we're putting the print size limit at a still-healthy 20 x 30 inches.

ISO 800 images show stronger noise, which subsequently reduces fine detail further and softens things up a bit more. At prints sizes up to 13 x 19 inches, quality is very good; there's still a lot of detail at this size, and noise remains limited to the shadows and has a rather fine-grained appearance. However, we'd be okay with a 16 x 20 inch print for less critical applications at this sensitivity.

ISO 1600 prints top-out at a respectable 11 x 14 inches. Noise is quite visible now at higher print sizes and is also taking its toll on low-contrast detail -- detail the red-leaf fabric of our test target images has become pretty soft and mushy. At 11 x 14, however, noise appears under control and not overly problematic from a quality standpoint.

ISO 3200 images really start to show the impact of the rising ISO sensitivity. There's an overall softness to lots of detail (and our red-leaf fabric swatch is nearly devoid of any detail whatsoever), but, by keeping sizes at 8 x 10 inches or below, you can still make some excellent prints with good detail and great colors.

ISO 6400 prints should be kept at 5 x 7 inches at maximum. Noise is quite apparent and really hurts fine detail at larger sizes.

ISO 12,800 images, unfortunately, are too soft and lacking in detail for us to comfortably consider usable for a print. However, for less critical applications, we'd be okay with a 4 x 6 inch print.

While the Canon G7X Mark II uses the same or very similar 20-megapixel 1-inch-type sensor as well as the same lens as the original Mark I model, it brings an all-new DIGIC 7 image processor to the table. Overall, it does a great job in the print quality department, offering about a print size larger than the G7X at the lower ISOs. At base ISO or ISO 200, the Canon G7X II is capable of crisp, colorful prints up to an impressive 24 x 36 inches. Even at ISO 800, the G7X II matches its predecessor with a very nice 13 x 19 inch print, and even a solid 8 x 10 all the way until ISO 3200. Despite its pocketable size, the G7X Mark II can still make nice, usable 5 x 7 inch prints up to ISO 6400. But at ISO 12,800, the Canon G7X II, like the original, captures images that are simply too noisy and lacking in detail to make acceptable prints.

 

The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Canon PowerShot G7 X Mark II Photo Gallery .

Not sure which camera to buy? Let your eyes be the ultimate judge! Visit our Comparometer(tm) to compare images from the Canon PowerShot G7 X Mark II with those from other cameras you may be considering. The proof is in the pictures, so let your own eyes decide which you like best!



Editor's Picks