Canon PowerShot G1 X Image Quality
Saturation & Hue Accuracy
Fairly accurate saturation levels with about average hue accuracy, though yellows were a little problematic.
Saturation. The Canon G1 X produced fairly accurate saturation levels overall, with only minor oversaturation in reds, greens, browns, and purples, and moderate overstaturation in blues. Bright yellow, aqua, and cyan were undersaturated by a small to moderate amount. Average saturation is 107.4%, or 7.4% oversaturated, which is more true to life than most cameras these days. Overall, the Canon G1 X's images appeared to have natural looking color that was a touch muted compared to other cameras, though you can always adjust saturation to your liking. 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. Here, with Auto white balance in simulated daylight, the Canon G1 X rendered lighter Caucasian skin tones a little yellow and flat, while darker ones were more pinkish. 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 G1 X 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 was 5.32; about average compared to most cameras, though the shift and reduced saturation in yellows was noticeable in some of our shots. Hue is "what color" the
| See full set of test images
See thumbnails of all test and gallery images
Exposure and White Balance
Indoors, incandescent lighting
Very good color balance with Auto and Manual white balance settings. Average exposure accuracy.
|Auto White Balance
|Incandescent White Balance
|Manual White Balance
Color balance indoors under incandescent lighting was very good with the Auto white balance setting, with just a hint of a magenta tint. The Canon G1 X did much better here than the majority of digital cameras we've tested. The Incandescent white balance option resulted in a pinkish cast, while the Manual white balance setting was pretty accurate if a touch cool, with just a slight blue/green bias. The PowerShot G1 X's exposure system handled this lighting well, requiring an average amount of exposure compensation of + 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.
Slightly cool colors, with high default contrast.
|Auto White Balance,
|Auto White Balance,
The Canon PowerShot G1 X struggled a bit under harsh outdoor lighting of our "Sunlit" Portrait shot, as default contrast was quite high. Slightly above average exposure compensation of +1.0 EV was needed to keep the model's facial skin tones bright, resulting in a lot of blown highlights in her shirt and flowers. Most cameras require about +0.7 EV. On the other hand, overall exposure was very good in the outdoor far-field shot at the default exposure, with surprisingly few clipped highlights and few lost shadows. Color outdoors was good with the Auto white balance setting, just a touch cool and muted, though the camera rendered some skin tones a little too flat and yellow.
Very high resolution, ~1,800 lines of strong detail from in-camera JPEGs, 1,800 to 1,900 lines from converted RAW files.
Strong detail to
1,800 lines horizontal
Strong detail to
1,800 lines vertical
|DPP converted RAW:
Strong detail to
1,900 lines horizontal
|DPP converted RAW:
Strong detail to
1,800 lines vertical
Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,800 lines per picture height in both the horizontal and vertical directions in JPEGs straight out of the camera. (Some might argue for over 1,800 lines, but aliasing artifacts such as moiré patterns begin to appear at lower resolutions.) Extinction of the pattern occurred between 2,600 and 2,800 lines in the horizontal direction, and between 2,800 to 3,000 lines in the vertical direction. Canon's Digital Photo Professional wasn't able to extract significantly more resolution, perhaps another 100 lines in the horizontal direction, but applying less sharpening than the camera avoided some of the aliasing artifacts seen near the limits of resolution. 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.
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, though much better than average results here.
|Very good definition of high-contrast
elements, with some visible
|Subtle detail: Hair
Noise suppression blurs
detail in areas of subtle contrast,
as in the darker parts of hair here.
Sharpness. The Canon PowerShot G1 X captures fairly sharp JPEG images at default settings, though some edge enhancement artifacts are visible on high-contrast subjects such as the halos around the pine cones and branches in the crop above left. Still, pretty good results here. 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 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 much better than average for a compact digicam and compares well to some DSLRs. 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 G1 X produces fairly sharp, detailed in-camera JPEGs. With a good RAW converter, more detail can often be extracted, though. See below:
In the table above, mousing over a link at the bottom will load the corresponding crop in the area above, and clicking twice will open the full resolution image.
The image loaded by the left-most link is a crop from an in-camera Fine JPEG taken with default settings. The next image is a RAW file processed using Canon's included Digital Photo Professional software, using default settings. The third image was converted with DxO Optic Pro 7, using default settings. The right-most image was converted with Adobe Camera Raw 6.7, then sharpened in Photoshop using Unsharp Mask of 300%, radius 0.3. As you can see, Canon's Digital Photo Professional software wasn't really able to extract more detail than the in-camera JPEG, and it applies significantly more sharpening than the camera default leaving more noticeable sharpening halos. DxO Optics Pro 7 did a better job at retaining fine detail than DPP with far fewer sharpening artifacts, though it tended to introduce a few more demosaicing errors. We preferred the Adobe Camera Raw conversion for its more natural looking rendering of fine detail, though it does show more noise than the others (you can always adjust noise reduction to your taste, though). The ACR conversion also shows more chromatic aberrations, however we did not attempt to reduce it during conversion.
ISO & Noise Performance
Very good high ISO performance up to ISO 800, and even ISO 1,600 is quite good.
|Default Noise Reduction|
|ISO 100||ISO 200||ISO 400|
|ISO 6,400||ISO 12,800|
The PowerShot G1 X performed well here, with very good noise performance up to ISO 800. There's a bit of softening in the hair at ISO 800, as well as some fine-grained luminance noise and some chroma noise in the shadows, but fine detail is really quite good. ISO 1,600 is a little softer from more aggressive noise reduction, but detail is still pretty good. ISO 3,200 is noticeably softer, though, with chroma noise becoming quite evident in darker areas, though much of the luminance noise is smoothed away. Luminance noise is much stronger at ISO 6,400, making the image look less processed than ISO 3,200. ISO 12,800 is pretty noisy as you'd expect, with little fine detail and noticeable chroma noise in the form of green and purple blotches. Still, high ISO performance is much better than compact cameras, though not as good as the best APS-C DSLRs. Note that the G1 X offers three levels of noise reduction (Low, Standard and High). These shots were taken using the default Standard setting.
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
High resolution with strong detail, though limited dynamic range. Excellent 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 G1 X struggled a bit under the deliberately harsh lighting in the test above. To keep facial tones bright, +1.0 EV compensation was require, but that led to a lot of washed-out highlights, more than we're used to seeing. Detail was pretty good in the shadows, though. Some may prefer the +0.7 EV setting for its reduced highlight clipping, but we found the face a bit too dim. 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.)
Dynamic Range Analysis
A key parameter in a digital camera is its Dynamic Range, the range of brightness that can be faithfully recorded. At the upper end of the tonal scale, dynamic range is dictated by the point at which the RGB data "saturates" at values of 255, 255, 255. At the lower end of the tonal scale, dynamic range is determined by the point at which there ceases to be any useful difference between adjacent tonal steps. Note the use of the qualifier "useful" in there: While it's tempting to evaluate dynamic range as the maximum number of tonal steps that can be discerned at all, that measure of dynamic range has very little relevance to real-world photography. What we care about as photographers is how much detail we can pull out of the shadows before image noise becomes too objectionable. This, of course, is a very subjective matter, and will vary with the application and even the subject matter in question. (Noise will be much more visible in subjects with large areas of flat tints and subtle shading than it would in subjects with strong, highly contrasting surface texture.)
What makes most sense then, is to specify useful dynamic range in terms of the point at which image noise reaches some agreed-upon threshold. To this end, Imatest computes a number of different dynamic range measurements, based on a variety of image noise thresholds. The noise thresholds are specified in terms of f-stops of equivalent luminance variation in the final image file, and dynamic range is computed for noise thresholds of 1.0 (low image quality), 0.5 (medium image quality), 0.25 (medium-high image quality) and 0.1 (high image quality). For most photographers and most applications, the noise thresholds of 0.5 and 0.25 f-stops are probably the most relevant to the production of acceptable-quality finished images, but many noise-sensitive shooters will insist on the 0.1 f-stop limit for their most critical work.
JPEG. The graph at right (click for a larger version) was generated using Imatest's dynamic range analysis for an in-camera Canon G1 X JPEG file with a nominally-exposed density step target (Stouffer 4110). At the base ISO of 100 (the optimal ISO) and with default settings, the graph shows 9.96 f-stops of total dynamic range, with 7.25 f-stops at the "High" Quality level. Roll-off at the highlight end of the curve was fairly gradual, but for shadows it wasn't as gradual.
We don't normally use Imatest to measure dynamic range for compact cameras, but these results compare well to most Micro Four Thirds cameras, however they're not as good as most APS-C models. Compared to the Canon 60D (which lags behind most SLRs and CSCs based on Sony's latest APS-C sensors in terms of dynamic range), the G1X scored similarly at the High Quality level (7.25 vs 7.46 f-stops) when you take margin of error into account (about 1/3 f-stop for this test), but lower in total dynamic range (9.96 f-stops vs 10.5).
RAW. The graph at right is from the same Stouffer 4110 stepchart image captured as a RAW (.CR2) file, processed with Adobe Camera Raw using the Auto setting. (Slightly better results are likely possible with manually tweaking, but we weren't able to do much better.) As can be seen, the score at the highest quality level was only slightly better than the in-camera JPEG, at 7.56 vs 7.25 f-stops, though total dynamic range increased about 1.3 f-stop, to 11.3 versus 9.96 f-stops; usable dynamic range will be somewhere in between. Again, these results aren't bad compared to a Micro Four Thirds sensor, but they lag current APS-C sensors, especially at the High Quality threshold. The Canon 60D managed a score of 7.75 f-stops at the High Quality level while total dynamic range was 11.9 f-stops, and Sony-based APS-C sensors do much better. It's worth noting here is that ACR's default noise reduction settings reduced overall noise somewhat (see the plot in the lower left-hand corner) relative to the levels in the in-camera JPEG, which would tend to boost the dynamic range numbers for the higher quality thresholds.
As part of the G1 X'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 G1 X's three available Dynamic Range Correction settings. Mouse over the links about right to compare, and click on the links to get to the full-resolution images. The resulting images are a little dim at default exposure (in hindsight, it would have been better to shoot these at +0.7 or +1.0 EV compensation), but you can see that highlights were toned-down progressively with the DR 200% and DR 400% settings. The results with DR Auto were practically identical to being set to Off, since few highlights were blown to begin with. We didn't test the G1 X's Shadow Correction, but in prior Canon models it boosted shadows without impacting highlights, leading to the best overall exposure for this shot.
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 200 and DR 400% used ISO 400, while DR Auto left ISO at 100.)
|Face Detection Examples|
The table above shows results with the default exposure using Aperture Priority AE, as well as Face Detection enabled and Smart Auto. As you can see, the G1 X's face detection and Smart Auto mode both improved exposure automatically compared to the default exposure in Aperture Priority mode, going from very underexposed to usable images. Face detection dropped the shutter speed from 1/50s to 1/25s to improve the exposure for the face, while keeping ISO (100) and aperture (f/8.0) the same as before. Smart Auto also detected the face, but boosted ISO to 400, used a larger aperture (f/5.6) and a faster shutter speed (1/60s). Overall, we preferred the Smart Auto image as the camera also seemed to apply Intelligent Contrast resulting in far fewer blown highlights as well as more open shadows.
Low Light. The Canon PowerShot G1 X performed well on the low-light test, capturing bright images at the lowest light level (1/16 foot-candle), even with the lowest sensitivity setting (ISO 100). As expected, noise increases as ISO goes up and light levels go down, but noise remains remarkably low up to ISO 1,600, and even ISO 3,200 looks pretty good. Noise is a little high at ISOs 6,400 and 12,800, but that's to be expected and much better than most compact cameras. Color balance was pretty good with Canon G1 X's Auto white balance setting, just a touch cool, even at high ISOs and low light levels. There are a few bright pixels visible at all ISOs, but nothing to be concerned about. We did notice some faint horizontal chroma banding at lower light levels and very high ISOs, but that's not unusual.
The camera's AF system was able to focus unassisted to below the 1/16 foot-candle light level in our tests, which is very good, and the G1 X 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.
Coverage and Range
A fairly powerful flash for its size, with uneven coverage at wide-angle. Good exposures in our indoor portrait test shots, but watch out for slow shutter speeds.
|28mm eq., f/2.8, ISO 320||112mm eq., f/5.8, ISO 400|
|Normal Flash, ISO 200 (+0.7 EV)||Slow-sync Flash, ISO 200 (+1.0 EV)|
|Auto Flash, ISO 400|
Coverage. Flash coverage was quite uneven at wide-angle (not unusual), with much more uniform results at full telephoto.
Exposure. Given that a lot of small cameras have difficulty with our Indoor Portrait flash shots at ISO 100, we've switched to shooting them at ISO 200. Here, the G1 X's flash performed well, requiring +0.7 EV of exposure compensation which is about average for this scene. The camera selected 1/60 second shutter speed, which is good. Slow-sync flash mode produced a more evenly lit image, but needed a bit more exposure compensation at 1.0 EV, even though it used a slow shutter speed of 1/8 second which requires the use of a tripod and a very still subject. The white balance here is actually pretty good, as slow-sync mode normally produces quite an orange cast from the ambient lighting. We can attribute the improved flash white balance to the new DIGIC 5 processor. Auto mode produced a bright image at ISO 400 (automatically selected), but it used a fairly slow shutter speed of 1/20 second, which could lead to some issues with subject motion blur.
ISO 200 Range. At wide-angle and ISO 200, flash shots were bright to about 14 feet, though images at 15 and 16 feet were still usable. At full telephoto, flash shots were bright to 8 feet, and got darker from there.
|Manufacturer-Specified Flash Range|
Auto ISO 400
Auto ISO 400
Manufacturer Specified Flash Test. Canon rates the PowerShot G1 X's flash range at 7 meters / 23 feet at wide-angle and 3.1 meters / 10.2 feet at telephoto, when using Auto ISO. In the shots above, the PowerShot G1 X's flash performed to Canon's specifications, producing bright images at wide-angle and full telephoto, though the camera boosted ISO to 400 in both cases.
Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. We now also shoot two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the specific claims.
Great 24x36-inch prints at ISO 100; ISO 800 shots make good 16x20-inch prints; even 12,800 make usable 5x7s!
ISO 100 images are usable at 24x36 inches, but perhaps a little too "loose." They tighten up at 20x30, looking quite good with sharp detail and good color. We need to qualify that, though, because the yellows are uncharacteristically subdued for a Canon camera, something we saw in the crops as well.
ISO 200 shots also look great printed at 20x30.
ISO 400 shots look great at 20x30, with the slightest hint of softening in some textures, but it's only noticeable on close inspection.
ISO 800 images look better at 16x20 inches, with excellent detail and good color. Our red leaf swatch still looks quite good at ISO 800, a nice surprise.
ISO 1,600 images have a more processed look at 16x20, but very little actual chroma or luminance noise is left behind. There's no good reason for a size reduction, though, as the images look quite good.
ISO 3,200 shots are usable at 13x19, but that processed look has become more pronounced, so I prefer the 11x14-inch prints.
ISO 6,400 images seem a little too loose at 11x14, and the red leaf swatch has sporadic detail, the first time we've seen something other than total blur from a Canon camera. I'd call them usable at 11x14, but they're much better printed at 8x10.
ISO 12,800 shots are a bit too smudgy and dark for printing at 8x10, but detail looks better at 5x7. I think you'd want to brighten the images a bit, as the darks are really dark at this point.
Overall, the Canon G1 X does well, though not quite as well as SLRs as the ISO rises. An impressive performance nonetheless.
Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon Pro9000 Mark II studio printer, and on the Canon Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)