Canon T6i Exposure

Saturation & Hue Accuracy
Realistic saturation levels with excellent hue accuracy.

Saturation. The Canon T6i produces images with saturation levels that are slightly less pumped than most cameras at default settings. Dark reds are boosted the most, with orange, dark greens and dark blues pushed a little, while cyans and light green are slightly muted. The mean saturation of 107.3% (7.3% oversaturated) at base ISO is slightly lower than average, and it's fairly stable across the ISO ranges, varying from a maximum of 109.5% at ISO 3200 to a minimum of 106.7% at ISO 12,800. 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. The Canon T6i produces pleasing, natural-looking Caucasian skin tones in our tests when using manual white balance. Darker skin tones show a small nudge toward orange, but lighter tones are more pinkish. Very good results overall. 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. As we've come to expect from Canon, the T6i's hue accuracy is excellent when manual white balance is used (as it always is for these results), and is much better than average. There are the usual shifts in cyan toward blue (though actually quite small), red toward orange, orange toward yellow, but all are fairly minor and there's virtually no shift in yellow (which is often shifted towards green). Average "delta-C" color error at base ISO is only 3.37 which is first-rate, one of the better scores we've recorded to date. Delta-C color error increases with ISO, but remains better than average even at the highest ISOs. Hue is "what color" the color is.

Exposure and White Balance

Indoors, incandescent lighting
Auto and Incandescent settings both struggled with household incandescent lighting, though Manual white balance worked well. Slightly higher than average exposure compensation required.

Indoors, under incandescent lighting, the Canon T6i's Auto and Incandescent white balance settings struggled, producing very warm reddish or orange/yellow color casts. Unfortunately, this is not uncommon among cameras we've tested, but disappointing nonetheless. The Manual setting produced the most accurate results, though just slightly cool with a small nudge towards green. The Canon T6i required +0.7 EV exposure compensation for this shot, which is slightly higher than the +0.3 EV average among the cameras we've tested. (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
Very good color, though a tendency towards slightly cool color balance with somewhat high contrast under harsh lighting. Average exposure accuracy.

Outdoors, the Canon T6i tended toward a slightly cool color balance with auto WB, so we preferred the manual white balance setting for our "Sunlit" portrait shot above left for its warmer skin tones, though overall color is generally very good. The Canon T6i required +0.7 EV exposure compensation to keep the mannequin's face bright, about average for this shot. The Canon T6i's default contrast is a little high, producing some washed-out highlights and dark shadows under the deliberately harsh lighting of the shot above left, though the camera's contrast, Auto Lighting Optimizer and Highlight Tone Priority settings help with high contrast scenes like these. See below for examples of this. The Far-field shot (above right) is also a bit cool with auto white balance, but exposure is pretty good, perhaps just slight dim. But the camera avoided blowing almost all highlights, though there are some deep shadows which contain moderate amounts of noise.

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

Resolution
~2,700 lines of strong detail from JPEGs, about 2,800 from RAW.

Our laboratory resolution chart showed the Canon T6i's images with sharp, distinct line patterns down to just over 2,700 lines per picture height horizontally and to about 2,700 lines vertically. Some may argue for higher numbers, but lines begin to merge at this resolution, and some aliasing artifacts in the form of moiré patterns can be seen as low as 2,300 lines. Extinction of the pattern occurred between 3,400 and 3,600 lines. An Adobe Camera Raw converted .CR2 file shows slightly higher resolution than the in-camera JPEG, perhaps another 100 lines, though complete extinction of the pattern was extended to between 3,600 and 4,000 lines, close to the limit of our chart. While ACR was able to extract more detail, it also produced more moiré and false colors. 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
Slightly soft images at default sharpening, but with noticeable sharpening artifacts. Minor to moderate detail loss due to noise reduction processing even at low ISOs.

Sharpness. The Canon T6i's 24-megapixel sensor captures very good image detail when coupled with a good lens, though JPEG images are a bit soft. (Keep in mind Canon has decided to keep an optical low-pass filter in the T6i to reduce aliasing artifacts at the cost of slightly reduced sharpness, unlike some competing models which have gone the other way. However the T6i's OLPF appears to be fairly weak.) Yet the T6i's default sharpening setting generates visible edge-enhancement artifacts in the form of obvious sharpening halos around high-contrast edges, as shown in the crop above left. 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 detail loss due to noise suppression in darker areas and in areas with low contrast, perhaps just a little more than we're accustomed to seeing from a digital SLR at base ISO. Still, a good performance for a 24-megapixel APS-C model. 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 T6i produces JPEG images with very good detail, but that are somewhat soft with visible sharpening halos. With a good RAW converter, additional detail can often be extracted with fewer sharpening artifacts. See below:

In the table above, we compare a best quality 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 (300%, radius of 0.3 pixels, and a threshold of 0).

Looking closely at the images, we can see ACR extracts additional detail that isn't present in the JPEG from the camera, particularly in the red-leaf and pink swatches where the fine 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, the conversion isn't as clean and smooth looking, with more noise that can be seen in the flatter areas of 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. And, as expected, sharpening halos aren't nearly as strong as the default camera output. Still, not bad in-camera default JPEG processing, but as usual you can do noticeably better by shooting in RAW mode and using a good RAW converter.

ISO & Noise Performance
Pretty good high ISO performance for a high-res APS-C sensor.

Images are quite clean at ISOs 100 and 200, with just a tiny amount of luminance noise seen in the darker areas, and very little chroma noise. Some blurring of fine low-contrast detail is already visible at base ISO, though, as mentioned previously. Noise "grain" is slightly more evident at ISO 400, but detail remains very strong despite some minor blurring due to noise reduction. ISO 800 is of course a little noisier, but fine detail is still very good with a noise grain that's quite fine and chroma noise well under control. At ISO 1600 blurring becomes noticeably stronger resulting in a more evident drop in image quality, though a fair amount of fine detail is still left. ISO 3200 is quite a bit grainier with minor chroma noise, but there is still some fine detail left. ISO 6400 is quite grainy, but the grain is still fairly tight and not too obtrusive. Noise and the effects of noise reduction working hard to keep it under control really become apparent at ISOs 12,800 and 25,600 with heavier luminance noise, stronger blurring and more obvious chroma blotching.

All-in-all, pretty good high ISO performance for its class, though not quite as good as some rivals.

As always, see the Print Quality section below for maximum recommended print sizes at each ISO, as printed results often don't correlate well to images viewed on a monitor at 100%.

A note about focus for this shot: We used to shoot this image at f/4, however depth of field became so shallow with larger, high-resolution sensors that it was difficult to keep important areas of this shot in focus, so we have since started shooting at f/8, the best compromise between depth of field and sharpness.

Extremes: Sunlit, dynamic range and low light tests
Very high resolution with strong overall detail, but somewhat high default contrast and unremarkable dynamic range. HTP and ALO options do a great job of dealing with tough lighting. Very good low-light performance.

The Canon T6i produces images with moderately high contrast with some washed-out highlights and deep shadows under the deliberately harsh lighting of the test above. The mannequin's face was too dim at the default and +0.3 EV settings and too many highlights were blown with +1.0 EV, so we preferred the image with +0.7 EV exposure compensation. This resulted in some clipped highlights in the shirt and flowers, a bit more than we're used to seeing from an APS-C sensor lately, indicating mediocre use of available dynamic range compared to the best of recent competitors. Shadow detail was however pretty good, though very deep shadows are a bit noisy and posterized. Bottom line: while dynamic range isn't bad, the Canon T6i didn't do as well with this difficult shot compared to some recent state-of-the-art peers.

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. In actual shooting conditions, be sure to use fill flash in situations like the one shown here; it's better to shoot in open shade whenever possible.)

Face Detection
Just like most point & shoot cameras these days, the Canon T6i has the ability to detect faces in Live View mode, and adjust exposure and focus accordingly.

As you can see from the examples above, it works well, as the center image with face detection enabled is better exposed for the face than the left image where face detection was not employed. Full Auto mode (right) was also an improvement over Aperture Priority without face detection, selecting a larger aperture than we normally use for this shot (f/3.5 vs f/8). Good results here.

Highlight Tone Priority
The Canon T6i's Highlight Tone Priority (HTP) option did an excellent job of preserving highlight detail, though shadows were also affected, as shown below. (Mouse over the Off and On links to load the corresponding thumbnail, histogram and crops.)

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 ISO to 200; part of how HTP works. The result is evident in the histograms and thumbnails above, clearly showing the superior highlight preservation when HTP is enabled, though shadow brightness is also affected somewhat. 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 from 100 to 200.

Automatic Lighting Optimization
Like previous Canon EOS models, the T6i offers three selectable levels of Automatic Lighting Optimization (ALO), plus Off. In fully automatic (Scene Intelligent Auto) ALO is automatically enabled and it's available in P, Tv and Av exposure modes. Mouse over the links below to load the associated thumbnail and histogram, and click on the links to load full resolution images.

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.

HDR Backlight Control
Like its predecessor, the T5i, the Canon T6i has an HDR Backlight Control scene mode, which takes three continuous shots at different exposures and merges them together to create an image with wider tonal range than would be possible with a single exposure. We did not however test this scene mode in the lab.

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 T6i's (750D) dynamic range to its predecessor, the T5i (700D), and also to Nikon's D5500. You can always compare other models on DxOMark.com.

As you can see from the above graph (click for a larger version), the Canon T6i's dynamic range is improved over the T5i's across the board, with a peak of about 12.0 versus 11.2 EV at base ISO, and a minimum of about 6.6 vs 5.7 EV at the ISO 25,600 setting.

The Nikon D5500 does significantly better at low to moderate ISOs, though, with a peak of about 14.0 EV at base ISO which is a whopping 2 EV advantage. But as ISO rises, the gap shrinks and the two cameras perform very similarly at ISO 1600 and above. Click here to visit the DxOMark page for the Canon T6i for more of their test results and additional comparisons.

Low Light. The Canon T6i performed well in our low-light tests, 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 luminance noise remains fairly low and fine-grained at ISO 3200. Some chroma noise in the form of subtle color blotching in the shadows and dark areas is visible at lower light levels, though it's effectively suppressed by default noise reduction. As you'd expect, noise is quite high at the maximum ISO of 25,600, particularly when noise reduction is minimized (extreme right column in the table above).

We noticed a few hot pixels here and there, but nothing out of the ordinary. We didn't see any signs of heat blooming and banding (fixed pattern noise) appears to be very low, though random noise in very deep shadows is a bit high.

Color balance was fairly neutral with Canon T6i's Auto white balance setting, just a touch cool at higher light levels, but warming up at lower.

When using the optical viewfinder and dedicated phase-detect AF, the Canon T6i's autofocus system was able to focus on the subject down to just above the 1/16 foot-candle light level unassisted with an f/2.8 lens. That's good for a consumer DSLR, and the camera was able to focus in complete darkness with AF assist enabled. In Live View mode with Hybrid AF, the Canon T6i was almost able to focus down to the same light level as with the optical viewfinder, which is also very good for a consumer DSLR in Live View mode with an f/2.8 lens.

As always, keep in mind that the longer shutter speeds here demand the use of a tripod to prevent any blurring from camera movement. (A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

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.) Digital SLRs like the Canon T6i do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.

Print Quality
High-quality prints up to 30 x 40 inches at ISO 100-400; Nice 13 x 19 inch prints at ISO 3200; and 4 x 6 inch prints just pass muster at ISO 25,600.

ISO 100/200/400 images looks impressive up to a whopping 30 x 40 inches. At all three sensitivities, prints of our Still Life test images look very good with lots of fine detail and pleasing colors. 30 x 40 prints are quite large, and the largest we test-print now at IR. You're really only limited by how much you want to push the 24-megapixel sensor's resolution should you wish to print larger sizes.

ISO 800 prints still look very, very good, and in fact, quite close to the previous three ISOs at 24 x 36 inches. However, we can see that subtle shadow noise has become more apparent at this sensitivity, making a 20 x 30 inch print the largest size with our stamp of approval. That said, colors and detail are still very good, so a 24 x 36 print could do well for less critical applications.

ISO 1600 images look great up to 16 x 20 inches. Noise in the shadows is more visible now, though finely grained, but overall, prints at this size show a lot of detail and pleasing colors.

ISO 3200 prints do nicely up until 13 x 19 inches. At this point, noise is heavier, though it still has a fine-grained quality to it, but nevertheless it prevents us from calling larger print sizes acceptable. Fine detail and colors are still quite good at this print size, though.

ISO 6400 images look great up to 8 x 10 inches. Naturally, noise is stronger and more apparent at this ISO now, but there's still a good amount of detail, and colors are pleasing.

ISO 12,800 prints max-out at 5 x 7 inches. Detail becomes too soft due to noise to really consider any larger print sizes acceptable.

ISO 25,600 images manage to squeak out a rather pleasant 4 x 6 inch print. Colors still look surprisingly good, and there's just enough detail to make a decent print at this size.

Sporting the highest-resolution APS-C sensor ever packed into a Rebel-series camera, the 24-megapixel Canon T6i has an impressive showing in the print department. Surprisingly, prints from ISO 100 up to 400 look practically identical with tons of detail and great colors allowing for very large prints up to 30 x 40 inches. Hitting the middle ISO ranges, the T6i does very well to control noise and balance NR processing with a good amount of fine detail. At ISO 3200, the T6i manages a nice 13 x 19 inch print. And even at the tip-top of the ISO scale, this new Canon Rebel achieves a good 5 x 7 at ISO 12,800 and a 4 x 6 at 25,600.