Canon 50D Image Quality
Canon EOS 50D Image Quality
Saturation & Hue Accuracy
Vibrant color with minor oversaturation of strong reds, blues and oranges.
Saturation. The Canon EOS 50D pushes reds, blues and oranges, while undersaturating some cyans and purples, but the generally slightly bright color will most likely be very appealing to many users. 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, the Canon 50D also did quite well, producing natural-looking 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 EOS 50D showed a few small color shifts relative to the correct mathematical translation of colors in its subjects, but had really excellent accuracy overall. Most noticeable was a slight shift in reds toward orange, and slightly larger one in orange toward yellow, with some very minor shifts in greens and cyans as well. Hue is "what color" the color is.
The Canon EOS 50D has a total of nine saturation settings available, four above and two below the default saturation. This covers a very wide range of saturation levels, about as wide a range as you're likely to find photographically relevant, apart from special effects that are arguably better achieved in software. The fine steps between settings mean you can program the camera to just the level of saturation you prefer. Nice. (It's also nice that color saturation has little effect on greyscale contrast, something that's not always the case.)
|Saturation Adjustment Examples|
The table above shows results with the default as well as the two extreme saturation settings. Click on any thumbnail above, then click again to see the full-sized image.
|See full set of test images with explanations
See thumbnails of all test and gallery images
Exposure and White Balance
Indoors, incandescent lighting
Very warm results with Auto and Incandescent white balance settings, though good color with the 2,600 Kelvin and Manual. Average positive exposure compensation required.
|Auto White Balance
|Incandescent White Balance
|Manual White Balance
Indoors, under normal incandescent lighting, color balance was very warm with the Auto white balance setting; we'd really expect better from an SLR selling at this price point. The Incandescent setting was better, but still on the warm side. (The EOS 50D's Incandescent setting appears to be color-balanced for professional studio lighting, rather than the warmer household incandescent lights most US consumers have in their homes. This would be normal for a professional SLR, but a bit of a pain for consumers. Still, you can use the 50D's excellent manual adjustment capabilities to tweak the incandescent setting to better match whatever lighting you're faced with personally.) The Manual setting produced the most accurate results, though the 2,600 Kelvin setting wasn't far off the mark either. The Canon EOS 50D required an average amount of positive exposure compensation here, at +0.3 EV. (Many digital cameras reproduce the blue flowers here with a purplish tint, so the Canon EOS 50D actually performs a little better than average here.) 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.
Bright colors overall, though a tendency toward a warm cast and slightly high contrast under harsh lighting. About average exposure accuracy.
|Auto White Balance,
|Auto White Balance,
Outdoors, the Canon EOS 50D tended toward a warmer color balance, though overall color was generally quite good. The EOS 50D performed about average in terms of exposure, requiring the typical amount of positive compensation we're accustomed to seeing among digital cameras. The far-field shot of the house came out just a bit hot at the EOS 50D's default exposure setting. The EOS 50D's default contrast is a little high, producing some washed-out highlights and dark shadows under the deliberately harsh lighting of our "Sunlit" portrait test shown above left, but the 50D does better than most in this regard. The camera's contrast and highlight tone priority settings do help tame the highlights quite a bit, see below for examples of this.
Very high resolution, 1,700 ~ 1,800 lines of strong detail from in-camera JPEG, about the same from RAW file processed through Adobe Camera Raw.
Our laboratory resolution chart revealed sharp, distinct line patterns down to about 1,800 lines per picture height horizontally, and about 1,700 lines in the vertical direction. Extinction didn't occur until about 2,600 lines horizontally and vertically (results from 2X target are multiplied by 2). We weren't able to extract much more resolution by processing the EOS 50D's CR2 files using Adobe Camera Raw, although the vertical resolution (horizontally-oriented target lines) improved slightly. 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
Soft images overall, though almost no edge-enhancement artifacts on high-contrast subjects. Some minor noise suppression visible in the shadows.
Sharpness. The Canon EOS 50D captures slightly soft images overall (made worse by the soft kit lens used for the far field house shot), though very few edge enhancement artifacts are visible on high-contrast subjects such as the crop above left. This indicates default sharpening is somewhat conservative. 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 minor noise suppression artifacts in the darkest areas of the model's hair, though quite a few individual strands are visible in the lighter shadows. The camera's overall response here is better than average. 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 EOS 50D produces rather soft in-camera JPEGs using the kit lens. To show more what the camera's capable of, all of our FAR shots except the Tele/Wide coverage examples were shot with a Canon 35mm f/2.8 prime (non-zoom) lens, stopped down to f/8 for best sharpness (as determined by our tests of that lens on SLRgear.com). As is almost always the case, more detail can be obtained from carefully processing RAW files than can be seen in the in-camera JPEGs, but the Canon 50D's JPEGs aren't bad. Take a look below, to see what we mean:
In the table above, mousing over a link at the bottom will load the corresponding crop in the area above. Examples include in-camera Fine JPEG, RAW file processed through Canon's Digital Photo Professional (DPP) software, and RAW file processed through Adobe Camera Raw (ACR) version 4.6, then sharpened in Photoshop. (For the Canon EOS 50D's images, I found best results with 320% unsharp masking with an 0.3 pixel radius.) Manufacturer software often doesn't find as much detail as does Adobe Camera RAW, but Canon's DPP does better than most - The image processed through ACR show a little more detail, but it looks to our eyes more as though it's the result of tone curve differences than fundamental differences in the amount of information extracted. Regardless, the Canon 50D is clearly a camera that carries a lot of data in its RAW files.
ISO & Noise Performance
Pretty low noise except at the highest sensitivity settings, good preservation of subtle detail relative to ISO level.
Default High ISO Noise Reduction
|ISO 100||ISO 200||ISO 400|
|ISO 800||ISO 1600||ISO 3200|
|ISO 6400||ISO 12800|
The Canon EOS 50D produced pretty low image noise overall. Images are quite clean at ISOs 100 and 200. We start to see a very fine, tight "grain" pattern at ISO 400, but detail is still excellent, with no signs of chroma noise. The grain is slightly more evident at ISO 800, but detail continues to remain strong. At ISO 1,600, we begin to see some minor detail loss as noise reduction blurs subtly contrasting detail, however results are still quite good. At ISO 3,200, noise grain is courser and blurring stronger, resulting in a noticeable drop in detail. We also start to see some chroma noise, a few bright pixels as well as some minor horizontal banding in shadow areas. Noise and the effects of noise reduction really become a problem at ISO 6,400 and especially at ISO 12,800, with brighter noise pixels, increased chroma noise, heavier banding and a shift in overall color balance. Still, an excellent performance, especially for a camera with a 15-megapixel APS-C size sensor. As always, see the Print Quality section below, to find out what we recommend for maximum print sizes at each ISO setting.
Extremes: Sunlit and low light tests
Very high resolution with strong overall detail, but slightly high default contrast. Excellent low-light performance, great exposure to the lowest limits of our test, and the autofocus worked that low, even without the AF-assist light.
|+0.3 EV||+0.7 EV||+1.0 EV|
Sunlight. The Canon EOS 50D produced slightly high contrast with some washed-out highlights and deep shadows under the harsh lighting of the test above. However, highlight and shadow detail is actually pretty good. The model's face was a little dim at the +0.3 EV setting, so we preferred the image with +0.7 EV of exposure compensation, which actually resulted in good detail in her shirt as well: It looks blown out on-screen, but if you play with the image in Photoshop, you'll see that there's almost no clipping in the shirt; the blue channel just nudges 255 here and there. Compensation of +1.0 EV resulted in a too many clipped highlights for our tastes, though some shooters may prefer the brighter image for its better skin tones. (In real life, be sure to use fill flash in situations like the one shown above; 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.)
We really like it when a camera gives us the ability to adjust contrast and saturation to our liking. It's even better when those adjustments cover a useful range, in steps small enough to allow for precise tweaks. As was the case with its saturation adjustment, the Canon EOS 50D's contrast setting meets both challenges very well.
|Contrast set to lowest,
|Contrast set to lowest,
At its lowest contrast setting, the Canon EOS 50D did an excellent job of preserving highlight detail, maintaining fairly natural-looking skin tones, and holding nice detail in the shadows. The EOS 50D captures good color outdoors, though again, just slightly on the warm side. Overall, very good results here, especially when the contrast setting is tweaked.
|Contrast Adjustment Examples|
The table above shows results with the default as well as the two extreme contrast settings. While you can see the extremes, it's hard to really evaluate contrast on small thumbnails like these, click on any thumbnail to go to the full-size image. The Canon EOS 50D's contrast adjustment worked well, with little effect on color saturation. Contrast and saturation are actually fairly closely coupled adjustments, it's a good trick to be able to vary one with out the other changing as well. Canon did a good job here.
Highlight Tone Priority Examples
Shadow Detail, Brightened in Photoshop
(Levels control, highlight slider down to 75)
Canon's Highlight Tone Priority
The two shots above show the results with Highlight Tone Priority "Off "and "On". As you can see from the crops, fewer highlights in the model's white shirt are clipped, while shadow detail remains roughly the same when Highlight Tone Priority is enabled. Noise is a bit higher in the shadows, though, due to the increase in sensitivity to ISO 200 and the fact that the camera is using more of the available output tonal range in the highlights. (Note that these are really deep shadows that we're looking at above. Lighter shadows and quarter tones show very little noise increase.)
More Highlight Tone Priority Examples
The 50D's Highlight Tone Priority can however result in undesired results (even with firmware v1.0.2, which is supposed to address the HTP overexposure problem), as can be seen with the washed-out Still Life image above right. Canon was wise to keep the default "Off". (You need to make sure you have a significant area of strong highlights before enabling HTP.)
|Automatic Lighting Optimization Examples|
Automatic Lighting Optimization
The Canon 50D offers three levels of ALO, plus "Off" (the 40D didn't offer ALO and the Rebel XSi has only "On" or "Off"). All four shots above were taken with same exposure settings. With the Canon XSi, we found relatively little effect from Canon's Automatic Lighting Optimization feature on this shot, however the 50D's adjustable settings do make a noticeable difference. ALO has the effect of shifting shadows and mid-tones in the histograms to the right, lightening the overall image without clipping additional highlights.
Interestingly, scrutinizing the ALO Off and ALO High images above in Photoshop, when used the levels control to adjust two images to bring the shadows to the same brightness level, we were surprised to see that the image noise in the ALO Off image was more prominent than that in the ALO High version. This might be because the boosted shadows in the ALO High image had lower, more natural color saturation than those in the Off version. When we played with Photoshop's Shadow/Highlight controls, we found we could pretty well match what ALO High was doing by setting the amount of shadow fill to about 25 or so, while reducing the tonal width a little from its default of 50. This came close to what ALO was doing, but there was still a bit more noise in the shadows of the Photoshop-adjusted image. This is an example where automatic in-camera processing is doing a better job than unsophisticated use of even fairly advanced tools in an image editor. Pretty impressive.
Low light. The Canon EOS 50D performed quite well on the low-light test, capturing usable images at the lowest light level (1/16 foot-candle), even with the lowest sensitivity setting (ISO 100). Noise increases as ISO goes up and light levels go down, but remains very low up to ISO 800. At ISO 1,600, we start to see a few bright pixels, but noise is still fairly low. At ISO 3,200 and above, bright pixels appear more frequently, and horizontal banding increases, becoming quite evident at ISOs 6,400 and 12,800. Color balance looked a bit warm with the Auto white balance setting, resulting in a reddish cast at lower light levels.
Many readers will doubtless immediately compare the Canon 50D with the Nikon D90, as the two cameras were announced within a day of each other, and are somewhat competitive in the marketplace. The 50D has more pixels than the D90 and sells for a higher price, but the two are pretty comparable in many dimensions. Given Canon's long history of superb noise performance with their CMOS sensor technology, we were somewhat surprised to find that the D90 beat the 50D pretty handily in terms of noise at high ISOs and low light levels. The D90's images were softer, due in part to its lower resolution, but perhaps also to heavier noise suppression, but in terms of overall visceral impact, we much preferred the D90's noise characteristics to those of the 50D.
The camera's autofocus system was able to focus on the subject at less than the 1/16 foot-candle light level unassisted, and in complete darkness with the AF assist enabled. 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 EOS 50D do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects.
Great print quality, good color, sharp 13x19 inch prints from camera JPEGs, 16x20 inch ones from RAW files. (Even 20x30 prints from RAW are very usable for wall display.)
Working from RAW files, we thought that 20x30 inch prints would be very acceptable for viewing at any sort of normal distance: We could see softness in them when we looked close and squinted (well, maybe just looked close), but normal viewing distances of anything greater than a foot or so, they looked crisp and highly detailed. The in-camera JPEGs looked OK printed at 13x19, but were still a little soft there. Some fine/tight unsharp masking in Photoshop (0.3 pixel radius, perhaps 200-250% sharpening) helped the camera JPEGs somewhat, but the comparison with files processed from RAW was still pretty stark.
At higher ISOs, the 50D's images held together quite well. For 13x19 inch prints, ISO 1,600 was about the limit, as ISO 3,200 ones got soft and grainy at that size. Even viewed at a distance of a foot or more, the ISO 3,200 shots just showed too much fuzzy grain for our tastes at 13x19 inches, but the ISO 1,600 shots looked great.
Dropping to 11x14 inches, ISO 1,600 shots looked great, and ISO 3,200 looked good, although there was still a little chroma noise present. (Which went away in shots taken with high-ISO noise reduction set to its High setting.)
ISO 3,200 looked good at 8.5x11 and great at 5x7 inches. ISO 6,400 shots looked decent at 8x11, but how you feel about them will depend on how you feel about image noise vs detail.
With normal noise reduction, the prints from ISO 6,400 shots held good detail, but chroma noise was fairly visible in some of the darker fabric swatches on our Still Life target. Turning the noise reduction up to High eliminated most of the chroma noise but at the cost of some detail. At ISO 6,400, there was also some banding in the chroma noise in the shadows, that persisted even with High noise reduction, and that was visible even in somewhat smaller prints.
ISO 12,800 from camera JPEGs was pretty rough (lots of chroma noise with noticeable horizontal banding) no matter what size we printed at; plan on using it only as a last resort, or if you're using good third-party noise reduction software in your post-processing. (ISO 12,800 might also be usable for subjects with lots of texture, which would tend to mask the noise pattern.)
Detail throughout the ISO range stayed pretty strong. To their credit, Canon isn't turning the 50D's images into undifferentiated mush just for the sake of getting rid of noise. At the risk of sounding like a broken record though, look to a good third-party RAW converter to get the most from the 50D's images.
In terms of color, we certainly found nothing to complain about. Colors were vibrant without seeming overdone, and hues were very true to the originals.
Remember that we're holding digital SLRs like the Canon 50D to a slightly higher standard with these printed results than we do a point-and-shoot digital camera.
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 studio printer, and on the Canon iP5200 here in the office. (See the Canon Pixma Pro9000 review for details on that model.)