Canon EOS 50D

Overall, through our extensive gamut of testing, the 50D performed well, but not exceptionally well. In general it scored slightly worse than it's predecessor, the 40D, but about on par with the Nikon D90. It is surprising that the Canon Rebel XSi, a much much more affordable camera, consistently scored as well as, if not better than, the 50D.

Color (8.67)
To test the camera's ability accurately record color, we photograph the Gretag Macbeth color chart, which is composed of carefully defined and consistently reproduced colors. This photo is then run through the image analysis application Imatest, which can judge how much the captured image differes from the true chart color. Keep in mind, this test is to see how accurate the colors are, and will penalize cameras that make them overly bright or saturated. While having extreme colors may make for exciting pictures, they actually lose information for editing, and aren't as close to reality. The chart is photographed at every available ISO under bright 1700-lux illumination.

Canon has a series of what are known as Picture Styles, which alter the color, brightness, sharpness and saturation of an image. After extensive testing, we found that the Faithful setting provided the best results, and so tested on this setting.

The chart below shows how close the captured color (the outer rectangle) is to the luminance-corrected true color (inner square) and the original chart color (inset rectangle).

The analyzed Gretag Macbeth color chart

The graph below expresses the same information, but in a slightly more readable manner. The ideal color is represented by the square, the actual color is in the circle, and the hue and saturation error is shown by the distance and direction of the line. So the longer the line, the less accurate the color.

The 50D did very well reproducing blues and pinks

Regardless of this fact, we were still hoping for a slightly better score out of the 50D, as Canon cameras have a reputation for good color accuracy.

Resolution (11.59)
Our resolution test is more than just a measure of megapixels. Rather, we look at how adept the camera is at recording fine details. A high resolution score means that your camera can capture a large amount of information, without undersharpening or oversharpening the picture. We photograph a standardized resolution chart, evenly lit to 1700 lux, from a number of distances, and at every available aperture. The resulting pictures are analyzed through Imatest, which outputs a measure of resolution as line widths per pixel height (lw/ph), which is a count of the maximum number of distinct alternating black and white lines.

An actual-size section of the industry-standard resolution chart shot with the 50D

At its best, the 50D captured 1938 lw/ph horizontally with approximately 7% undersharpening and 2004 lw/ph vertically with 9.3% undersharpening. This produced a good score for the camera, which would have been even better if not for the noticeable undersharpening. Once again, this is probably a conscious decision from Canon, as it's far easier to sharpen an undersharpened image than it is to unsharpen one that's oversharpened (try saying that five times fast!). This puts more control in the hand of the photographer, rather than trying to get the prettiest looking picture directly from the camera.

White Balance (9.36)
A camera's white balance system accommodates the different color temperatures provided by different light sources. For instance, a tungsten light will produce a noticeably more orange hue than natural sunlight, and a fluorescenct bulb will be a bit bluer. Our brains can easily account for this, and make a white object seem white, regardless of the light cast. A camera, contrarily, has to digitally adjust to deal with this difference between how things actually look, and how we want them to. We tested the 50D's white balancing abilities in two ways, first using the automatic white balance setting under flash, fluorescent, indirect daylight and tungsten lights. We then also tested the presets for each of those light sources, which are the 50D's built in settings for each source, and ran the resulting images through Imatest to test for color accuracy. Keep in mind, the charts below are highly exaggerated: you won't see this level of error in your actual photographs.

Auto White Balance(12.15)
The automatic white balance performed very well for two of the illumination sources, and less so for the other two. The flash and fluorescent results were both exemplary, and showed a result that was very close to reality. For daylight illumination, it was below average, but not abysmal. The 50D really struggled with tungsten illumination, though, a common problem, but unfortunate as tungsten lights are used for most indoor lighting situations.

Preset (6.58)
The preset white balance settings fared a little worse for flash and shade; significantly better for the tungsten, and much, much worse for fluorescent. This is most likely due to the fact that fluorescent lights can actually represent quite a wide variety of color temperatures, which is why many camera have two or three fluorescent settings. The 50D, unfortunately, only has one, and so did not fare well in this phase of the testing. Once again, remember, the errors shown below are exaggerated, and far beyond what you would actually see.

Exaggerated White Balance Errors (Presets)

Flash Preset WB - Flash Illumination

Fluorescent Preset WB - Fluorescent Illumination

Cloudy Daylight preset WB - Daylight illumination

Tungsten preset WB - Tungsten illumination

The 50D scored above average on this test, mostly on the strength of it's automatic setting. Based on the result we've seen in this test, unless you're shooting under tungsten, you'll do just fine using the automatic setting. Even beyond the automatic and presets, the 50D also has the option to manually white balance from a stored image white or grey image, enter the Kelvin value of a specific lighting setup, as well as amber/blue and green/magenta shifting for fine tuning. With this bevy of settings, you should be able to setup the correct white balance for nigh on any situations, assuming you have the time to select the proper options.