Canon EOS 50D

Noise
Whenever you take a photograph, especially using a high ISO, you will notice semi-random areas of static across the entire image, especially in regions of flat color. This speckling worsens because of the increased sensitivity at these higher settings, so small fluctuations in light level and photonic activity get recorded as static on the image. Noise won't be very obvious if you're just shooting low resolution photos for the Internet, or for small prints, but once you get into larger file sizes, it's far more noticeable. Seeing as the 50D shoots images large enough to print 15"x10" at 300 pixels per inch, image noise can definitely be a noticeable problem, especially if you use the expanded ISO range (up to ISO 12800).

To test the levels of noise produced by the camera, we shoot a well lit Gretag Macbeth chart at every available ISO, including automatic, and run the resulting image through Imatest, which can tell us the amount of noise produced. The 50D has an extended ISO range, which approximates ISO 6400 and 12800, and while we did test at these levels, we didn't score based on them. We also run all these tests using all levels of High ISO noise reduction, to test just effective these utilities are.

Noise – Manual ISO (13.07)
With noise reduction turned off, noise levels peaked at 2.7% at ISO 3200, but reached up to 5% once we extended the ISO to 12800. At the lower end, these are pretty good results, and shooting below ISO 800 will keep noise levels below 1.5%. The 50D offers three levels of high ISO noise reduction: low, normal and high. While set on high, noise levels are reduced significantly. At ISO 3200, this reduction technology lowers the noise levels to 1.2% and at 12800 the noise level is 2.8%. As you can see, using the reduction tools can dramatically lower the amount of static in the image, but the downside is that you lose a small amount of color accuracy and detail as a price.

Since we score based on the best result from all the noise reduction settings, the 50D's very effective noise reduction setting netted a good score for this section.

Auto Noise (6.89)
Our automatic noise test isn't solely a measure of noise levels, but also of how smart the camera is when left to its own devices. We shoot the well-lit Gretag Macbeth chart with the ISO set to automatic, and look at what level the camera decides is appropriate. The lighting setup is bright enough that ISO 100 or 200 would be appropriate, and would result in a much higher score. The 50D, in its computer-ish wisdom, decided to shoot at ISO 400. This, coupled with generally low level of image noise, resulted in a pretty good score for the camera.

Low Light (8.80)
How well a camera performs in poor lighting conditions is of utmost importance, especially if you're planning on shooting in the evenings and at night. We ran the 50D through two sets of tests based on less-than-ideal conditions. The first involved photographing our Gretag Macbeth chart from 60 lux (approximately standard indoor lighting) down to the minuscule 5 lux (the light of a single candle) at ISO 1600, using all levels of high ISO noise reduction, and analyzing the resulting images for color accuracy using Imatest.

The 50D fared relatively well in these low light situations, keeping noise levels about 1.6% without noise reduction, and below 1% with the high ISO noise reduction cranked all the way up. The color accuracy was a bit below average, but the camera maintained a similar level of accuracy across all the light levels. Regardless of how dark a situation you're shooting in, you should be able to expect approximately the same level of color accuracy and saturation from the 50D.

The second round of low light tests involved photographing the same Gretag Macbeth color chart under 30 lux, but this time shooting exposure lengths from 1 second to 30 seconds, at ISO 400. This test is also run with long exposure noise reduction both on and off. The resulting images are run through Imatest to check for color accuracy and noise levels.

As you can see from the graph above, the long exposure noise reduction did next to nothing for noise levels. Regardless, noise levels were low, starting at 1.2% and working their way down to just under 1%. The 50D did significantly better on the long exposure test than on the low light, which points to the Canon as a good camera for photography that requires a significant amount of exposure time, such as photographing night scenes.

Canon EOS-50D Low Light Scores

The slightly below average score for low light performance coupled with a slightly above average result for long exposure, averages out to a middling result. Once again, we see the 50D being overtaken by its predecessor, the 40D, as well as the much less expensive XSi. It did outperform the Nikon D90, but it's still not an overly impressive result, a feeling we've had with a number of these tests.

Still Life
To show you how high ISOs can alter image brightness and noise levels in vaguely typical conditions, we've taken the liberty of photographing our loving mannequin couple, as well as Rosie the Riveter and her friends, at every ISO setting. Click on the images below to see the large version, but beware: at 15 megapixels they're large files, and liable to take a long time to load.

Color and Resolution	Page 4 of 15		Speed and Timing
Canon EOS 50D Digital Camera Review Navigation
Intro	Physical Tour	Color and Resolution	Noise and Video
Speed and Timing	Components	Design / Layout	Modes
Control Options	Image Parameters	Connectivity / Extras	Overall Impressions
Conclusion	Sample Photos	Specs / Ratings