|Image quality test on our DIWA Lab
Canon's claim that the EOS 50D will show an equal or even better signal/noise ratio despite the 50% increase of the amount of Megapixels, asks for testing in laboratory conditions. The new sensor technique with innovative build-up of pixels, combined with the new DIGIC 4 processor, should stand for a new standard in image quality in this high resolution segment.
Canon EOS 50D color reproduction
Color reproduction of the Canon EOS 50D is accurate and is equal to the Gretag Macbeth Color Checker up to and including 1600 ISO. High ISO from 1600 to 12800 ISO deviates only marginally, so the conclusion is that the Canon EOS 50D produces a beautiful and extremely precise color reproduction. Compared to the EOS 40D, the 50D even shows improvement. The EOS 40D test showed a constant graph over the entire sensor sensitivity, however, the reproduction deviated a lot more from the Gretag Macbeth Color Checker. Measurements for white balance prove that the Canon EOS 50D is very well able to carry out a manually set white balance up to and including 6400 ISO, very precisely to excellently. At 12800 ISO, a reasonable result is measured. In comparison to the 40D, the 50D is improved again, although this was only slightly noticeable in the Lab.
Measuring the sensor sensitivity
The fact that we are dealing with a different sensor in the Canon 50D may be clear. It's interesting to measure the actual sensitivity of the sensor. For the actual sensitivity of the 40D was significantly higher than the specified values. And although within the average margins of 25%, the EOS 40D test showed that 200-3200 ISO was actually an average of 22.4% higher than specified. First thing that was obvious when measuring sensor sensitivity of the Canon EOS 50D was the fact that the specified values were almost identical to the actual sensitivity. ISO 200 - 3200 only deviated a mere 1.6% from the specified values. The exception is ISO 100 with a 26% higher sensitivity and 6400 and 12800 ISO that are an average of 21% higher than specified.
Noise values of the Canon EOS 50D
The noise values of the Canon EOS 50D are excellent. Even more astonishing when we consider the 50% increase of megapixels compared to the 40D. Canon's claim that the high resolution does not have a negative effect on the signal/noise ratio, stands strong and is completely true.
|From the Lab test it is clear that the Canon 50D even delivers improved values in particular at the high ISOs. Striking is the result for 100 and 200 ISO, where the EOS 50D is able to achieve an improved, albeit a tiny improvement, it is still an improvement, signal/noise ratio. As for figures, it is an improvement of 4%. The differences for 400 and 800 ISO are nearly equal yet the 50D wins by a nose. As for ISO 1600 and 3200, the EOS 50D is obviously a lot better than the 40D with respectively 8 and 13% of improved signal/noise ratio. The new sensor technique in combination with the DIGIC 4 processor is the strong trump of the Canon EOS 50D.
Dynamic range is excellent
The EOS DSLR is usually confident about the dynamic range and does generally not have to worry about it. The Canon EOS 50D again proves this. The camera performs excellently over the range up to 6400 ISO, with just the 12800 ISO encountering trouble to follow correctly. The EOS 50D shows nice values that reproduce difficult light and dark areas in a picture excellently at which preservation of detail stands out. This quality in combination with 15 Megapixel of resolution is perfect to make full use of the possibilities of a crop.
Canon 50D test combined with the EF-S 18-200mm lens
In the DIWA Lab, the Canon EOS 50D was tested in combination with the EF-S 18-200mm f/3.5-5.6 IS, a lens with a popular all-round range. As for sharpness in the centre, this lens performs up to and including f/22 excellently to good for all focal points. It's not until f/32 and f/36 that blur is clearly visible however; this kind of aperture would not be the ideal aperture to work with for daily use. The sharpness towards the edges is poor. At aperture f/8 and f11 and focal points 18 and 80, excellent sharpness is achieved. The remaining focal points and apertures show visible blur which is a disappointing performance.
Canon EF-S 18-200mm f/3.5-5.6 IS lens
The Canon EF-S 18-200mm f/3.5-5.6 IS lens suffers from visible distortion (+1.38%) only at 18mm wide angle over the entire aperture range. The remaining focal points are all safe. The Canon 18-200 lens does suffer from chromatic aberration to a large extent. In particular wide angle and telephoto suffer the most, and in practice this means a lot of purple fringing around the edges of a subject with a lot of contrast. Canon should be able to eliminate this effect via the software in the camera like Nikon does. The performance of the lens is perfect as for vignetting. This is not visible with the naked eye, it is only slightly detectable in the lab.