Canon's EOS 550D offers a more affordable alternative to the top-of-the-range APS-C-format EOS 7D, but can it compete against the slightly more mature Nikon D90? We find out in our test: Canon EOS 550D vs Nikon D90
Like the Canon EOS 7D, the Canon EOS 550D has an APS-C-sized CMOS sensor with 18 million effective pixels.
The Nikon D90’s APS-C-sized sensor, however, has a pixel count of 12.3 million. This is a substantial difference of almost six million pixels, which has a significant impact upon the size of prints that can be made.
As they are made up of 5184×3456 pixels, images from the Canon EOS 550D generate 43.89×29.26cm (17.28×11.52in) prints at 300ppi. In comparison, the 4288×2848-pixel output of the D90 translates into 36.31×24.11cm (14.3×9.49in) 300ppi prints. So if A2 (59.4x42cm) prints are the aim, the image resolution must drop to 221ppi for images from the EOS 550D and 183ppi for the D90.
The term ‘APS-C-sized’ means slightly different things to Canon and Nikon, so although both cameras feature ‘APS-C’-format CMOS sensors, the sensor in the Canon EOS 550D is 22.3×14.9mm while the device in the Nikon D90 is slightly larger and measures 23.6×15.8mm. One consequence is that the EOS 550D, like other Canon APS-C-format cameras, has a focal length magnification factor of 1.6x, whereas the D90 effectively magnifies the focal length by 1.5x.
Nikon maintains that sticking with a pixel count of 12 million enables the photosites on the sensor to be larger, so they generate a stronger signal that requires less amplification. Keeping amplification levels down helps to reduce the amount of noise introduced so images are cleaner.
As the Canon camera has a considerably higher pixel count than the D90, we can deduce that the photodiodes in the Nikon camera are significantly larger than the EOS 550D’s. This should give the D90 a head start in the image quality stakes, but we have seen significant strides made in noise control over the past 18 months or so and this should boost the performance of the EOS 550D.
One of the D90’s key selling points at its launch was that it has the same sensor and Expeed image processor as the D300. The sensor and processor combine to enable a sensitivity range of ISO 200-3200 that may be expanded to ISO 100-6400, and a maximum continuous shooting rate of 4.5fps that continues for around 100 of the highest-quality JPEG images or 10 raw files (or seven simultaneous raw and JPEG images) when a 30MB/s SD card such as a SanDisk Extreme III SD card is installed.
The EOS 550D has a lower maximum continuous shooting speed of 3.7fps, and Canon claims a conservative burst depth of 34 high-quality JPEG images or six raw files, but with the Extreme III SD card installed I was able to shoot 300 high-quality JPEGs or seven raw files.
In practice, the 100-image burst depth of the D90 is likely to be more than enough for most occasions, and the extra 0.8fps could make a difference to sports enthusiasts trying to capture fast-moving action.
Canon included wireless flash technology in a DSLR for the first time with the EOS 7D. and although the EOS 550D has much in common with this camera it has unfortunately not been blessed with the ability to control an external flashgun wirelessly. The Nikon D90, however, can.