Canon EOS T2i High ISO Noise Reduction
The Canon T2i offers four settings for noise reduction: Disable, Low, Standard and Strong, and NR is applied at all ISOs. Its different noise-reduction settings also allow you quite a bit of flexibility in choosing how you want to make the trade-off between subject detail and noise levels. It's not clear that the "Disable" setting truly eliminates the noise processing altogether, but it is true that it leaves a lot of fine/subtle subject detail there for you to work with. The combination of shooting with NR "Disabled" and using a good noise-filtering program after the fact can produce very clean images with lots of fine detail in them.
See for yourself how the noise reduction works under both daylight and tungsten-balanced lighting. Click on any of the crops below to see the corresponding full-sized image.
The above crops show the effects of the four levels of high ISO noise reduction, under our studio HMI lighting we use to simulate daylight. The Standard setting strikes a good balance between noise and detail, however subtle detail in the red cloth swatch already suffers quite a bit at ISO 1,600.
How does the Canon T2i compare with competing models? See the following table which compares at the default Noise Reduction setting.
Here, the Nikon D90 performs the best at higher ISOs, but also has the lowest resolution and therefore the largest photosites of the group. It also shows more sharpening artifacts, which can lead to rough edges. Canon T2i images are smoother looking at high ISOs, and there's no denying the extra resolution the T2i offers over the D90. The Canon T2i performs slightly better than its more expensive sibling, the Canon EOS 7D, and quite a bit better than the Pentax K-7.
Here's a comparison with some less expensive models:
Here, the Canon T2i does well against its less expensive sibling, the Canon T1i, despite having smaller photosites. The Nikon D5000 still shows more detail in the red leaf fabric, but tends to show more sharpening artifacts, and a bit more chroma noise in the shadows. The Pentax K-x also struggles with red leaf detail at ISO 1,600 and above, but generally delivers pretty clean images if also a bit oversharpened.
Keep in mind these comparisons are at default settings, and that each manufacturer has its own definition of "normal" noise reduction. We'll be adding a RAW crop page once our standard RAW converter (dcraw) supports the T2i. Converting from RAW eliminates most if not all of the differences due to in-camera processing, and will give a much better indication of how the sensors compare in terms of noise performance.