Canon 70D High ISO NR
Canon 70D High ISO Noise Reduction
The Canon 70D's four noise-reduction settings ("High, "Standard", "Low" and "Off") provide good flexibility in choosing how you want to make the trade-off between subject detail and noise levels. Since the Canon 70D user manual states noise reduction is applied at all ISOs, we've included crops from the base ISO below.
See for yourself how the Canon 70D's "Standard", "Low" and "Off" High ISO NR settings compare to RAW without noise reduction under daylight-balanced lighting. (Note that these RAW images also have no sharpening applied, so they're a little softer than camera JPEGs at low ISOs.) Click on any of the crops below to see the corresponding full-sized image.
The Canon 70D's default "Standard" High ISO NR setting provides a good tradeoff between noise and detail at low to moderate ISOs, but it struggles to maintain the contrast detail at higher ISOs, especially in our red-leaf fabric (as many cameras do). We'd probably shoot with lower settings at higher ISOs and reduce noise ourselves with post-processing (or just shoot RAW). Note how the "Off" setting doesn't disable noise reduction entirely even at low ISOs, and that the "Low" setting does a pretty good job suppressing chrominance noise while leaving more luminance noise (and more detail) than the default "Standard" setting.
Also note there is a "High" setting (not shown), as well as a Multi Shot Noise Reduction mode that captures, aligns and averages four images for even lower noise with better detail, however we did not test that mode in the lab.