Nikon D5200 High ISO Noise Reduction
The Nikon D5200's four noise-reduction settings ("High, "Normal", "Low" and "Off") provide good flexibility in choosing how you want to make the trade-off between subject detail and noise levels. The Nikon D5200 user manual doesn't say when High ISO NR kicks in, so we've included crops from the base ISO in the tables below. The manual does however say that the "Off" setting still applies NR at ISO 1,600 and higher, though at a lower strength than the "Low" setting.
See for yourself how the Nikon D5200's "Normal", "Low" and "Off" High ISO NR settings compare to RAW without noise reduction under daylight-balanced lighting. (Note that these RAW images have no sharpening applied, so they look softer than camera JPEGs at low ISOs.) Click on any of the crops below to see the corresponding full-sized image.
The Nikon D5200's "Normal" High ISO NR setting provides a good tradeoff between noise and detail at lower ISOs to our eye, but we'd probably shoot with lower settings at higher ISOs and reduce noise ourselves in post-processing (or just shoot RAW). It's interesting that the camera does such a good job with the subtle contrast in the red-leaf swatch at low ISOs that it looks much better than the ACR converted RAW file, though the pleasing rendering of that fabric has been trademark of Nikons for years. It's also interesting that the camera sometimes produces a yellow cast with certain noise reduction settings at some higher ISOs (all shots here were taken with manual white balance), while the converted RAW files are more consistent in terms of color balance.