Sony RX1 High ISO NR
Sony RX1 Noise Reduction
The Sony RX1 offers three high ISO noise reduction settings: "Off," "Low," and "Normal," with Normal being the default. The user manual does not say at what ISO high ISO noise reduction kicks in, so we've included crops starting from ISO 50. There's also a separate Multi-frame Noise Reduction option which combines several frames to average out noise.
See for yourself how the four noise reduction settings work under daylight-balanced lighting. Click on any of the crops below to see the corresponding full-sized image.
It appears the Sony RX1 starts to apply noticeable High ISO Noise Reduction at ISO 400, as you can see the varying levels of noise reduction applied from then on. Sony says noise reduction is not applied to RAW files.
Clearly, the Off setting is not really off, as is often the case. It's also interesting that the Off setting smears our red leaf cloth much more than the Low and Normal settings, though chroma and luminance noise is higher. This appears to be the same bug we've seen in other Sonys, including the SLT-A99. The Low setting leaves a little more luminance noise than the Normal setting. Overall, the Normal setting provides a pretty good balance between noise and detail, but you'll want to shoot in RAW mode for maximum control over the noise versus detail trade-off.
Multi-frame Noise Reduction is not available at ISO 50, but extends ISO range to 102,400. It produces the cleanest images, however detail is a little soft even at low ISOs. Note that Multi-frame Noise Reduction is not available in RAW or RAW+JPEG modes, and the flash, D-Range Optimizer and Auto HDR cannot be used.