Panasonic GM1 High ISO NR
Panasonic GM1 High ISO Noise Reduction
The Panasonic GM1 offers eleven(!) settings for noise reduction, ranging from -5 to +5. The user manual doesn't state at which ISO noise reduction kicks in, so we've started with ISO 125 (extended) to find out.
See for yourself how the Panasonic GM1's "0" (default) and "-5" (lowest) 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 are softer than camera JPEGs at low ISOs.) Click on any of the crops below to see the corresponding full-sized image.
As you can see, even the lowest High ISO NR setting of -5 applies noise suppression at all ISOs. The -5 setting does apply less luminance noise suppression than the default, but as you can see, chroma noise is still fairly aggressively suppressed at both settings. Also note the signs of horizontal "streaking" near the bottom of the bottle crops at the highest ISOs, we think caused by the GM1's electronic shutter at exposures shorter than 1/500s. You can read more about the GM1's electronic shutter artifacts here.