Panasonic GX8 High ISO NR
Panasonic GX8 Noise Reduction
Like other Panasonic mirrorless cameras, the GX8 offers no fewer than 11(!) noise reduction levels, offering very fine granularity on noise reduction strength, however there doesn't appear to be a way to assign different NR levels to specific ISO ranges as we've seen on some cameras. The Panasonic GX8 user manual doesn't say when noise reduction kicks in, so we've included crops from the entire range of ISOs in the tables below.
See for yourself how the Panasonic GX8's default and -5 (lowest) noise reduction 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 Panasonic GX8's default noise reduction setting provides a good tradeoff between noise and detail at lower ISOs to our eye, but we'd shoot with the lowest setting at higher ISOs and reduce noise ourselves in post-processing (or just shoot RAW). As you can see, the GX8 already applies noise reduction at its lowest (extended) ISO of 100. At the other end of the ISO range, you can see that the GX8 is quite effective at reducing noise, but of course at a cost to fine detail. Also notice that noise reduction impacts fine detail in our difficult red-leaf swatch already at moderately low ISOs.