10-bit

Bit depth in video refers to how many discrete tonal values can be recorded per colour channel. An 8-bit recording stores 256 levels per channel (red, green, blue), for a total of approximately 16.7 million possible colours. A 10-bit recording stores 1,024 levels per channel, for approximately 1.07 billion possible colours. The difference is most visible not in the total colour gamut but in the smoothness of gradients and the ability to recover detail in compressed highlights and shadows during colour grading.

When footage is graded — colour corrected and given a look in post-production — the tonal values are mathematically redistributed. In 8-bit footage, this redistribution can expose the limited number of available values as visible stepping or banding in smooth gradients, particularly in skies, skin tones, and out-of-focus backgrounds. In 10-bit footage, the additional 768 values per channel provide enough resolution that the same grade produces smooth gradients without visible stepping. The improvement is most apparent in log-encoded footage, where the flat tonal curve compresses a wide dynamic range into the available values; more values means finer gradation in the recovered image.

In M43, 10-bit internal video is available on the Panasonic GH7, G9 II, GH6, and GH5 II in specific recording modes. The Blackmagic Pocket Cinema Camera 4K records in Blackmagic RAW, which exceeds 10-bit in colour depth. The Panasonic G97 and earlier mid-range M43 bodies record in 8-bit internally. HDMI output on some 8-bit bodies can provide a 10-bit signal to an external recorder, though this is less convenient than internal 10-bit recording.