Log Video

Log video uses a gamma curve that allocates recorded data non-linearly across the tonal range. Instead of a standard gamma curve that produces a viewable image directly from the camera, log gamma compresses highlights and shadows into the recorded signal. The result is a flat, desaturated image that looks incorrect straight from the camera but retains more information in bright and dark areas than a standard profile would. The preserved tonal range gives more flexibility when colour grading the footage in post-production.

Log recording is most beneficial in high-contrast shooting situations where both highlights and shadows must be preserved. Outdoor interviews with sky in background, scenes with mixed artificial and natural lighting, and landscape footage with exposed sky and shaded ground are all situations where log recording retains detail that standard profiles would clip. For controlled indoor shooting or fast-turnaround work where post-production grading is not planned, the added workflow step of grading log footage may not be worthwhile.

M43 cameras support log video through two formats: Panasonic's V-Log L on GH6, GH7, and G9 II bodies, and OM System's OM-Log 400 on OM-1 and OM-1 Mark II bodies. Both use a flat gamma curve designed for grading and require a LUT (look-up table) or manual grade to convert to a viewable colour space for delivery. Log footage delivered without grading appears flat and undersaturated by design.

Log video produces larger file sizes than standard profiles at the same resolution and frame rate, because the flat gamma requires higher bitrates to avoid banding and compression artefacts in the low-contrast regions. Log recording also requires faster memory cards and more storage than standard profiles. Monitoring log footage on set requires either applying a monitor LUT in the camera's display settings or accepting that the on-set image will look flat until graded in post.