What is LOG?
LOG is a video capture format that that maximizes the tonal range pulled from the camera’s image sensor. It allows you to see your image as the sensor sees it, and in the right hands, it can allow you to unlock your camera’s full image-capturing potential. High end models of Canon, Sony, and Arri cameras commonly shoot footage in LOG profiles because the format offers the most latitude when color correcting and color grading in post production. LOG’s wide tonal range is preferable over REC 709 when it comes to color grading.
If you look at initial LOG footage out of a camera, it appears flat and desaturated. You wouldn’t want to present it to a viewing audience as is. LOG was made with the intention of being color graded. The flat, muddy-looking format offers a wide tonal range for color manipulation. When grading LOG footage, colorists have ample space to work with highlight and shadow detail.
LOG VS Raw
LOG is sometimes confused with raw video. It’s a common thought, but LOG is not raw video. LOG is viewable, editable video. It also has image information, like white balance, assigned to its files. Raw, on the other hand, is direct sensor data. It has no color information assigned to it, and it needs to processed in order to be viewed or edited.
Why you should use LOG
Log offers greater possibilities in color grading. The wide tonal range gives the colorist a large field to work with. LOG is particularly beneficial because it preserves highlights and shadow, which are often clipped in REC 709. Clipping means there is no way to save parts of the image that are too bright or too dark.
LOG and LUTs
LOG can be graded without any use of LUTs, however LUTs can be applied to bring the profile into the REC 709 color space. This could beneficial, if you want a quick estimate of how the image will look when its displayed. LUTs can also add style to the image. A LUT can quickly provide you with a sharp look or be the starting point for the unique grade you envision.
LOG and Compression
LOG can be compressed or uncompressed. Whether or not it is compressed depends on the camera that’s capturing the video. Professional cameras often give the option for compressed or uncompressed, while lower-lever cameras automatically compress LOG video.
Cameras and their LOG profiles:
Arri cameras: Log C
Cannon: C Log
Sony: S-log, S-log 2, S-log 3
Black Magic Design: Film mode