If you record video you will never be able to record all the information. In addition to digital image compression, you also lose a large part of the spectrum from the available light.
That is not always clearly visible, you see it especially in situations with high contrast in the lighting. Then filming with a LOG Gamma profile can offer the solution.
What is LOG Gamma?
The term LOG comes from a logarithmic curve. In a normal shot, 100% would be white, 0% would be black and gray would be 50%. With a LOG, white is 85% gray, gray is 63% and black is 22% gray.
As a result, you get an image with very little contrast, as if you were looking through a light layer of fog.
It doesn’t look attractive as a raw recording, but the logarithmic curve allows you to record a lot more of the gamma spectrum.
What do you use LOG for?
If you edit directly from the camera to the end result, filming in LOG is of no use. You get a faded image that no one will like.
On the other hand, material shot in LOG format is ideal for fine-tuning in the color correction process and also has a lot of detail in the brightness.
Because you have much more dynamic range at your disposal, you will lose less detail during color correction. Filming with a LOG profile is only of value if the image has a high contrast and brightness.
To give an example: With a standard exposed studio scene or chroma-key it is better to film with a standard profile than an S-Log2/S-Log3 profile.
How do you record in LOG?
A number of manufacturers give you the option to film in LOG on a number of (high-end) models.
Not every camera uses the same LOG values. Sony calls it S-Log, Panasonic calls it V-Log, Canon calls it C-Log, ARRI also has its own profile.
To assist you, there are several LUTs with profiles for various cameras that make editing and color correction easier. Note that exposing a Log profile works differently than a standard (REC-709) profile.
With S-Log, for example, you can overexpose 1-2 stops to get a much better image (less noise) afterwards in post-production.
The correct way to expose a LOG profile depends on the brand, this information can be found on the camera manufacturer’s website.
Check out some of our favorite LUT profiles here
If you want to get the most out of your recordings, filming in LOG format is the best choice. You have to be prepared to correct the image afterwards, which obviously takes time.
It can certainly have added value for a (short) film, video clip or commercial. With a studio recording or news report it might be better to omit it and film in a standard profile.