For viewing directly on the set and for color correction in post, look up tables (LUTs) are used. A LUT transforms the signal to adjust the sensitivity and provide a correct monitor input. To download the proper LUT for your production, we created this page to sort the LUT you need from out of the many combinations that are available.

It is necessary to know what third party manufacturers you are working with, what LOG mode you are shooting in and exposure index (EI) you will be using.

The ARRI ALEXA can output the following formats:

Video (ITU 709) as 4:2:2 or 4:4:4 SDI
Video data produces a directly viewable picture on a standard video monitor. The data is exposure-compensated, tone-mapped, and corrected for the assumed gamma of the monitor (2.4).

Log C as 4:4:4 SDI
Log C data is most commonly used when data is processed in a similar way as scanned negative film. The data is exposure-compensated. Each exposure stop is represented by roughly the same number of code values. The data is neither tone-mapped nor corrected for the monitor gamma. One can view the data in a standard monitor but the image will look "flat."

Many who use Log C mode of the ALEXA will want to work with the recorded images in a DI workflow. That means they want to view and color correnct the images using aprint film emulation LUT as they do with images scanned from a engative. While Log C mode in the ALEXA produces images having a gradation (or "gamma") like film scans, the colors will be different. As we did not want to bake any transform into the data, the current Log C mode of the ALEXA could be called "log-raw" mode because it gives you the Log C transform of the sensor RGB data. This mode elaves open all options in post. The overall look of the images, however, will be desaturated.

This download includes a LUT for this "log-raw" that will help the colorist create more natural colored images. The complete LUT package contains all LUTs necessary for converting ALEXA images between Linear, Log C and Video.

To download LUTs for ALEXA, sign in or registration is required.