Basic color control in Silverstack

Silverstack’s color processing enables you to create thumbnails, playback clips and transcode dailies with a look. This article introduces you to the fundamentals of color processing in Silverstack, including information on how to create looks and work with LUTs. In general, a look stores all relevant information to define the color appearance of a clip in Silverstack.

To learn more about color in Silverstack, we encourage you to read the articles about grading modes, custom RAW development and the look library.

1. Look Source#

Each clip has a “Look Source” that defines its color processing. This option can be found in the associated look section of the general info.

Tip: You can set a default look source when ingesting clips by selecting the appropriate option in the “Import Options” section of the registration activity in the workflow configuration window.

A look source can have the following options:

None
No color processing is applied and the clip won’t show any look

From File
For supported formats, the look information can be extracted directly from the file metadata (e.g., for ARRI Alexa clips). In case there is no embedded look, Silverstack directly applies the default Log to Rec.709 conversion.

Preset
Select a LUT transform from the available LUT presets integrated in Silverstack.

User selected LUT
Allows you to load a custom LUT to be applied to the clip.

Custom Look
Creates a custom look with node based grade controls. This feature allows users to display “Log” clips in a different color space by applying preset LUTs, user predefined custom 3D LUTs or color metadata (looks) embedded in clips (for selected formats1).

Tip: For more information about custom RAW processing and decoding color spaces, please view our article about custom RAW development.

Matched Look
When looks from Livegrade have been matched to clips via look matching, a new look source with name “Matched Look” becomes available. You can start and customize the matched look by pressing “Edit Look…” in the color panel. You can always return to the matched look by setting the look source back to the matched look.

1.1 How to apply and manage custom LUTs#

One of Silverstack’s color control features is the ability to apply custom LUTs to one or multiple clips. Users can load custom 3D LUTs generated by other software applications – such as LiveGrade Pro. When a custom LUT is used, Silverstack displays thumbnails and playback with that look applied. Transcoding of the clips with that LUT is also possible.

Custom LUTs loading

The supported 3D LUT formats are:

.cube (32x32x32, 33x33x33 and 65x65x65)
.3dl (32x32x32)

In order to load them, just set the look source to “User-defined LUT…” and click on the Load LUT File… button. Then navigate via the open dialog to the LUT file, select and open it. Finally, click on the Apply button apply the LUT to the clip.

1.2 Setting a look for transcoding#

When transcoding clips, you can choose which look should be applied to the clips. You can change the look source settings in the transcoding preset panel.

1 The selected formats with Look Metadata reading are Alexa ProRes, ARRIRAW, Amira ProRes, RED Raw and Panasonic Varicam 35. If no look metadata is embedded in the file, a default log-to-video conversion is chosen for the specific format (e.g. XAVC with S-Log).