Setting up ARRI cameras

Livegrade comes with support for remote look control and metadata over Ethernet of ARRI cameras. This includes the following ARRI Alexa camera types:

ARRI cameras using ALF2 looks:

• ARRI Alexa SXT
• ARRI Alexa Mini
• ARRI Amira
• ARRI Alexa 65
• ARRI Alexa LF
• ARRI Alexa Mini LF

ARRI cameras using ALF4 looks:

• ARRI Alexa 35
• ARRI Alexa 35 Xtreme
• ARRI Alexa 265

With this feature set you can send looks to be applied in an ARRI camera. This has two main benefits:

• Live-graded image output directly from the camera: Each output of the camera – including the viewfinder – can show the live-graded image.
• Look metadata stored together with OCF: Without any additional steps needed, the looks will be saved in the file header of each recorded clip. Anyone in the post production pipeline who gets in touch with the material has the opportunity to reveal the look which was set live on set.
• Comprehensive metadata read-out: Adding the camera as look device to your slot allows you to select the camera as metadata source for your slot metadata.

Preconditions for remote look control#

• Editable Look selected in the camera: Before grading an ARRI camera, make sure that you have selected an editable look (e.g. through duplicating the “Default” look) in your camera.
• Network connection: In order to exchange look information with Livegrade, the camera needs to have a working network connection with the computer where Livegrade is running.
• Enable CAP: To connect Livegrade to the camera you have to enable the Camera Access Protocol (CAP) in the ARRI camera’s menu at System -> Camera Access Protocol. You can also set a CAP Server password there to protect access to the camera.
• SDI out shows look: To output the graded look via the camera’s SDI out make sure that the processing of the used SDI port is set to “Look”.

Adding the ARRI camera as a device#

Once the camera is in the same network as your computer, you can add it to any input slot using the slot manager.

Open the slot manager

• by clicking on the Slot Manager symbol in the toolbar or
• via the menu: Livegrade > [Slot Manager…]

In the slot manager, click on the input you want to add the device to.

Within an input click on the + Add Device button in the Look Devices section to add your ARRI camera to the slot.

As ARRI cameras use different look formats – ALF2 (e.g. ALEXA Mini) or ALF4 (e.g. ALEXA 35), you can either add an ARRI Camera (ALF2) or ARRI Camera (ALF4) device.

Configuring an ARRI camera#

• Host: enter the device’s IP address
• Password: enter the password for that camera as defined in the camera as CAP Server password before.
• Look Update: Choose how to update the look on the device.
  • Interactive
    • Adjustments of the look will be sent immediately to the device.
  • Manual Upload
    • Adjustments of the look will be sent on “Upload Look” actions. These actions are available as menu items (Slots > [Upload Look to Device(s)] menu), Toolbar button, Stream Deck and Tangent action
  • Off
    • only available for look devices with the possibility to provide a metadata stream, such as RED and ARRI ALF4 cameras
    • The look won’t be sent to the device.
• Frame Grab: Activate Continuously refresh frame grab to auto-refresh your slot’s preview image

Additional options for cameras using ALF4 looks#

The following Look Control options are only available for cameras which use ALF4 looks (e.g. Alexa 35 or Alexa 265).

• Look Control: choose how you would like to control the camera’s look
  • CDL + CMT:
    • The look will be sent as CDL and CMT to the camera.
    • DRTs will be set by the camera depending on the camera’s “SDI Color Space” setting.
  • DRT:
    • The look will be sent as DRT to the camera. CDL and CMT will be set to neutral.
    • Output Colorspace
      • Sets the output colorspace for the DRT.
      • If the output colorspace is set to an HDR colorspace, the look will be sent as DRT HDR. DRT SDR will be set neutral.
      • If the output colorspace is set to an SDR colorspace, the look will be sent as DRT SDR. DRT HDR will be set neutral.

ALF4 options with activated 2nd color pipeline#

If you enabled the 2nd color pipeline in Livegrade 7 (learn more about using dual pipeline looks for HDR/SDR dual monitoring workflows), you can use the options as follows:

• Look Control: choose how you would like to control the camera’s look
  • CDL + CMT:
    • The look of the chosen HDR or SDR pipeline will be sent as CDL and CMT to the camera.
    • DRTs will be set by the camera depending on the camera’s “SDI Color Space” setting.
    • Pipeline: choose whether the HDR or SDR pipeline should be sent to the the camera.
  • DRT:
    • The HDR look will be sent as DRT HDR to the camera.
    • The SDR look will be sent as DRT SDR to the camera.
    • CDL and CMT will be set to neutral.
    • Output Colorspace
      • Sets the output colorspace for the DRT HDR and DRT SDR.

Connecting to the camera#

Finally, click on Connect to add the device to the slot. After that the current look of the corresponding input slot will always be sent to the look device as long as the input slot is in Live mode.

Choosing the ARRI camera as metadata source#

Once you added an ARRI camera as look device to your slot, you can select it as metadata source so that Livegrade reads the camera metadata via the Ethernet connection to the camera instead of reading the metadata within the SDI stream or the frame grab coming from a LUT box.

To do so,

• In the slot manager, click on the slot you want to configure
• Check the “Look Devices” section and make sure that the ARRI camera was already added and is connected
• Scroll down to the “Image and Metadata” section
• Use the “Metadata Source” drop-down menu and select the ARRI camera

From now on, the auto-populated metadata in your slot will come from the camera.

• the “Image Source”, if you want the field to be populated via the slot’s configured image source
• the “Metadata Source”, if you want the field to be populated via the slot’s configured metadata source
• “User editable”, if you want to enter the data for this field manually

Following metadata fields can be received from the camera:

• Sensor FPS
• EI/ISO
• Shutter Angle
• White Balance
• Green Tint
• Lens Model
• Focal Length
• Focus Distance
• Cam. Model

Remote grading of ALF2 and ALF4 looks#

Since the underlying looks of the ARRI camera generations – from Alexa Mini to Alexa 35 Extreme – differ significantly, Livegrade also offers different possibilities to grade the looks of those cameras.

For this reason, we will now also differentiate between ALF2 and ALF4 in-camera grading in this article, since ALF2 and ALF4 are the underlying look formats which define the possibilites while using in-camera grading.

Grading an ARRI Camera with ALF2 looks#

As soon as you successfully have added the ARRI camera to one of your slots you can start live-grading using one of the following grading modes:

• CDL and LUT
• CDL Advanced

Livegrading an ARRI camera with an underlying ALF2 look basically means altering the certain look file remotely, which is currently loaded in the camera. So let’s take a look at ALF2 look files first before we move on with explaining what actually happens when grading the camera.

ALF2 Look Files#

ALF2 look files used in ALEV3 cameras (e.g. Alexa Mini, Alexa LF, Alexa Mini LF, Alexa 65, Alexa SXT, Amira) consist of

• CDL & Saturation

ASC-CDL and Saturation values

• Custom 3D-LUT

A single 3D-LUT file which contains creative look adjustments and a colorspace conversion, e.g. from LogC3 to Rec709

ALF2 Look File

Both parts of an ALF2 look can be adjusted by Livegrade as explained in the next chapter.

ALF2 look control#

When grading a slot with an attached ARRI camera, Livegrade adjusts the ALF2 look in the camera as follows:

• All CDL and Saturation nodes of your grade will be merged into one single ASC-CDL file and will be sent as such to the camera
• All Curves and LUTs – including your last LUT node which will be an output transform in most cases – of your grade will be merged into one single 3D LUT and will be sent as such to the camera

Grading an ALF2 look

The described behaviour works in the following grading modes:

• CDL and LUT
• CDL Advanced

To name your nodes accordingly to the ALF2 look specification, you can apply the ARRI ALF2 look template which is available in CDL Advanced grading mode and can be selected by pressing the Look Template button on the right side of the grading mode selector.

Look templates for CDL Advanced

Look template ARRI ALF2

Look template “ARRI ALF2”

Extracting the look#

Extracting the look from a clip that was recorded will then give you

• an ASC-CDL containing all CDL and Saturation adjustments in one set of values
• a 3D LUT containing all LUT and Curve adjustments combined in one single 3D LUT

Grading an ARRI Camera with ALF4 looks (e.g. Alexa 35)#

When adding an ALF4 camera such as ARRI Alexa 35 or 265 to one of your slots, you can choose between two ways to control the ALF4 look of the camera. This is done via the* Look Control *options found in the Add ARRI Camera (ALF4) dialog:

• CDL + CMT (default): This is the default way of controlling your ALF4 look via ARRI CAP Compatible grading mode. It sets the CDL and CMT part of the camera’s ALF4 look and leaves the DRTs untouched.
• DRT: This advanced way of in-camera grading allows you to send your whole look (including input and output transforms) as 3D LUT to the camera.

Depending on which option you choose, Livegrade will interact differently with the attached camera.

Before we go into the differences between CDL + CMT and DRT mode, we take a look at the structure of ALF4 looks first.

ALF4 Look Files#

ALF4 look files used by cameras such as Alexa 35 or Alexa 265 consist of

• CDL & Saturation: CDL and Saturation values
• CMT (Color Modification Transform): A 3D-LUT which contains creative LogC4 to LogC4 look adjustments
• DRT SDR: A 3D-LUT which contains the colorspace conversion to a certain target SDR colorspace (Rec.709 or Rec.2020)
• DRT HDR: A 3D-LUT which contains the colorspace conversion to a certain target HDR colorspace (Rec.2100 PQ or Rec.2100 HLG)

ALF4 Look Files

ALF4c files are looks which contain a custom color management with DRTs created by a user.

Depending on the *Look Control *mode you have chosen, Livegrade will adjust the individual parts of the ALF4 or ALF4c look differently.

CDL+CMT Look Control#

You can use this way of controlling your look to

• control an ALF4 look where the standard ARRI Color Management LUTs are used for the display rendering transforms
• control an ALF4c look created in the ARRI Reference tool where custom 3D LUTs are used for the display rendering transforms

Adding an ALF4 camera in CDL+CMT Mode#

After adding an ARRI camera using ALF4 with look control set to CDL+CMT, Livegrade will

• load the current look’s name from the camera into your Livegrade look’s name
• indicate a proper connection with a green light
  • If the connection process was not successful, please check your network and reconnect to the camera by removing the device from the slot and adding it again.

As soon as you successfully added the camera in CDL + CMT mode to one of your slots you can start live grading.

Grading with CDL+CMT Look Control#

Let’s take a look at what actually happens when grading an attached camera in CDL+CMT mode remotely:

• All CDL and Saturation nodes of your grade will be merged into one single ASC-CDL and will be sent as such to the camera
• All Curves and LUTs (except the last LUT node) of your grade will be merged into one single 3D LUT and will be sent as such to the camera
• The last LUT node won’t be sent to the camera. The camera will apply the display render transforms (DRT) internally in regard to the chosen colorspace of the camera’s SDI output.

Grading in CDL+CMT mode

The described behaviour works in the following grading modes:

• CDL and LUT
• CDL Advanced

To name your nodes accordingly to the ALF4 look specification, you can apply the ARRI ALF4(c) look template which is available in CDL Advanced grading mode and can be selected by pressing the Look Template button on the right side of the grading mode selector.

Look templates for CDL Advanced

Look template “ARRI ALF4(c)”

Look template “ARRI ALF4(c)”

Extracting the CDL + CMT look#

Extracting the look from a clip that was recorded will then give you

• an ASC-CDL containing all CDL and Saturation adjustments in one set of values
• a 3D LUT representing the CMT part which contains all LUT and Curve adjustments (except the last LUT node) combined in one single 3D LUT
• two 3D LUTs representing the DRT SDR and DRT HDR part, which contain the SDR and HDR colorspace conversions

DRT look control#

This advanced mode of controlling an ALF4c look allows you to send your whole look (including input and output transforms) as 3D LUT to the camera.

You can use this way of controlling your look to

• send a custom look containing the whole pipeline (e.g. ACES or CDL Advanced) to the camera. The look will be saved as an ALF4c file in the camera.

The entire look (including input and output transforms) of a slot will then be stored in the DRT part of the look, while CDL & Saturation, and CMT will be set to neutral.

Due to the structure of ALF4 files which consist of two DRTs, the 3D LUT is sent as DRT SDR or DRT HDR, depending on the output colorspace setting which was set in the camera device. The other DRT which won’t be used will be set to neutral.

Output Colorspace#

As the DRTs are responsible for the colorspace conversion, the target colorspace must be set when adding the camera in *DRT *mode accordingly to the output transform of the look you are going to send to the camera.

Example:

• If you set up an ACES look where you use an Rec.709 ODT, choose Rec.709 (SDR) as the output colorspace.

Adding a camera using ALF4 looks in DRT look control#

After adding a camera with look control set to DRT, Livegrade will

• set CDL & Saturation and CMT of the currently loaded in-camera look to neutral
• set DRT HDR or DRT SDR of the currently loaded in-camera look to the current look of the slot as 3D LUT, depending on the chosen output colorspace. The other DRT will be set to neutral.
• set DRT HDR or DRT SDR target colorspace of the ALF4c file according to the output colorspace chosen in the Add ARRI camera dialog.
• load the current look’s name from the camera into your Livegrade look’s name
• indicate a proper connection with a green light
  • If the connection process was not successful, please check your network and reconnect to the camera by removing the device from the slot and adding it again.

As soon as you successfully have added the ARRI camera in DRT mode to one of your slots, you can start live-grading.

Grading a camera using ALF4 looks in DRT look control#

Let’s take a look at what actually happens when grading an attached camera in DRT only mode remotely:

• All CDL, Saturation, Curves, LUTs, Input, and Output Transform nodes of your look will be merged into one single 3D LUT which will be sent as DRT HDR and DRT SDR to the camera.
• CDL and CMT of the currently loaded in-camera look will be left untouched during grading, as they were already set to neutral when adding the camera to the slot.

Grading an ALF4 look in DRT mode

The described behaviour works in all grading modes.

You will find an ARRI ALFc DRT Only look template for grading ARRI ALF4c looks in DRT look control mode in the CDL and ACES grading modes.

Look templates for CDL Advanced

Look template “ARRI ALF4c DRT Only”

Extracting the look from a clip that was recorded by an Alexa 35 camera will then give you

• an ASC-CDL containing a neutral CDL
• an identity 3D LUT representing the neutral CMT part
• two 3D LUTs representing the DRT HDR and DRT SDR part. The DRT which was graded in Livegrade, will contain the look created in Livegrade. The other one will contain a neutral LUT.

ARRI Cameras and Livegrade#

The following table summarizes the different camera types and possibilities to grade them with Livegrade.

Updating Looks in ARRI Cameras#

While there are differences in how the look can be graded in a certain camera model, the way looks are updated in the camera is the same for all ARRI cameras:

• A change of the camera’s look is indicated by a * next to the look’s name in the camera.
• When the camera records a clip, your look will be saved in the clip’s file header. This makes it possible that everyone who has the original camera footage or a copy of it can extract and apply your look during post production.
• To save a look permanently on the attached camera with the current look name, use the action “Permanently Store Look on Device” which can be triggered
  • via the main menu: Slots > [Permanently Store Look on Device]

Frame grabs#

In case you want to receive a frame grab from the camera in Livegrade, set the camera’s frame grab as image source in your slot.

If you want to get a constantly updated frame grab from the camera

• enable the “Continuously refresh frame grab” option.

To manually retrieve a frame grab from the camera, use the “Refresh Frame Grab” actions which can be triggered

• via the main menu Slots > [Refresh Frame Grab of Current Device]

Use camera’s frame grab as image source