Setting Up After Effects for Transcoding (recommended method)
This brief guide is for transcoding a single raw DNG image sequence to Cinelog-C colorspace in a DNxHD Quicktime video container. There are many methods for transcoding footage for single and multiple clips to various codecs and image formats using After Effects, Premier and/or Adobe Media Encoder. We will be posting additional guides/articles looking at other transcoding and codec options plus editing and round-trip color grading in other apps.
This guide may at first seem complicated and lengthy, however many of these steps can be saved as reusable presets or templates. We feel it is important that you familiarize yourself with the following basic procedure to gain a better understanding of how it works before saving After Effects project settings, Output module render settings and Adobe Camera Raw defaults as reusable presets.
In After Effects
Open After Effects and create a new composition with your desired frame rate and size (i.e. 24fps/1920x1080)
Open the Project Settings panel and set Depth to 32 bits per channel (float). Working Space should be set to HDTV (Rec.709). Compensate for Scene-referred profiles should be ticked. Linearize Workspace, Blend colors using 1.0 gamma and Match legacy After Effects QuickTime Gamma Adjustment should be unticked (no tick). Other settings can remain at their defaults.
Click on OK.
In the main After Effects menu - Click File>Import>File and locate the folder containing your DNG images
Tick the Camera Raw Sequence box and double click on the first DNG. This will open the first DNG in Adobe Camera Raw.
In Adobe Camera Raw
Select the Camera Calibration tab (camera icon) and choose the Cinelog V3.0 camera profile for your camera.
If you cannot load the Cinelog V3.0 profile for your camera :
The UniqueCameraModel DNG tag is used to identify a camera for Adobe Camera Raw to load compatible profiles. Occasionally, camera manufacturers (i.e. indieCAM) change these tags (and occasionally matrices) as part of a major firmware update. As a result, ACR will not show the Cinelog 3.0 profile. We make every effort to keep model tags up to date, but if you do not see the Cinelog V3.0 profile for your camera (i.e. ACR may only show 'embedded' as an option) simply send us a single DNG where the profile is unavailable. We will re-tag the profile, send you a new one and add to our profile pack as quickly as possible. Please keep older revisions in the profiles folder as they will be needed for your older footage.
Contd ... Check each of the main tabs (including all sub-tabs contained within main certain tabs) and ensure that all settings are set to zero (0) or default values and that no curves have been added. Tip: Once you have checked everything you can save this as a new Camera Raw default.
White Balance can be adjusted if needed. Auto White Balance can be used but we strongly suggest manually re-typing the color temperature and tint adjustments (so that the white balance reads as Custom) this avoids any dynamic white balance shifts from image to image.
Sharpening and Noise reduction can safely be used. Tip: Hold the CTRL key when adjusting sharpening controls to see masking and detail.
Exposure Adjustment - Cinelog V3.0 Camera Profiles have a preset exposure offset (camera specific) to ensure normally exposed images are fully within the upper and lower bounds of the histogram. For the majority of correctly exposed images, no further adjustment is necessary. The Clipping indicators (triangles on the upper left and right of the histogram) should however be enabled. In the unlikely event of image showing clipping (red or blue solid color showing on the image itself in highlights and shadow areas) a small degree of Exposure adjustment can be made using the Exposure Slider. It is important to adjust as little as possible at this stage and just enough that the image no longer shows clipping.
Click OK to import the image sequence into After Effects
Back in After Effects
Your image sequence will now appear in the Project panel but is not yet on the timeline. First we need to tell After Effects the correct frame rate.
Right+click on the footage in the Project Panel
Select Interpret Footage>Main
Enter the frame rate at which the footage was shot (if different from the project frame rate) and select Pixel Aspect Ratio - Square Pixels (unless footage was shot with an Anamorphic lens, in which case set this to match the lens stretch ratio)
(tip: clicking the More options button will reopen Adobe Camera Raw if you need to make further adjustments to Exposure, white balance, sharpening or noise reduction)
Drag your footage to the composition timeline, adjust scaling/framing if needed. The image will appear very flat - this is correct.
Add the OpenColorIO plugin (found in Effects>utility)
The Cinelog-C OpenColorIO configuration has many full colorspace input/output options (using CIE XYZ as the connection space). Other default (gamma only) configurations are also included for VFX and Animation.
The Cinelog-C configuration can also used as a bridge to ACES 1.0 OCIO by selecting Output Space as ACES and Input Space as ACES 2065-1 in the ACES 1.0 config (not included).
To check exposure levels are ok before rendering you can use OCIO plugin with the following settings:
Input Space - Cinelog v3.0
Output Space - Cinelog-C Rec709
Note: Cinelog v3.0 is always used as the Input Space used when transforming raw images from ACR
If you feel the exposure needs adjusting further you can either go back into Adobe Camera Raw and use the exposure slider (recommended method) or add the After Effects Exposure plugin BEFORE the OCIO plugin and adjust +/- until the image looks correctly weighted. Do not use the exposure offset or gamma controls and leave bypass linear light unticked.
Cinelog V3.0 has performed the Linear to Log conversion but the colorspace (RGB primaries) require a further transformation to Cinelog-C wide Gamut RGB to ensure no pixel values are clipped outside of the 0.0 - 1.0 range when the image is rendered using a 10bit codec. This also makes the image compatible with Cinelog Look Luts.
To transform the colorspace simply change the Output Space to Cinelog-C
We are now ready to render a log master in ProRes or DNxHD - other codec options are available in After Effects but we suggest either ProRes HQ or DNxHD minimum of 4:2:2 but preferably 4:4:4 for the best color preservation.
Render a Cinelog-C Log Master or Add a Look
We recommend rendering a log master (as described below) as it is a more efficient format for working with but alternatively, you may choose to render from raw to deliverable format by adding a Cinelog-C Film Look lut. The OCIO settings will be as above to ensure the image is in the correct colorspace. You can then either use the native Apply Lut plugin in After Effects or better still, use another instance of the OCIO plug and take advantage of it's superior tetrahedral interpolation.
To load a look lut into the OCIO plugin simply add another instance of the plugin, select Custom from the configuration dropdown menu. Find and select the lut you wish to apply and click OK. Then set Interpolation to Tetrahedral.
Rendering a Cinelog-C log master in After Effects
In this example we will render to Avid DNxHD 4:4:4 but other options will be available depending on your platform (i.e. ProRes on OSX). Always choose a 10bit or 12bit codec option when creating a log master (intermediate) - never use H.264 or other 8bit codecs as these are delivery codecs.
In the main menu select Composition>Add to render queue
In the Render Queue select Output Module to open the Output module settings dialogue
Select format: Quicktime, tick the Video Output box. Channels should be set to RGB, Depth - Millions of Colors.
Click the Format Options button and select Avid DNxHD Codec with quality slider set to 100
tip: these settings can be saved as a render preset
Select your output location and name your video and click the Render button to render your log master!
You will now have a QuickTime DNxHD video file in Cinelog-C colorspace to work with in any editor you choose. if you wish to edit in After Effects or Premier simply import the new QuickTime video file then Right+click and choose interpret footage. In the Color Management panel tick the Preserve RGB box.
The video file you just created is also now compatible with Cinelog-C REC709 and Film Look Luts. It can also be transformed accurately to other log colorspaces if required (not usually necessary but useful for using luts intended for other colorspaces/cameras) or graded using curves and color wheels. To transform to REC709 simply add an instance of the OCIO plugin and select Cinelog-C as the Input Space with Cinelog-C Rec709 (or any of the Cinelog-C REC709 options) as the Output Space.