RED Digital Cinema is a start-up camera company that’s been greeted with skepticism since its launch. From its initial promise to revolutionize motion picture production with a 4K digital camera, RED has evolved a product line that currently includes the original RED ONE, EPIC and the soon-to-ship SCARLET. (The company announced SCARLET-X at a high-profile event on Nov. 3.)
REDCINE-X PRO supports a dual-monitor layout, so you can
show the full-screen viewer image on a secondary display.
Each of these cameras comes in various configurations and in time will offer increasingly advanced sensor technology. At the moment, the two actively shipping products—the original RED ONE and the EPIC—sport the same 5120 x 2700 pixel, Super 35mm-sized Mysterium-X CMOS sensor. In the RED ONE, this yields a frame size of up to 4480 x 2304 pixels, and 5120 x 2700 pixels in the EPIC. The cameras can record at various speeds, including higher frames rates for in-camera slow motion; however, at the higher rates, only a cropped portion of the sensor is used.
Bayer Pattern Camera RAW Motion Imaging
The RED sensors are CMOS chips that use a Bayer pattern design (named after Bryce E. Bayer, a Kodak scientist who developed this scheme). Light is filtered according to red, blue and green wavelengths, and each light-receiving pixel (photosite) records data for one of these three ranges. As such, a monochrome linear signal is recorded in which the photosite pattern corresponds to 50 percent green data and 25 percent each for blue and red data. This camera raw process is similar to that used by most high-end digital still photo cameras. The innovation that RED brought to the table (aside from deploying raw in a video camera) was to apply their wavelet-based REDCODE codec to compress the huge signal (4K frames at 24 fps) onto viable portable recording media (CF cards and hard drives).
These innovations added new postproduction steps. Native RED media (the .r3d format) cannot be viewed as normal video. Like any camera raw digital still, the data must be “developed” into an RGB color image, which involves properly reconstructing color information from the pattern of green and surrounding blue/red pixel information and applying exposure index, color temperature and tint values. This step can be a valuable creative tool because you have a lot of freedom to completely change the image from how it may have looked on monitors during principal photography. How well the Bayer-pattern information is “de-Bayered” is an important technical step, as it affects resolution and color accuracy.
Color Science Evolves
Over time, RED has refined its color science. In fact, it’s possible to convert older .r3d files with updated software and get an even better image out of them today than was possible at the time they were first recorded. That’s because improvements have been made on both the encoding and the decoding sides of the process.
Anyone working with RED footage needs to become familiar and comfortable with the postproduction tools available to them. RED makes an SDK (software development kit) available to developers that opens hooks for them into RED’s proprietary format. The SDK is updated based on camera firmware and color science changes; therefore, a newer SDK is required to accommodate the EPIC camera files. Software vendors who integrate the SDK into their application make it possible to access the native .r3d files and give the user control over native color settings as well as de-Bayer resolutions.
RED Media and Editors
Most desktop editing, compositing and color grading applications now offer some level of native RED support via the RED SDK. You can deal with any of the RED ONE files, but not all yet support EPIC files. The list includes Adobe, Avid, Assimilate, Blackmagic Design/DaVinci, Apple Color, Sony Vegas, Quantel, Autodesk and FilmLight, to name a few. Unfortunately, transcoding and de-Bayering a 4K compressed file is very computationally-intensive and even a fast machine will grind to a crawl if you want full quality.
Typically a software-only transcode at full de-Bayer quality can range from 6x to 24x slower than real time. The speed is mitigated through hardware. The best option, if you work with a lot of RED footage, is to purchase RED Digital Cinema’s RED ROCKET accelerator card. This is a PCIe card that handles the de-Bayer function, and many applications, such as Media Composer and Color, can access it to offload that part of the process during rendering. Other manufacturers, including Assimilate, Adobe and Blackmagic Design, have worked to leverage GPU power (particularly NVIDIA’s CUDA technology) to apply hardware acceleration to scaling.
This scenario changes if you are using the RED files only for offline editing and intend to do the finishing on another system. It’s possible to do a software transcode in close to real time on a fast machine by changing your de-Bayer settings to 1/4, 1/8 or 1/16 resolution. These are of adequate quality for creative editing decisions.
Tools for RED
In addition to the implementation of the SDK, there are a few standalone tools designed to work specifically with RED media. These have also evolved over time as the camera firmware has changed. Some have been the work of enterprising and committed RED owners, some of software developers, and some by RED itself.
Unfortunately for the developers, RED has been making its own tools available for free to anyone who wants to download them from its web site. Many of these tools have lacked ongoing support or have simply been dropped, since the financial incentive for serious development is missing for any developer other than RED. Some of the earlier tools included Crimson, Clipfinder, Rubber Monkey Extract and RED’s own RED Alert!, Redline and REDCINE. A few of these tools are still maintained by their developers, but many are not up to date with the most recent camera software.
The Foundry was on the path to developing Storm, a software application targeted first toward RED and eventually other cameras, like ARRI ALEXA. Due to RED’s continued investment in advancing its own tools, The Foundry decided to end-of-life Storm and has opted instead to incorporate part of that development into its new HIERO visual effects product.
If you work with RED files, then the best tools to use today are RED’s REDCINE-X or REDCINE-X PRO. Each of these applications is a full-blown file correction, rendering and management tool focused exclusively on .r3d files. They work alone or in conjunction with a RED ROCKET card for accelerated playback, rendering and output to a video monitor. As with most RED products, each of these software tools is in a continuous beta mode, so always check for updates. For now, these two tools are very similar, but it looks like REDCINE-X PRO will add stereo 3D controls and the ability to add plug-ins. Either REDCINE-X or REDCINE-X PRO is fine for most RED projects today.
The biggest use of REDCINE-X for most editors is to convert files into an edit-friendly format, like Apple ProRes QuickTime files. In some cases, you’ll do one conversion and never touch the .r3d files again. The starting point is to load a folder of .r3d files from a card or hard drive copy and make any necessary color adjustments. In addition to control over the native camera raw settings, REDCINE-X includes a full set of primary color grading tools, like lift/gamma/gain color wheels and curves. You also have control over image cropping and scaling for export. Color adjustment changes can be stored as metadata in a separate .rmd file (accessible by some applications to apply a look to the .r3d file without rendering), or you can simply render and export files with the new correction “baked in.”
A second way to use REDCINE-X is for offline-online workflows. It will import EDL and FCP XML lists that can be relinked to the original .r3d files. These are displayed along a conformed timeline. In this approach, REDCINE-X can be used for complete, in-context primary color grading, much like Color, Resolve or similar tools. When finished, you can batch-export individual clips from the bins or the complete timeline as a single piece of rendered media. If a RED ROCKET card is installed, the time to render 4K files to 1920 x 1080 (with full-resolution de-Bayering) is approximately real time. The usual offline-online approach would be to render all clips at low resolution for editing. When the cut is locked, send a list to REDCINE-X and re-render the selected clips at higher quality. Then in your NLE, simply relink the sequence to the higher-resolution media for finishing.