Desktop DI

It's time to start thinking about your future. For content producers, the biggest challenge today is finding the best price to performance ratio when creating production that might have a long shelf life — shooting SD today may reduce the value of your projects' royalties performance when HD television eventually is widespread. Future-proofing your material is just one aspect of the new project-finishing environment that began with digital intermediates.

Red Giant Software's Magic Bullet Suite is two tools in one: a de-interlace and artifact remover and a set of filters to create film looks.

Strictly speaking, digital intermediate is the step between camera negative and film projection ostensibly to reduce the inevitable degeneration that occurs during the several intermediate steps of duplication on the way to the cineplex. But the first digital intermediates were actually used to introduce art direction or “look development,” such as the black-and-white isolated color in Pleasantville or the bleached and subdued color for O Brother, Where Art Thou?

The mention of two big Hollywood movies may sound expensive, but the opportunities of DI are as available to low-budget filmmakers as they are to directors of Hollywood productions. Over the past 18 months, there have been many stories profiling facilities focusing and modifying the DI process for the indie film market, and with the recent introduction of enhanced HD capability in Apple Final Cut Pro, Adobe Premiere, and After Effects, DI on the desktop is a very real creative opportunity.

Color correction in 16-bit on the desktop has been around for a couple of years, so you might be wondering how DI on the desktop changes anything for small studios conforming to the standards of broadcast NTSC. The main difference is that desktop DI introduces the concepts of a universal master and future proofing.

The universal master is the Holy Grail in distribution and a fundamental consideration for any digital intermediate. There are many output options for a movie, including film, digital projection, NTSC, PAL, DVD (letterbox in several aspect ratios as well as 4:3), and various web formats. Of course, frame rate conversion will probably be necessary. The universal master is on every equipment manufacturer's mind, and no one has completely solved the challenge.

Let's say you have a cable series or corporate education project. Today you may have only one delivery format, but how much extra effort is required to future-proof your assets? HD is rapidly reaching the American public, and your project may have a longer shelf life if you can provide a native HD version later. There are even benefits to considering a universal master now if you expect to cannibalize footage later on. A universal master is not for everyone, but if you are working in HD already, the extra steps to prepare for later use in different formats might make sense. Even today many programs must be available in multiple formats. Until recently, most production companies simply downconverted or upconverted their finished programs without optimizing the workflow.

Digital intermediates fall into two categories: data based (RGB) and video based (YUV). Data means working from TIFF, TARGA, Cineon, or EXR files in resolutions from 2K to 6K. Typically, data is recorded at 10-bit log (internally, the calculations are 16-bit or higher). All the above requirements exist to preserve the integrity of a project recorded on film. Systems like Grass Valley's Spirit DataCine (the 4K version is YUV and RGB) and software grading systems such as Discreet's Lustre work with data.

The alternative is to work in YUV video space in HD file sizes (usually 1920×1080) at 8-bit color depth typically on a da Vinci or Pandora Pogle color correction system. This is considered tape-to-tape color correct, where the resolution and color space requirements for broadcast are less than film. Tape-to-tape color correct sourced from D5 or HDCAM in 4:2:2 (or 4:4:4 in the case of HDCAM SR) is an affordable digital intermediate solution that is being used by many indie filmmakers and even a few Hollywood films.

This is a simplified description of the complex DI issues for those working with a film acquisition. Desktop digital intermediates are usually projects that begin as HD or SD video.

There are various color profiles used in our industry. When creating a universal master, the choices are ITU-R BT .709 or ITU-R BT .601. BT .709 is essentially the ratified 1920x1080 HD sampling structure (analog and digital), while BT .601 is the digital 525 and 625 (NTSC and PAL) sampling structure commonly understood to mean color difference component digital video or 4:2:2. It can get a lot more complicated than this, but from the process point of view, it may make sense to create your universal master for HD and not SD broadcast.

Your SD versions for DVD, broadcast, etc. will be subsampled from the HD standard BT .709 color gamut. These can be stored in D5 or HDCAM. If you are color correcting for film, then you will save the data files corrected in 10-bit log on hard drives. When filmout is necessary you will downsample all additional formats from the 10-bit log version. Synthetic Aperture, the developers of Color Finesse color correction software, will be adding .709 markings to their virtual scopes in the next version, due out this year. For the record, .709 is quite close to .601, but this is the way the industry is moving, so get on board now. The trend to add BT .709 workflows to common NLEs will be coming over the next year.

A few things to remember if you are considering future proofing and color correcting your own projects:

• Shoot for the highest output medium, even if it requires more storage space.
• Shoot test cards (grayscale and color) for lighting situations. Use the CamAlign colorbar/grayscale charts from DSC Labs.
• Set up your monitor white level for D65 (6500K). Here's a good site with easy-to-understand setup instructions: www.ltlimagery.com/monitor_calibration.html.
• Include the DP and the editor in the decisions on camera setup and monitor gamma assumptions (usually 1.8 or 2.2). Test your digital pipeline from camera through output before shooting.

While good data management — and that's what a universal master addresses — makes for better pictures and less work, look development is what DI is really about.

Synthetic Aperture's Color Finesse is a standalone color correction tool with scopes and waveforms. It is bundled with After Effects 6.5.

For most of the century, photographers have been able to manipulate their images in the darkroom while making prints. Control over the gamma was accomplished through the selection of printing papers with different tonal characteristics or with Polycontrast paper and filters. Dodging and burning discreet areas of a photographic print allowed for a kind of painting of the image, as did retouching and airbrushing. Photoshop brought this image editing to still images, and After Effects, Combustion, and Bauhaus Software's Mirage bring this type of control to motion images.

We are in a transition period now as robust DI look development is possible on the desktop. With so many music video and commercial directors moving over to long form, the practice of finding the look of a project at the last minute in post is now common practice, which has helped push the interest in DI.

The best known “film look” product for Windows or Mac is Red Giant Software's Magic Bullet Suite, which comes in SD and HD versions. Magic Bullet made quite a splash when it appeared a few years ago, and as the name suggests, it filled a niche in the marketplace as DV narrative films exploded on the indie scene. It's really two tools in one: a de-interlace and artifact remover and a set of filters to create popular film and color correction styles. This includes things like bleach bypass and popular looks like the green-techno tint that are common in commercials and motion pictures.

When they first came out, Magic Bullet had superior de-interlace tools, and while still excellent, competitors have upgraded their algorithms. The pre-set color correction looks can be created in Final Cut Pro, Premiere Pro, After Effects, and Combustion with a little know-how, but if you don't know the tricks, Magic Bullet is worth every penny. Not just because it delivers lots of color correction styles at an affordable price, but because it provides a well-defined finishing path. The tutorials and documentation are instructive and clear. If you plan to use Magic Bullet, expect to use extra drive space and multiple workstations to accomodate big files and long renders.

Another Red Giant tool is eLin, which is not a tool for the fainthearted. It certainly helps to understand color space to use eLin since it takes over your HD workflow in After Effects, but investing a few hours in the principles and logic behind it will only help you become a better colorist. The idea behind eLin is that it creates a color space for your comps that is far wider than you would normally have by “cheating floating-point performance” (to quote the documentation). ELin can represent whiter than white in images by redistributing After Effects 16-bit color space to emulate the range found in high dynamic range images (HDRI). The immediate benefits are to motion blur and other transparency effects when composited over other images.

The main importance of this tool for digital intermediates is that it allows you to manage color according to lab calibration points and stops. This is a high-end tool and one that is not of value to everyone. Currently free for non-commercial use.

Digital Film Tools (DFT) is the software wing of Digital FilmWorks, an L.A.-based visual effects facility. They make four sets of filters: 55mm, Digital Film Lab, Composite Suite, and zMatte. The sets are available for After Effects, Photoshop, Avid, and Final Cut Pro. The first two, 55mm and Digital Film Lab, are of particular value for “look development.” DFT has staked out the photographic approach to digital features by emulating optical and film processing looks. As with many filter plug-in sets today, DFT filters such as Black Mist, Black & White, Color Grad, and Diffusion can be created using the adjustment tools found in the host software. However, you can get there much more quickly with these presets.

The filters are all adjustable and quickly add optical filter effects that are familiar to most photographers, however, every now and then a filter is provided with either a really smart interface or surprising algorithms. Light and Ozone are two of the most useful filters. Light allows you to add — by means of a black-and-white image — a lit area behind a foreground element.

Far more versatile is Ozone, a selection tool based on the luminance of an image and calibrated to Ansel Adams and Minor White's Zone System. This allows you to create the classic 10 zones in an image, thereby easily isolating elements to which you can apply color of other adjustments. Intuitive and quick, it lets you rapidly step through sections of your image that more often than not are the areas you want to treat selectively.

Fnord Software has created two inexpensive color management tools — Power Picker and Übercolor — for After Effects that are all but essential once you've used them. Both are ideal for color correction work. Power Picker pops up as an effect and stays open while you make changes — they appear instantly. Power Picker also has a color-mapping mode that is great for applying tints in realtime.

Übercolor is a color-mapping filter that allows you to easily make color space conversions to your footage. When the Übercolor filter window opens, you have Source parameters and Destination parameters. NTSC or PAL broadcast color space can be converted to Apple RGB with a few mouse clicks. You can also export files in the same way and convert in the opposite direction. However, color space conversion of this type may involve rounding errors and other degenerations.

Desktop digital intermediates really mean the discipline and practice of post finishing with digital tools based on a universal master, and with realtime or predominantly realtime color correction and look development.

Final Cut Pro, Premiere Pro, Avid Xpress DV, After Effects, and Combustion all have excellent 16-bit primary and secondary color correction tools. With the availability of additional filters for enhancing the look of footage widely available for most NLEs, the need to take your footage into a more powerful effects environment like AE for look development is not as important as it was a few years ago.

Processing in 16-bit requires more rendering time and storage space for files and is largely a requirement for film projects. For broadcast, all programs eventually end up in NTSC color space in an 8-bit format. While the added precision of 16-bit processing reduces some instances of banding, whether or not it's required depends on your footage.

Color correction tools are really meaningless unless the overall workflow is considered. This includes the color correction software, display system, I/O boards, and consideration of the output format. Desktop color correction for broadcast and HD are becoming straightforward. Excellent reference material can be found on these subjects in Color Correction for Digital Video by Steve Hullfish and Jaime Fowler. This book covers vector-scopes and waveforms in detail and tends to favor technical explanations.

A more practical approach is found in Color Correction for Final Cut Pro from Digital Film Tree. This is a very straightforward how-to manual for FCP explaining in simple steps the use of color chips on-set, monitor calibration, scopes, and ending with color correction projects. They also have a manual explaining, in equally practical style, the use of FCP's Cinema Tools for managing a film project.

S.D. Katz is a New York-based writer/director and is currently at work on an independent feature.

To comment on this article, email the Video Systems editorial staff at vsfeedback@primediabusiness.com.