Most film and video professionals will probably never get the chance to work on an “A” level feature film, but the same electronic advances that are impacting mainstream feature film post-production are making it easier for low-to-medium budget filmmakers to create personal, innovative stories with a more polished look than ever before. It is no longer a forgone conclusion that a low budget film has to look low budget. It doesn’t have to be shot in Hi8 or DV and recorded to film with tons of image degradation. Tools like affordable HD cameras and electronic post offer many new options.
The Traditional Approach
The workflow to finish a typical feature film has been something like this. The film is creatively edited using either a film editing system (like a KEM flatbed or an upright Moviola) or a nonlinear video editor (Avid, Lightworks, Final Cut Pro). In the first process, the editor physically cuts and splices workprint that was printed by a lab from the camera original negative film. The second process uses a videotape copy of the negative or the workprint, created during a film-to-tape transfer session. Once the creative editing is completed using either method and the picture is “locked”, a negative cutter goes back to the camera original negative and assembles the final cut of the film, based on a film cut list (like a video EDL) that was derived from the creative edit (film or NLE). Any optical effects, like titles, freeze frames and visual effects are composited by an optical house, special effects company or film lab and delivered to the negative cutter as a completed effect on film to be inserted into the final “conformed” negative.
This assembled negative is then “color timed” (color-corrected) and “answer prints” (review and approval copies), interpositives, internegatives and final release prints are generated. Of course, the audio editing and mixing has followed a parallel path and the mixed surround track is combined with the picture during the final print phase. As you can see, theater release prints are actually quite a few film generations away from the camera original negative and suffer some degradation in all of these steps.
Digital Intermediates
From about the time of “Terminator 2”, the film industry has proceeded down the path of increasing use of digital technology to replace traditional film methods. There are four reasons for this: a) increased use of electronic visual effects, b) preserving the negative in a digital data form, c) the application of video-style color-correction technology and d) improved quality through fewer film generations and less handling of the negative. A critical step in the digital intermediate process is to electronically scan the negative at 2K or higher resolution. The term 2K applies to scanning the full aperture 35mm film frame (4×3 aspect) at a resolution of 2048 x 1556 pixels (72dpi). This is considered half the resolution of the film. 4K (4096 x 3112) is considered full resolution. 2K is generally considered adequate for most mainstream use because of the inherent loss of resolution that happens during the traditional film steps by the time you see a release print in the theater.
Many of the 2K post processes are real-time or near real-time, whereas 4K is much more expensive and slower due the drastically higher data rates. Most films use the 1.85:1 aspect ratio, so the top and bottom of a full aperture 35mm film frame is cropped, which results in less than 1556 or 3112 pixels worth of vertical data in the final prints. Although a 1.85:1 film frame at 2K resolution is fairly close to HD’s 1920 x 1080, the scanned film frame still has a lot more information because the data is captured as a 10-bit file in full RGB color space. By comparison, Sony’s CineAlta 24P HDCAM camcorders are highly compressed and use the (reduced color information) YUV color space. The comparative file sizes for a single frame are 4MB of data for HD, 12MB for 2K of 35mm and 48MB for 4K.
Up until now, film scanning has generally been done from a cut negative or an assembly of selected shots with handles, which still involves a fair amount of handling of the negative. Many digital intermediate film labs are moving towards an electronic assembly from raw (uncut) camera original negative. In an approach similar to offline/online editing with an EDL, digital intermediate labs can now apply electronic cut lists to the scanned negative and produce a “conformed” negative that only lives in an electronic world, just like any other NLE timeline. These clips can be color-corrected and augmented with visual effects in much the same way as other video programs, but at full 2K (and eventually 4K) resolution in real-time. Products like Quantel’s iQ have started to pop up all over the world at labs and film production facilities that are serious about the move to a full digital film post-production environment. The “digital film master” is then “recorded” to a film negative (called the “film out” step), compressed to a digital theater presentation format (like Qubit or Windows Media 9) or downconverted to HDTV, PAL or NTSC.
Options for the Digital Filmmaker
So far in this discussion we have replaced an expensive film finishing process with a not-so-much-cheaper digital intermediate process. How does that help the bottom line for the shoestring budget? Part of the key is in 24P HD technology. The 1920 x 1080 24fps progressive video format (1080P) is considered a “universal master” or Common Image Format, because it can be readily converted to NTSC, PAL and also film. 1080P isn’t the same resolution as 35mm film, but it’s pretty darn close. Certainly films like “Star Wars, Ep. 1 and 2” and “Once Upon A Time In Mexico” are examples of the quality that can be achieved with proper control and attention to detail.
Sony’s CineAlta 24P camera packages are available for rental at comparable rates to 35mm film packages, but you don’t necessarily have to shoot CineAlta to get the benefits of HD. At the lowest price range, Panasonic’s AGDVX100A lets you shoot 24P 16×9 standard definition video. One of the beauties of progressive video is that it upconverts quite nicely, so if you run this recording through a Teranex converter, the result is some very good-looking 24P HD out the other end. You can improve the camera side by using Panasonic’s 900 (also standard definition) or the HD Varicam.
Or you could still choose to shoot on film. 16mm and Super16mm film have enjoyed extended life with HD. Properly exposed negative looks very good after a high-quality HD film-to-tape transfer. Shooting Super16mm, posting HD and then recording the final product to 35mm can yield superior results, more cost-effectively, than having a 35mm blow-up made from the Super16mm negative. Remember that conversions and transfers can be done relatively quickly, because no heavy-duty color-correction needs to be applied at this point. Final color-correction will be applied in post.
Once you have your camera original onto HD videotape, you can look at various editing options. There are over a dozen HD editing solutions, ranging from software and boards – added to a Mac or PC – up to full-blown, turnkey systems. Most will do the trick. You just have to figure out what fits your budget. An offline/online editing workflow is probably the best idea. For instance, Final Cut Pro 4.1 in conjunction with Automatic Duck provides a path into Quantel’s iQ. Use this formula to perform all the time-consuming creative editing at your leisure in Final Cut – then rent a few days of online time at an iQ facility to see your digital film master assembled in real-time!
If you decide to buy the HD gear, the investment is a fraction of the cost of a few years ago, since you can rent, rather than purchase, the HD VTR – now the single most expensive item in modern, low-cost NLE suites. A key to efficient post is real-time color-correction. This might require outsourcing if you’d like to use a daVinci 2K or Discreet Lustre color-grading (color-correction) system; or, it could mean going with a card like the Blackmagic Design DecklinkHD (in a G5), which promises real-time color-correction with HD video.
Once your program is edited, color-corrected and mixed, lay the final sequence to a 24P HD master and you can start shopping for the right distribution outlet. Standard def TV, HDTV, direct-to-DVD, digital theater projection or theatrical film prints – all are easy and not that costly when you start with a universal master. For more information, you may download Avid and Quantel white papers which I have posted to my website.
© 2004 Oliver Peters
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