Multimedia
Blogs
Forum
Affordable HD
Whitepapers
Newsletters
Events
Advertisers
DCP Directory
MillimeterShooting for DVD: Reviewing the Fundamentals
Feb 9, 2006 11:40 AM, Barry Braverman
In this first installment of a two-part series, DP Barry Braverman outlines the basics for shooting with DVD output in mind. Be sure to read the February 9th issue of DVD Focus for the conclusion to Shooting for DVD.
DVD is big business. In 2004, retail sales of DVD product exceeded $25 billion, which begs the question as a pro-level shooter of film and video if you’re doing enough to wrest the best possible quality images out of the five-inch discs.
Because DVD-Video entails significant compromises with respect to compression and related motion estimation issues, it makes eminent sense that we adjust our thinking at every stage of the imaging process to better accommodate the format’s requirements and idiosyncrasies. It's not just matter of addressing DVD’s high compression either.
Many of us already understand that MPEG-2 is a perennial problem child whose complexity and shortcomings make artifact-free pictures a major challenge especially at low and moderate bit rates. There may be abundant reasons for less than stellar video on DVD, but one thing is for certain: Compressing your images to DVD-compliant MPEG-2 is a horrible thing to do.
CAPTURING THE ESSENCE
Of course this is the business we chose so compression to MPEG-2, however arduous, comes with the territory. We can begin to address this challenge in-camera by following a modus operandi optimized for the DVD-centric workflow. New motion picture stocks like Fujifilm’s ETERNA 500 now feature extremely fine grain, the tighter image structure helping to reduce artifact-inducing noise in the MPEG encoder.
Noise is public enemy number one when it comes to producing clean images on DVD, so reducing it from all sources is critical, beginning with original image capture. Fujifilm’s super-nano ultra-fine grain certainly helps in this regard but so does utilizing proper on-camera filtration, a light Tiffen Black Pro-Mist or Schneider Black Frost serving to tighten the image structure substantially and reducing high-frequency artifacts in detailed scenes such as landscapes.
Keep in mind the challenge that film shooters face in this mad digital world: the film look and associated grain can enhance the visual storytelling or work against it by contributing to a maelstrom of ugly artifacts. This is where your craft enters the picture. The right film stock, exposure, camera filter, noise reduction strategy and encoder settings, all of these should help further the visual storytelling experience. Film grain in itself is neither a villain nor a hero in this context, but simply another tool for the shooter to control and exploit (hopefully) in a positive fashion.
Color gradation and gray scale has also been improved in modern motion picture films resulting in better overall balance and skin tones. This in turn reduces the risk during scanning or telecine of color anomalies, such as objectionable red hue shifts in deeper facial shadows. More accurate capture of flesh tones in the original negative can go a long way to mitigate such color shifts later in the digital workflow, these artifacts tending to be greatly amplified due to the high compression applied in the MPEG encoder.
The wider latitude and improved color couplers between the emulsion layers in today’s film stocks also results in greater sharpness, thereby reducing the amount of electronic enhancement required in the telecine or scanning operations. Minimizing the artificial “detail” added in these environments will produce more natural and professional looking images at the end of the rainbow, as the plastic edging around objects is minimized and therefore less likely to appear to cause trouble at various stages up to and including the preparation of the DVD.
COMMON RECOMMENDATIONS FOR FILM OR TAPE
Whether originating on film or video, the shooter can take advantage of common strategies in order to achieve the highest quality possible DVD images. Appropriate on-camera filtration is critical as proper contrast control helps preserve detail that would otherwise be clipped or eliminated in the blown-out highlights. Remember that detail not captured in the first place cannot be restored later regardless of the sophistication of one’s postproduction software, so video shooters especially need to be cognizant of the clipping threat. Film shooters of course enjoy a bit more piece of mind in this regard owing to the medium’s superior dynamic range and concomitant better ability to rein in detail at both ends of the characteristic curve.
Considering the best frame rate for DVD release, shooting 24 fps is logical and smart since every DVD player is in truth a native 24p device. Keep in mind that 24p video actually runs at 23. 976 fps so film shooters not intending a film-out for theatrical exhibition may want to adjust their film camera tachometers accordingly to avoid potential synchronization issues down the line.
Major movie studios and entertainment companies have originated on 24 fps film for decades and so logically they continue to encode their movies at 24 fps for DVD. Relying on the player to perform the required telecine conversion to 29.97 fps, the DVD shooter-producer can capture, edit and encode an entire production at 24p, thus averting onerous NTSC artifacts while also reducing the size of the finished encoded program by 20%. This is not an insignificant amount in an era when producers are routinely jamming everything and the kitchen sink on their DVD releases.
Shooting 24p also improves resolution and image fineness by eliminating the 1/60th second temporal artifacts that can occur between fields; the suppression of these combing defects being a major factor in improving the look of DVD encoded programs produced at 24p.
Shooting 24p does carry with it some peril as strobing defects may become more apparent after compression to DVD’s long-GOP MPEG-2. This strobing danger, often seen in spinning stagecoach wheels for example, is exacerbated when panning or shooting moving objects at certain angles. This picket fence is the classic 24p ambush: the tracking camera at a right angle will typically produce a nightmare of strobing artifacts that may not be obvious until played back from the encoded MPEG-2 file.
--To Be Continued…
