Camcorder interfaces, such as Miranda’s DVC-800, provide extra functionality in on-set monitoring and editing.
The production world is experiencing a shift from shooting on film to electronic acquisition with HD camcorders. While shooting in HD won't always replace film, which has its own special look and gamma (qualities), it has penetrated a significant portion of the market for several fundamental reasons.
One reason is the wide acceptance of the 24p HD format as a universal mastering format. From the 24p HD format, which does offer many of the visual benefits of film, material can be converted to virtually any HD or SD format for broadcasting, archiving, DVD mastering and numerous similar applications.
What's more, the storage requirements of 24p HD content fall within a range that has become manageable with contemporary networking and storage equipment. In addition, new camcorders and interfaces can accommodate a complete range of other HD formats — including 1080i, 1080p and 720p — at all the popular frame rates, including 23.98PsF, 24PsF, 25PsF, 29.97PsF, 50i and 59.94i.
Pricing and availability have brought HD products into the mainstream, but the success of these systems rests also on the flexibility and efficiency they introduce into the production. They can give everyone on set — the director of photography, cinematographer, director, producer and now often the colorist — the ability to monitor images as they are recorded. On-set HD monitoring allows directors and producers to see shots as they are being taken, and then move immediately to scene selection and the rough-cut editing process.
Camcorder interfaces
HD acquisition can cut production time by nearly half. Rather than wait on film processing and a transfer of dailies, the production team can jump right to offline editing, scene selection and even preliminary color correction. As a result, the online editing process can begin as early as the next day.
HD production can become even more efficient with the use of electronic acquisition interfaces that mount on the back of an HD camera between the camera and battery.
These interfaces for HD camcorders typically feature multiple outputs including HD SDI, SDI, composite and DV/IEEE 1394, the last of which allows the camcorder to be plugged directly into a laptop/DV editing system or a DV portable drive. The DV signal includes embedded audio, time code and metadata, facilitating fast and accurate editing.
Typical configuration
These new interfaces may include built-in aspect ratio converters that allow 16:9 material to be viewed on either a 16:9 or 4:3 monitor, as well as time code burn-in (both video and audio), graticule markers and on-screen display of metadata information such as scene, take and reel number. These features allow everyone on-set to see the complete picture at all times. The inclusion of key scene information minimizes the possibility of expensive errors. If the HD interface provides a DV loopback feature, DV material can be recorded on a DV recorder (or a laptop) and later played back for review and approval on the set.
In a typical acquisition configuration, the HD camcorder operates in a self-contained manner. However, all of the preferable support and monitoring equipment still need individualized feeds to perform their duties. They can be developed from the HD feed from the camera. However, that requires a lot of extra gear.
It used to take a truckload of equipment just to get feeds from the camera for both HD and SD monitors so the producer/director and maybe the AD could “see” the images coming from the camera. The HD output from the camera couldn't drive the SDI monitor. These were significant obstacles to the videomaker needing HD quality and finding a complete solution unavailable. Add to this the drive to reduce staff and make the field crews smaller, and it's almost a wonder that HD field production worked at all.
Early attempts used an external downconverter to get an SDI image that could be used to drive an SD monitor so the director and other crew members could “see” what the camera operator was seeing. That was the first step. The problem remained that it didn't provide the HD quality that was needed. Cameras have an HD output, so now it was possible to add a second connection to the camera for an HD monitor.
Now we had both HD and SD, 4:3 and 16:9 monitoring, but what about time code? What about safe area markers? If we had a DV recording, the crew could do rough cuts in the field, putting them maybe 50 percent ahead in production time.
Figure 1. The support and monitoring equipment videomakers need when acquiring video need individual feeds from the camera. New conversion systems are now available that mount on the camera and provide these feeds. Click here to see an enlarged diagram.
All these factors necessitate the use of an on-camera downconverter. Shown in Figure 1 is an example connection diagram of a Miranda DVC-800 downconverter. This device mounts on the camera, just before the battery pack. It provides both HD and SD monitor outputs and DV/1394 to feed a DV recorder. It can capture metadata and audio, all while burning in time code if necessary.
Even effects-based shots such as blue-screen can be checked without waiting for dailies to return — and the inherent loss of an entire day of production. If the editing system has the foreground and background for the scene, an editor can simulate the final look of the scene while still on the set.
Such an interface can make remote shooting not only easier, but highly productive. These crews can become practically self-contained. They return to the studio knowing that the takes were good, the rough cuts are done and that conversion between 4:3 and 16:9 will not lose critical image information — because they've already seen the results.
As the new performance capabilities of HD cameras increase, video becomes an even more tempting solution over film than before. Armed with a few tools like this, the transition from film to video becomes easier — and even perhaps less expensive.
Gilbert Besnard is director of product development for Miranda.
