What Canning impressed upon Bagdonas was that his lighting skills were essential to successfully working with HD video, but that there was no need to guess about the outcome. Shooting with video did necessitate some changes in production procedure, however. Canning explains, "In film, they block, light and shoot. With video, we block and light, but then let the video shader look at the image and make the necessary adjustments. Think of it like this: we're doing exposure, color correction and workprinting in real time. It doesn't happen later at a lab."
Most importantly, Canning recounts, "We wanted to make sure that the Chicago Hope crew had a very good experience with the camera, had no down time, and shot no slower than they would normally. But we needed to know what they were going for, and then have the time to achieve it the video way."
For example, the HDC-750 can be set to create a shallow depth of field by running at -3dB gain and, if necessary, adding a neutral-density filter. This allows the iris to be opened wider and brings the user closer to the kind of focus control that's found in the film realm. Of course, this type of solution is not what film people are accustomed to doing, and the results are not quite the same as with film cameras. "We're used to using long lenses to give us a shallow depth of field," says Bagdonas. "We opened up the stop a bit, but even then we couldn't truly get the separation that our 35mm film camera lenses give us."
So what did they do when the director wanted to rack focus? "We were still able to do it, but it wasn't what we were used to," Bagdonas says. "We had to keep the frame size the same, so we needed to go longer on the lens, and sometimes you just don't have the room to back up and do that." This may be a set-design lesson for the future.
Another example of how film and video solutions differ arose during the shooting of close-ups of female performers. After seeing the regular camera crew automatically drop in a diffusion filter for these shots, Canning broached the video solution: use the "detail" or "enhancement" adjustment to add or subtract sharpness in the picture, thereby eliminating the need for lens filtration. The HD-750 camcorder also has a feature called "skin detail," which allows for the automatic removal of detail information just in the skin areas of the picture.
What needs to be overcome, Canning believes, is the tendency to use the video camera exactly like a film camera. "You can't do it," he emphasizes. "In film, you're looking for exposure and focus, and you use different film stocks for different light levels and expose within the correct range. Video has a fixed dynamic range. Film people like things dark; they want to expose at only 30 percent of video level. But if you're only making 30 units of video for your brightest scene, then flesh tones are down at 15 percent, and you've wasted the full dynamic range of the camera. If you get into post and decide you want it brighter, they can do it, but you're going to pull up the noise level."
Looking at the HD and NTSC monitors on the set — situated about 25' from the camera — the producers and cinematographer thought the high-def image was crisp and detailed. Bagdonas remarks, "It was jarring, as if we were watching the scenes through a window. However, because of the level of detail that was being recorded, we were concerned because our sets were designed for film." To elaborate, the cameraman explains that while film translates textures and colors to render a particular cinematic tone, video records them differently and the resulting images take on a "live and happening" feel. Because of this, the sets took on a different character.
It didn't take long for Bagdonas and the Chicago Hope crew to recognize this perceptual difference and figure out which procedural adjustments they needed to make. "We lit things as we would for film," says the cinematographer, "while still being aware that the [lighting and] contrast ratios were a bit lower. Working on film, if I had light coming through a window, a hot background, or hotter highlights, I'd let them be three or four stops hot. With video, I wouldn't let them go more than two stops to get the same result, to avoid blooming or bleeding out the whites."
The cinematographer adds that he quickly realized that he also had to be very careful about detail in shadow areas: "With film, you know that shadow detail will fall off and blend in. In HD, you can see it all. Because of the low lighting ratio, we had to work harder to retain the blacks in the shadows."
[ continued on page 3 ] © 1999 ASC