Huh, I wondered about that. I'd always assumed most older U.K. shows were shot 25 FPS. Was it easier to shoot 24 then speed up the to PAL video?

The Blu-ray editions are transferred from a film-out source, not from the original camera recordings.

Therefore, 24 fps is the correct frame rate, regardless of what happened in-camera.

Generally speaking, a slowdown from 25 frames to 24 frames is much less noticeable than a speedup from 24 to 25. The production team may have also tried to compensate for it by pitching up the audio during mixing. If that happened, returning the frame rate to 25 fps would sound wrong.

UK HD television broadcasts are 50i, but the Blu-ray release may be returned to the original frame rate if it was shot at 24 fps

It was a mix. Anything shot on video would have been 50i. If shot on film, the production team had the option of 24 fps or 25 fps. 25 would be more directly compatible with PAL, but sometimes concerns about international syndication may have dictated shooting in 24 fps regardless.

European viewers are accustomed to PAL speedup and pitch shift due to having grown up watching content that way. It usually doesn't bother them as much as it bothers an American viewer. Likewise, European viewers may be much more sensitive to 60 Hz judder than Americans are.

"There was a lot of location work and a lot of building on location, and that's expensive in London. We knew that if we shot on 35mm stock in a conventional format, we would probably have to lose quite a few scenes."

In order to maintain the integrity of Alex Garland's script, the filmmakers opted for MiniDV, a format at the lower end of digital video's resolution scale. The advantage of MiniDV, however, was that its inherently small cameras could be set up quickly, which proved key to pulling off the stunning shots of deserted London....

Choosing the MiniDV format wasn't just about logistics. Its harsh imaging characteristics corresponded well with the film's subject matter....

During preproduction, Dod Mantle performed extensive image tests in conjunction with Moving Picture Company in Soho, London, to achieve the best shooting combination for a filmout. MPC believed the best results occurred with footage shot in the 4x3 aspect ratio but matted for 16x9 by the PAL XL1 (625 lines of resolution, 900,000 effective pixels over three 1/3" CCDs) in Frame Movie Mode, its pseudo-progressive-scan method, which is performed electronically within the camera. "My post house was quite adamant that it would help in their work to maintain as much quality as possible from the original material," the cinematographer says...

Dod Mantle helped matters by securing the higher-resolving Canon EC (6-40mm) and Canon EJ (50-150mm) prime lenses to the camera bodies with Optex adapters....

Dod Mantle shot as wide open as possible with ND filters to minimize DV's seemingly infinite depth of field, and he underexposed by one to two stops to get more information on tape.. For daylight-exterior shots that featured prominent skies, which present difficulties in DV, grad filters were thrown into the mix... Dod Mantle shot sky plates to use as replacements in post by stopping down three to four stops and using filters to enhance the cloud formations.

All footage was upconverted to D-1 tapes (125 in all) by Clear Ltd., who also handled the visual effects. D-1 provides YUV 4:4:2 uncompressed PAL images. (The PAL Canon XL1 is 4:2:0.) After editing and conforming, the seven D-1 masters were handed off to MPC, where Dod Mantle spent almost a month in tape-to-tape grading with colorist Jean Clement Sorret, who used a Pogle Platinum and a Cintel DSX with the PiXi secondary color corrector. The graded masters were captured onto a digital disk recorder for treatment on a Linux Shake workstation. Running through MPC's proprietary FilmTel software, the 16x9 images were enhanced and interpolated to 2K files, blown up slightly to 1.85:1, then recorded onto grain-free Kodak Vision Color Intermediate 5242 stock via the Arrilaser. The answer print was created by Technicolor London on Fuji HiCon 3519D. Deluxe handled the release prints on Vision 2383.

RES: What were other benefits of using digital cinematography for this film?

BOYLE: The biggest benefit, to be absolutely honest, was the London sequences, because we would not have been able to afford to do those on celluloid and not only that, they would have been, in their very nature, completely different. If we were working with a celluloid camera, with the number of people you need to operate that, it would have been either much less ambitious or staggeringly expensive, in which case the film would have been very different, in part because we would have had to have a star in it to pay for it.

RES: What about disadvantages?

Boyle: Picture quality, especially on wide shots. We were fortunate; on the whole we got away with it. When you dwell on a wide shot, the human eye is so extraordinary that it goes to where it is interested on that big screen and it zooms in, just like that zoom in on the video game. Halo! If the eye is interested in that picture and if the detail isn't there, it looks a bit shitty. Whereas on film, you can go in that close and there's enough detail there so it is still acceptable. That's the only major disadvantage. I am not sure if DV would work for period films as there is something completely modern about its feel and about it as a recording or capturing process. If you did a Jane Austin novel or great period piece, I don't know what it would look like; it might feel very odd.

Progressive scan mode: I thought the GL1 had a progressive mode, but it actually doesn't. Xiao-qing Wang sent me the following from a Canon rep:

"The GL-1 does not have a progressive scan CCD chip, instead it features an Interlaced Scan CCD. The Normal Movie Mode captures two fields (odd and even), then interlaces them together for playback. The time delay in scans creates a loss in vertical resolution and decreased sharpness of the still images. In contrast, the Frame Movie Mode captures 3/4 of a frame and interpolates the other 1/4 at the same point. Since both scans are effectively taking place at the same time, vertical resolution is 1.5 times higher. This produces high quality still images, but not quite the level of a camera with a Progressive Scan CCD."

The GL1 30 fps "frame movie mode" video looks quite good, usually, and to my mind is useful for video in a way that the TRV900's 15 fps prog.scan mode is not. The actual shutter speed is 1/60 (or higher) in this mode, so the camera is in essence recording only half the time, but for many subjects this is ok.