It’s a common dilemma in the UK for filmmakers: do you shoot at 24 or 25 frames per second? Until a couple of years ago, I would have said 25 every time, but with DCPs and Blu-rays now about, and most TVs capable of handling a range of frame rates, the answer is not so clear-cut. Unlike aspect ratio or shooting format, the decision has no discernible creative impact on your project, merely a technical one. And it’s so easy to convert between the two that it often feels like it makes no odds. Nonetheless, to help anyone on the horns on this dilemma, here’s my round-up of the respective advantages of each frame rate.

The Case for 25fps

• If you need to record to any kind of tape format at any point in your process, 25fps is what you need.
• The same goes for PAL DVDs.
• If your film is going to be broadcast on UK TV, it will be transmitted at 25fps.
• Since your camera’s running in sync with the UK mains supply’s alternating current, you don’t need flicker-free ballasts for your HMIs. Having said that, pretty much every time I’ve hired an HMI, it’s come with a flicker-free ballast as standard anyway.
• If you’ve made a 25fps feature film that isn’t quite long enough for distributors to classify it as a feature, the extra running time you squeeze from exhibiting it at 24fps might make the difference.

The Case for 24fps

• For maximum compatibility, Digital Cinema Packages should be authored at 24fps.
• The same goes for Blu-rays. (Blu-rays do not technically support 25P, but they support 50i, which can contain progressive 25fps content. However, discs authored to the 50i spec apparently will not play on most US machines.)
• If you shoot at 24fps and need to convert to 25fps for any reason, your film will become 4% shorter, making it that extra bit pacier and able to squeeze into a shorter slot at a film festival.
• If shooting on film, your postproduction facilities will be much more comfortable with 24fps material. We really freaked out our lab on The Dark Side of the Earth by shooting 25.
• Many traditional film projectors will only run at 24fps.

Can you think of any other factors that I’ve missed?

I’d say the balance has tipped in favour of 24fps. However, I think you’ll find that many people in the UK (outside of the celluloid world) are still more comfortable with 25…. for now.