G DVC FilmStyles 24p plug-in
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Tech Specs:
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When to use:When you are working with 60i (or 50i PAL) video footage, and you want the motion in your project to look more “filmlike”. |
Does the plug-in actually change the frame rate?
No, it just changes the appearance of the motion of the video so it looks like it was shot in 30p, 24p or 25p (PAL).
What setting should I use?
If you use the 30p setting (or 25p for PAL footage), the resulting video will have no interlacing and so will be perfect for delivery on a computer or mobile device screen, and will also be great on TVs.
The 24p setting adds 3:2 pulldown interlacing, so it should only be used for television delivery– DVD or broadcast projects you want to look like they were shot on film.
So, if delivering only on TVs, you can use either 24p or 30p (or 25p for PAL). For all other projects (computer screen and/or mobile screen delivery, only use 30p (or 25p for PAL).
I’m not altogether sure what interlacing is.
Well, that’s not really a question, but here’s some info on interlacing:
A format that records alternating fields is called “interlaced”. In video format nomenclature, this is abbreviated as lower case “i”, hence “60i” and “1080i” are interlaced formats.
A digital camcorder, when switched to 60i mode, takes a picture 60 times every second. But it doesn’t store the whole picture, instead, it only stores every OTHER line of the image. This is called a “field”. A 60th of a second later, it takes another picture and stores the OTHER lines, the INBETWEEN lines. Together, these two fields make up one frame. Rinse, lather, repeat, and you have a standard interlaced video stream- even lines, odd lines, even lines, odd lines.
Waitaminit…
Why interlace video in the first place?
Well, interlaced video requires only half the bandwidth and half the storage space- because it’s only storing every other line of the image. That means, for example, you get twice the recording time on a portable card or hard drive. You can send a file to someone over the internet in half the time.
What is Temporal Resolution?
Temporal resolution, which I’ll call “TR” for short, is the number of times an image appears to change each second. You could think of the TR as the “perceived frame rate”.
It’s good to know, as you work with different types of video footage, that the TR, is often not the same, as the actual frame rate.
Interlaced NTSC 60i video has a TR of 60, because every second, you can see something move 60 times across the screen- once for each field. Yet the frame rate is 29.97 frames per second, because each two fields make up one frame.
Film has a TR of 24, because you see a subject change position 24 times every second. However, projecting only 24 frames per second in a dark theater is too flickery. So theater film projectors have shutters, that actually show each frame of film twice. Some even show each frame three times. So when you see a movie in a theater, you’re actually seeing 48 or 72 frames projected every second, but the image is only changing 24 times per second- every 2 or 3 frames. So the frame rate might be 48, but the TR, is still 24.
Camcorders have a lot of buttons and switches, and some of them say things like 24p, 30p, or 60i. Marketing departments usually call these “frame rates”… and sometimes they are, with some camcorders, when you switch them to “24p” or “30p”, they’re actually recording a simple 24 or 30 full frames per second.
Other camcorders, when you shoot in 24p or 30p mode, do take 24 or 30 snapshots every second, but then, when they store the video, they duplicate each frame to two or three fields, so that they’re actually recording a 60i video stream. This trick makes it easy to deliver on DVD or broadcast because you’re dealing with normal 60i video technically, but it LOOKS like 24p or 30p to the viewer.
How do different TRs change the artistic effect of my project?
Think about all the different TRs you might watch in one day. Today, you might watch a 15 frame per second web video, a 24 frame per second movie in a theater, your Canvas window at 30 frames per second, a basketball game on TV at 60 fields per second, and a video game at 100 frames per second. That’s 5 different TRs in one day- from 15 to a hundred!
As the TR gets slower and lower, motion looks more choppy, more stroby, more staccato, until, somewhere around a few frames per second, the illusion of motion breaks down completely and video just looks like a slide show of still images.
The FASTER the displayed frame rate, the more fluid, smooth, and realistic motion appears, up to a threshold of about 70 or 80 frames per second, where the individual frames fuse together and human vision simply perceives the stream of still images as perfectly smooth, continuous motion.
So you can see that the 60 field per second rate of NTSC is close to the top of the range, which is why it essentially simulates reality to the human eye. (Which is why, of course, reality TV shows are shot at 60 fields per second!)
Not surprisingly, if you shoot 35mm film at 60 frames per second, and project it at 60, to the audience, it looks like video, not film.
Viewers associate 24p with film and high budgets
People tend to associate the 24p look with movies and high budget television, like prime time dramas and Jaguar and Obsession commercials. People associate 60i with shows like news, reality shows, sports, and so on. 60 can also look cheap, because everyone’s seen home video shot at 60.
So, due to the conditioning of your audience over the last century, 60 field video, no matter how beautiful the lighting and cinematography, will NEVER, ever, ever look like film. Your movie might look like the most gorgeous soap opera ever, but it won’t look like a movie to your viewers at 60i. Your commercial will look local, not national. This association has been ingrained into your viewers minds since the first time they went to a movie theater as a little kid, and it’s not going away anytime soon.
What’s wrong with 24p?
24p is pretty choppy. During moving camera shots, most every part of the picture is changing every frame. At 24 frames per second, a medium speed camera pan or move is almost unbearably choppy; usually unusable footage. You won’t see many medium speed camera moves in Hollywood movies cause film camera operators are trained in film school to never do that.
The other disadvantage with 24 is when it’s broadcast, 24 frames have to be spread out over 60 fields. If you have 23.976 full frames, that need to go onto 59.94 fields, this is exactly equal to 2 going into 5, that is, 2 frames need to be distributed to 5 fields. Clearly, the smoothest possible way is putting the first frame on 2 fields, and the next frame on 3 fields. This is called “24 with 2:3 pulldown added”. The fact the images are shown at unequal intervals, 2 fields, 3 fields, 2 fields, 3 fields, results in a kind of weird-looking jerky movement called “motion judder”.
You’ve seen 3:2 pulldown a lot. Pretty much every movie, commercial, drama or sitcom you’ve ever watched on TV that was shot on film or 24p video had to have 3:2 pulldown added before sending out over cable or satellite.
Although I must mention that more and more TVs sold nowadays have circuitry that automatically detects and removes the repeated fields from the signal on the fly, so footage that was originally 24 actually displays at 24. So every day, this becomes less of an issue as people buy new TVs.
Is 30 “the new 24″?
Overall, I prefer shooting 30p to 24p for most projects. Because 30 has 25% more frames per second than 24, 30 is a little smoother on camera moves, from panning and tilting to steadycam or handheld shots. With 30p, you still have the cool filmlike stroby look, but a little less choppy than 24.
Plus, if you ever have to convert your project to 60i, for DVD authoring, broadcast, to mix with legacy 60i footage, or any other reason, each image is shown for exactly 2 fields, so the motion is even and you’ll never have motion judder.
What is the 60i look good for?
If you’re delivering a project that will be watched on television sets, 60i, or 50i in a PAL country, is the best choice for some projects.
For one thing, since you’re seeing motion 60 times every second, 60i is the best format to use when motion needs to be shown as smoothly as possible. A sporting event, like a basketball game or a tennis match, or a how-to DVD on martial arts, golf or skiing would look the best at the higher TR of 60i.
When you want a DVD project to have the video look of a TV news, a reality show, soap opera, cooking show, game show, workout video, home improvement show, sporting event or documentary, use 60i.
This is the ONLY situation where you want to deliver 60i video to your viewers- when you want the 60i look and feel, and when they’ll be watching your project on TVs, or mostly on TVs.
What frame rate should my final exported movie be?
Let’s sum this up:
Broadcast
If your project is going to broadcast, it has to be 60i. In a PAL country it has to be 50i. It can have a TR of whatever you want, like 24, 25 or 30, but the actual technical format must be 60i, or 50i in a PAL country.
DVD
If your project is going to DVD, it can either be 24p or 60i.
Computer/Mobile
If your project is going to be played only on computers, or portable viewing devices, it should be be a straight, non-interlaced 30p (or 25p if you shot on PAL).
