On slating

[Actor]

When syncing film to sound you are supposed to match the sound to the first frame where the upper part of the clapper is not blurred. OK. If you have transferred your 24fps film to 30 fps then every fourth frame is going to be doubled. What if the sync frame is the one which is doubled? Do you match the sound to the first frame or the second? Statistically we can expect this problem to arise on one take out of every four.

My own inclination is to match the second frame on the theory that the previous four have gotten progressively behind and the second of the double frames is more accurate. Of course it could be argued that, having seen the clapper strike, the audience will percieve the sound as being out of sync if it comes on the later frams. But the audience is not going see or hear the clapper strike. That part is going to be cut out anyway. Hopefully we are going to match what comes after.

None of the editing books I have read address this problem since they all deal with editing film and fullcoat. Does anyone know if there is a standard practice regarding this?

[Matt Pacini]

I'm not totally clear on your question, but to clarify a little, 3:2 pulldown does NOT double every fourth frame.
I'm not sure why this keeps being repeated all over the internet, but it's more complicated than that.
What it does to make the extra 6 frames per second is, that it borrows a field from one frame, and a field from the next frame, and combines them into a new frame and inserts that between the two it stole from.
So what you have is an extra frame made of the fields from two frames, which is different than simply doubling, and it looks different too. (smoother and not noticable).

Anyway, you don't sync up to the clapper being open, if that's what you're saying. You're syncing to the clapper in it's closed position, because that's when it makes the sound of two pieces of wood slamming together.
That's the sound that you're listening for (or looking at a waveform of on your monitor) to sync up. It doesn't always have to be a slate too:
I've synced up to doors slamming, coffee cups being set on a table, etc. You just need something with a sharp attack in the audio to sync the visual up to.
So the 3:2 pulldown issue is irrelevant to this; get to the frame that you can SEE where the slate is closed, and line up the start of the slating "whack" in your audio right on that frame, and you're all set.
Even if you're one frame out, that's close enough.
Two-three frames, you'll notice, but not one frame.

Matt Pacini

[MovieStuff]

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by Matt Pacini:
3:2 pulldown does NOT double every fourth frame. I'm not sure why this keeps being repeated all over the internet</font></td></tr></table></td></tr></table></BLOCKQUOTE>

Because some of the older Ranks did, indeed, double every fourth frame for transfers to NTSC! (which is why so many early commercials were shot on film at 30fps) I've got several 16mm films that were Ranked and they do not have the split field combinations on the artificial frames. And these were films a customer had transferred only a couple of years ago, while I've got some older films that have the split field combination on the pulldown frames, so there's no chronology to it.

Also, if your NLE is set to display fields and not whole frames when the cursor is stationary, then it will *appear* like every fourth frame is doubled, even if it has the split field combination on the pulldown frame. A lot of peoples NLE systems are set to field and not frame and they don't even know it, so it's easy to assume that the fourth frame is doubled when it really isn't.

And, finally, I am probably somewhat the culprit for propogation of the doubled fourth frame explanation. A lot of people don't understand how 24fps can be stretched to 30fps. While some Ranks do use the split field combination, explaning to people that the fourth frame is doubled makes it easier for them to understand, mathmatically. Heck, a lot of these same people aren't even aware that video even HAS fields, so the split field explanation immediately confuse the issue at hand, which generally isn't about how video works but, rather, about some other unrelated technique.

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by Matt Pacini:

What it does to make the extra 6 frames per second is, that it borrows a field from one frame, and a field from the next frame, and combines them into a new frame and inserts that between the two it stole from. So what you have is an extra frame made of the fields from two frames, which is different than simply doubling, and it looks different too. (smoother and not noticable).</font></td></tr></table></td></tr></table></BLOCKQUOTE>

Not that different, actually. I mean, it IS smoother but it isn't like night and day and there is a sacrifice of resolution when you use split field pulldown frames, so there's a trade off. We use whole frame pulldowns on the DV8 for transfers of 24fps. It looks natural and retains maximum resolution on every frame. If the action moves really fast you can sometimes notice the difference but, overall, all our clients so far like the look and a lot of people feel it helps to retain a more "film" feeling to it and that it looks less "video-ey" (for lack of a better term).

And, again, even the pulldown pattern you described isn't the only pulldown scheme out there. I've seen some that start the split field interpolation as far back as the third frame of the series, which is almost ridiculously smooth and, I think, robs the image of too much resolution since you start to lose the frame discretion that is what really gives flying spot scanners their clarity (not just the fact that they are using a flying spot to scan the film). As such, the DV8 maintains its clarity for the same reason; it maintains frame discretion which using whole frame pulldown will provide. Split field pulldown frames can not provide full resolution by the very nature of how they are formed. So, right off the bat, there is about a 25% loss of potential resolution when using split field combinations.

None the less, I am currently working to see if I can integrate Jeff Dodson's excellent DodCap software into the DV8 operation so that I can give people a choice of split field or whole frame pulldown. My ideal goal would be to use whole frame pulldown on more static scenes that would benefit from the higher resolution and switch over to the split field pulldown on scenes with rapid motion, where the sacrifice of resolution would not be as noticable. Unfortunately, his software won't work on my ancient NT system so I'm looking to upgrade.

But the long and short is that there are a variety of pulldown schemes out there and no "one" scheme is considered the "proper" way to transfer film. There are a lot of people that think any kind of pulldown scheme is a cludge and prefer the super smooth look of a telecine projector with 5 blades, maintaining that only a projector can give you accurate film motion as it was meant to be seen. I would actually tend to agree with that statement; any projector results in natural motion compared to any flying spot transfer to NTSC video, unless the film was shot at 30fps to start with. But, again, there is that sacrifice of resolution due to a lack of frame discretion.

[Actor]

I am aware of the differences between frame pull down and field pull down.

I have examined a couple of VHS movies frame by frame and (if time code is to be believed) frame pull down is the one used in both, i.e., every fourth frame is doubled.

We had one client who wanted to use iMovie to slow down the action of a 24fps movie. It did not work because every frame was doubled, meaning the fourth frame was quadrupled and there was a quite noticable three times / second pause in the action. I was able to delete every fourth frame of the clip. After this applying slow motion produced a smooth action.

As I understand field pull down it works like this. Four frames of film have to become 10 fields of video. If we label the film frames F0 .. F3 and the video fields V0 .. V9 then:
<ul type="square">[*]V0 .. V2 are taken from F0[*]V3,V4 are taken from F1[*]V5 .. V7 are taken from F2[*]V8,V9 are taken from F3[/list]
Thus:
<ul type="square">[*]V0 and V1 make up a video frame that is a copy of F0.[*]V2 is an orphan field copied from F0[*]V3 and V4 make up a video frame that is a copy of F1. This frame straddles the normal frame boundary, i.e., the even numbered line are written to the sceen first, followed by the odd numbered lines, the reverse of the usual sequence.[*]V5 and V6 make up a video frame that is a copy of F2 and which straddles the frame boundary.[*]V7 is an orphan frame copied from F2.[*]V8 and V9 make up a video frame that is a copy of F3.[/list]In effect F0 and F2 are made to last twice as long when transferred to video.

[MovieStuff]

Well, your description is close. If you're talking about whole frame pulldown, then the pattern would be like this (it doesn't matter where the pattern starts, frame wise):

We'll call the frames "A" "B" "C", etc and the fields 1 or 2 only, since that's how fields are referred to in video.

In whole frame pulldown, this is what you'd get:

A(1,2) B(1,2) C(1,2) D(1,2) D(1,2) E(1,2)

Now, as mentioned, there are a couple of pulldown schemes that use split field combinations or interpolated frames. Here is the easiest one to explain:

A(1,2) B(1,2) C(1,2) D(1,2) (D1+E2) E(1,2)

As Matt correctly described, the fifth position contains a frame that uses fields from both the original fourth and fifth frames. Specifically, it uses the first field of frame four and the second field of frame five to create the artificial "in between" frame.

Also, there is at least one other pulldown scheme I have encountered off of a scanner type transfer with the combination of fields starting as far back as frame number 3. I've run into this pulldown scheme several times while doing film restoration work for a distribution company and it was really difficult to edit and work with, in my opinion. Also, I find that any sort of split field combination robs the image of a bit of clarity since the frames with the field combinations are not full resolution. But, on scenes with fast moving subjects, it does smooth out the action better. On "normal" scenes with slower movement, I prefer the whole frame pulldown as it (to me, at least) retains a more "film look" in the motion.