Editing 18fps in NLEs

[Anthony Brock]

I want to shoot super 8mm film at 18fps because I love the look. The final output media will be for computer playback only. I've spent countless hours scanning forums looking for a 18fps to NLE work flow but all the info seems to center around 24fps destined for ntsc or pal television playback.

 

Can I shoot super 8mm film at 18fps, then have it scanned and edit it in an NLE without any sort of work flow that involves frame blending?

 

From what I understand, the frame-by-frame scanning equipment like the Moviestuff gear handles 18fps well by adding some exotic pulldown. Would I import this to my NLE as 29.97 or 23.976, or 24? Then, would I have to be careful about which frames I cut on?

 

To aviod this, would it be better to have my 18fps footage scanned at 24p, edit it in my NLE at 24p and then do the pulldown on output? What would I use to putput a 24p timeline to 18fps media files that can play on computers? If I don't mind the slight slow motion, can I output the 24p timeline to 15fps computer media and keep all frames. I mean, can I achieve 15fps output with a method that doesen't cut out frames but instead simply uses all the frames I shot but play them back at 15fps by extending my video?

 

Also, is it correct that rank systems aren't set up for 18fps? I ask because I want to shoot with negative stock and the maker of Moviestuff gear say's it can't handle negatives (although I've found one house that claims it has found a workaround for using the Moviestuff gear for negative film).

 

Again, to be able to use rank transfers, could I have my 18fps footage scanned at 24p, edit it in my NLE at 24p and then do the pulldown on output?

 

Help!

[Jim Train]

Interested in this as well. Anyone have anything to offer on the subject? I have several family films shot at 18fps that I would like to have transferred and I plan on editing them using Premiere Pro, am I doomed?

[Marc Marti]

If your film is tranferred as a series of still picteres (tiff, jpeg,targa...) you can set your timeline at the speed you prefer.

But for making compatible files with DVD or Blu-ray you have to use the standard speeds (24, 25, 29,97) so unavoidably you have to duplicate frames in the end...

[Robert Houllahan]

Most NLE's will not have 18fps as a time-line option, in fact I don't think any do, so you will have to speed change the transfer one way or another. In the old days of NTSC you would have the Telecine run the speed at 18fps and the resulting video would be 29.97 frames and some of the film frames would be blended.Now with 24P HD you can have the film frames transferred 1:1 and then change the speed of the clip WITHOUT blending frames and you will have the 18fps cadence in a 24fps time-line without frame blending.

 

-Rob-

[Jim Train]

Lord, that sounds complicated! I am approaching 60 and only started using editing software last year so I am somewhat daunted but the undertaking to transfer 18fps footage. Will the telecine company be able to assist in this or should I just perhaps transfer the footage as 24fps? I didn't realize it was so complicated to get 18fps footage into an editing programme.

[Wooda McNiven]

I'm no expert in either editing or telecine... but I've dabbled. I have a Moviestuff Workprinter XP and its not this equipment that determines final frame rate, its the Cinemate capture software that let's you set the desired frame rate, e.g. 18 or 24 fps among others. Not really knowing what I was really doing, I have taken some of my material (set at 18 fps in Cinemate because that's the speed it was originally shot at) and imported it into I-Movie and Final Cut Express (and I think Vegas too), and was able to work with it just fine.

[Phil Rhodes]

You might try frame-duplicating it up to 24, cutting at that rate, then using an automatic duplicate-frame removal tool. There are filters for AVIsynth that will do both the duplication and the de-duplication, and after a bit of initial messing about to create the necessary scripting it is a reasonably drag-and-drop operation.

 

P

[Freddy Van de Putte]

For computer use and for the digital master files of your transfered film, the best way to go is one film frame = one digital frame. Progressive, no interlacing. This way, your master file is a digital copy of your original film. Frame 1022 on your film is frame 1022 on the digital file. Use a losless codec for the master files. Huffyuv is a very good one and it's free.

 

Later, if you need 25fps for DVD for expample, you can do this in post. It is important to have the original film frames on the digital master file.

 

The problem with NLE's is the fact that it all happens on the background. It is better to have full control over the frame rate conversion.

 

Play speed is one thing, frame rate is another thing. :o

 

Assuming a one film frame = one digital frame file, then play speed is just a number, telling the computer how many frames/sec it must display. Easy enough to change this with VirtualDub for example.

 

Changing the frame rate is only needed if one wants to make a copy of the file in a standard format that needs another frame rate like standard PAL (25fps) for example. The problem is always the same: we must change the frame rate without changing the original play speed.

 

There are three ways to do this:

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1) adding duplicate files, this means some frames will be showed twice.

 

2) blending: the computer will create intermediate files with info from the previous and the next file, but only on parts with high motion. The more motion, the more blending.

 

3) interpolation: the computer will draw complete new frames, based on motion analysis. Only a few original frames will be left over.

 

It is possible to convert any play speed to any frame rate, and it can be all done with Avisynth. A correct prepared 18-25fps clip will not be changed by your NLE any more. The NLE will accept it as a standard 25fps file. If you render it to Mpeg2 (DVD) it might add interlacing, but you can force it to render progressive.

 

On high motion scenes, I use frame blending. On low motion scenes, I use interpolation. See my examples on Vimeo.

 

Because I always keep my frame accurate progressive masters on portable HD's and on several backup computers, I can always change them later to another play speed/frame rate. (HD for example)

 

Hope this helps, ;)

 

Fred.