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Transfering film shot at 18 fps


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#1 Taki Bibelas

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Posted 23 November 2005 - 02:03 AM

I have some 16mm and super 8 both just shot at 18 fps (as there was no sound and to save stock). Now that I'm in contact with a couple of transfer places for the TC, they tell me there machines run at 24fps so my films will look sped up when I see them in my editing program that is set to 25fps. Thats normal, but can't they just do the TC at 18 fps?

If I were to project it and video tape it ( I wouldn't ) it wold come out at the correct speed on the computer.
I don't want to have to deal with slowing down images in post to get the speed correct.

What is the best way to transfer material shot at 18 fps ?
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#2 David Mullen ASC

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Posted 23 November 2005 - 02:22 AM

There are plenty of telecines that can play the footage at 18 fps -- just keep asking around.

Now I suppose if this a transfer to PAL, there is some advantage to transferring at 25 fps -- then you have one frame of video = one frame of the original film on the master tape. You can then add your own speed correction in your editing system. But it may be easier just to get the footage transferred at the shooting speed.
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#3 Will Montgomery

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Posted 27 December 2005 - 12:00 AM

Video Post & Transfer in Dallas, TX can definitely do it. They've transfered 16mm shot at 16 fps to regular miniDV and corrected for the speed. They actually do it really well, they have something called "Metaspeed" that they developed that allows this. But David is right, any pro telecine place should be able to help you with that problem.

www.videopost.com

I don't work for them, just use them on a regular basis with good results.

p.s. That's for 16mm... for Super 8 (and 16mm) talk to the guys at www.fstp.com. They have great service too and don't mind talking to you.

Edited by Will Montgomery, 27 December 2005 - 12:02 AM.

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#4 timHealy

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Posted 27 December 2005 - 12:29 AM

I just sent some Super 8 shot at 24 fps to be transferred at 18 fps to http://www.posthouse.com/. It is my first time with them but I understand they have a wetgate to help keep scratches down to a minimum. It would probably be more helpful to older film, but what the hell.

best

Tim
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#5 videoFred

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Posted 29 December 2005 - 05:39 AM

Hello,

There are several ways to go:

1) Frame accurate transfer: one filmframe= one videoframe.
Transfer speed does not matter, here. Frame rate of the transfered file also does not matter at all.
It's very easy to change frame rate of a frame accurate transfer.
It does not change anything, it just change play speed of your file.
So, in your case, just set frame rate to 18fps.
This file will play fine -at the right speed- on any computer.
You need a transfered avi file on data DVD, then.
You need a frame rate conversion to let it play at the right speed for stand alone video-DVD use.

2) Real time transfer: the transfering machine runs at the desired filmspeed, in your case, 18fps.
But the capture camera runs at 25fps(PAL) or 30fps (NTSC).
Depending on the number of blades on the projectors shutter, the used system (PAL-NTSC), and the shutter speed from the capure camera, you get flickering. Can be solved with electronic speed regulation on the projector and some tweaking of the camera settings. Then the camera does the 'pulldown' for you, in real time. Then you end up with a 25 or 30fps file, but running at the -almost-right play speed. But then you also have a file with duplicate frames...

3) Frame accurate transfer, but with frame rate conversion at the same time.
No matter the speed of the transfer, the output is always (hardware) frame rate converted, very often with special interlacing and duplicate patterns to give smooth playing files. The Flashscan8 works like this. The speed of the transfer is the play speed of the resulting file, but this file is always 25fps...


4) Frame accurate transfer, but with frame rate conversion afterwards, with your own software.
Most NLE programs will do the same as mentioned above: adding duplicates with mathematic patterns, depending on the play speed settings. For example: 18.75 to 25 is a 3 to 4 pattern. Every 3 frames, you get one duplicate.

Another software approach is motion estimation: the software analyses motion, and creates entire new frames. Then you have a real 25fps file, no duplicates, but 25 different frames, calculated by the computer. With this software you can convert any frame rate to any frame rate. Extreme slow motion is possible, too.
But it is not 100% perfect for now.. Sometimes it gives strange artefacts. However, I use this all the time, now. My files are playing very smooth, this way.

Fred.

Edited by videoFred, 29 December 2005 - 05:46 AM.

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#6 Stephen Williams

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Posted 29 December 2005 - 10:11 AM

Hi,

I had a problem once with S8 shot at 25fps, the facility default transfer speed for S8 was 18fps. They had never heard of anybody wanting 25fps....... They own a film lab as well and thats hopeless too!

Stephen
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#7 David Mullen ASC

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Posted 29 December 2005 - 11:58 AM

Hi,

I had a problem once with S8 shot at 25fps, the facility default transfer speed for S8 was 18fps. They had never heard of anybody wanting 25fps....... They own a film lab as well and thats hopeless too!

Stephen


Probably because it was a film chain device using a Super-8 projector pointed at a video camera, more or less. That would be limited to Super-8 projection speeds, usually 18 fps and sometimes 24 fps on most projectors. Any standard telecine can run at 25 fps.
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#8 Stephen Williams

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Posted 29 December 2005 - 12:56 PM

Probably because it was a film chain device using a Super-8 projector pointed at a video camera, more or less. That would be limited to Super-8 projection speeds, usually 18 fps and sometimes 24 fps on most projectors. Any standard telecine can run at 25 fps.



Hi,

It was a FDL 90 with a Pogle!, they just do not have a clue what they are doing! I then went to a Spirit with a S8 gate, the trainee colorist spent 2.5 hours color correcting 30 minutes of material, I only got charged for half an hour one light pass!

Stephen
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#9 Clive Tobin

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Posted 29 December 2005 - 08:33 PM

Probably because it was a film chain device using a Super-8 projector pointed at a video camera, more or less. That would be limited to Super-8 projection speeds, usually 18 fps...


Almost nobody can transfer super-8 film at 18 FPS without flicker apart from high-end equipment. About the only things known in the USA that would run at this speed into video without flicker are the Sony BM2100 (which stuttered between 15 and 20 to average out at 18), the Kodak Videoplayer VP-1 (a jump-scan flying spot scanner which worked great for the first few hours except for vertical quiver) and rotating prism gadgets like the Goko (a glorified movie viewer.) Some people have done severe projector butchery to put in a 10-bladed shutter to run 18, but this requires a very fast pulldown which is noisy, unreliable and hard on the film.

Most people are running at 19.98 FPS with a 3-bladed shutter to equal the 59.94 video field rate and get no flicker. (19.98 x 3 = 59.94.) Our TVT-8 G Type video transfer machines do this. We have a 4-bladed version for regular-8 film (which was mostly originally shot at 15-16 FPS) running 14.985 FPS. The PAL versions run at 16-2/3 FPS with 3-blade.

Our TVT-8 H Type transfer machines use a variable blade count using electronic shuttering to get the various speeds. The basic speed is 17.126 FPS using a 3-1/2 blade shutter. (17.126 x 3.5 = 59.94.) It can run half speed using an equivalent of 7 blades, or 1-1/2 times speed by reverting to a 2-1/3 blade shutter. The PAL versions run at 8-1/3, 16-2/3 and 25 FPS using different math.

The 2-1/2 or 5-blade shutter of legend is for transferring film at 24 (actually 23.976) FPS to NTSC video.

(These are the numbers for NTSC. For PAL, most people transfer at 16-2/3 FPS with 3-blade or 25 FPS with 2-blade to get 50 Hz.)

Other equipment has been made overseas, principally for PAL, but it was never promoted here and is mostly unknown in the USA.
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#10 videoFred

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Posted 02 January 2006 - 08:18 AM

Almost nobody can transfer super-8 film at 18 FPS without flicker apart from high-end equipment.


No doubt about your wonderful machine and your knowledge.
But flicker-free is very well possible, even with a simple webcam.
With frame-by-frame capturing! (see example movies on my website)
Example frames on my site are taken with a Philips 640x480 webcam,
example movies are taken with a 1024x768 machine vision cam.
Movement of the movies is not 100%... I'm working on this.

It is very well possible to capture each frame as a bitmap, for top quality.
Here's a bitmap, I took with my machine camera: (1976, Super-8, Kodachrome, location: Bermuda)
http://users.telenet...map/sailing.bmp


Many people (not you, Clive) are mixing transfer speed and play speed of the resulting file.
Transfer speed of a Tompson Shadow, at high quality, is... 5fps.

IMHO transfer speed only matters for real time transfers.

Fred.

Edited by videoFred, 02 January 2006 - 08:23 AM.

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#11 Mike Crane

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Posted 12 January 2006 - 01:37 PM

Here is another place I use for both 16 and super 8 work: Spectra Film. They have a souped Rank with Da Vinci that delivers a great picture. Their Meta-speed will run their Rank at any frame rate you wish - including 18fps.
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