workprinters at 18fps?

[Rick Palidwor]

I know that many transfer set-ups, especially old-school "film chain" set-ups, have to ramp 18 fps up to 20 to avoid flicker. Is this the case with the worksprinters or can they transfer 18 at 18 without flicker?

And what about other high-end scanning services? Can I presume they can run 18fps flicker-free?

Thanks
Rick

[brightlight]

The WorkPrinter is a frame-by-frame transfer that runs flicker-free at whatever rate the film was shot. Each frame of film is one frame of video. Of course video runs at 30 fps, so the Workprinter file need to be altered in Permier or Final Cut Pro. The speed is changed in playback (80% total playback speed if it was shot at 24 fps, 60% total speed if film was shot at 18 fps, or 50% total playback speed if it was shot at 15).

[Rick Palidwor]

Thanks.
I supppose if you go into a 24 fps digital time line you wouldn't have to alter it at all.

When you adjust the speed, say, 80%, is it noticeable? Does it repeat the occassional frame? How does it compare to the kind of pull-down pattern (might have my terms wrong) of old-school transfers, wehreby certain video frames were duplicates of the surrounding frames, one frame on each field of the video frame?

Rick

[brightlight]

Thanks.
I supppose if you go into a 24 fps digital time line you wouldn't have to alter it at all.

When you adjust the speed, say, 80%, is it noticeable? Does it repeat the occassional frame? How does it compare to the kind of pull-down pattern (might have my terms wrong) of old-school transfers, wehreby certain video frames were duplicates of the surrounding frames, one frame on each field of the video frame?

Rick

Yes, if the film was shot in 24 fps, and you brought it into a 24 fps timeline, you would not have to alter the speed.

The only time frames are added. is you you check off a little box (this is in FCP, I'm not sure about Premier) that says "Frame Blending". If you leave frame blending off, the speed altered file will still be "progressive" (ie; each frame of film will still be one frame of video)

[MovieStuff]

Thanks.
I supppose if you go into a 24 fps digital time line you wouldn't have to alter it at all.

If you shot at 24fps, then each frame of film will be on a separate frame of video and no speed change would be necessary. If you put the film on a standard NTSC timeline then you will need to apply the appropriate pulldown pattern unless, of course, your film was shot at 30fps! ;)

When you adjust the speed, say, 80%, is it noticeable? Does it repeat the occassional frame?

It depends on what you use to change the speed. If you use Premier at 80%, it will simply double every fourth frame to create 6 additional artificial frames which, added to the original 24, will stretch 24 frames of film across 30 frames of NTSC video. However, if you use CineCap, then it will use the industry standard pulldown patterns (2:3, etc) where the frames are spread evenly across 60 fields as opposed to only 30 frames. In the case of 24fps, one film frame would be on 2 fields and the next film frame would be on 3 fields, etc. There are different pulldown patterns for each speed required but doing it on a timeline will not necessarily be the same thing, though it can look okay.

How does it compare to the kind of pull-down pattern (might have my terms wrong) of old-school transfers, wehreby certain video frames were duplicates of the surrounding frames, one frame on each field of the video frame?

See above. CineCap lets you use interlaced or non-interlaced pulldown patterns. So you can use the classic 2:3 pulldown for 24fps as described above (interlaced) or you can have it simply duplicate whole video frames (non-interlaced). Some people mistakenly believe that using the non-interlaced pattern will play better on a regular CRT television but that really is not the case. You are always watching 60 fields go by on NTSC, even if you are watching a progressive scan movie from a DVD. If you spread your 24 frames across 60 increments, you still get full resolution of each film frame but the motion plays smoother. If you spread your 24 frames across only 30 increments, the resolution does not increase because you still are seeing two fields minimum of any given film frame but the motion will simply be more jerky. Now, if you are watching on a progressive scan monitor, then that is totally different and the non-interlaced pattern would be best.

So, in short, whether to use interlaced or non-interlaced depends on the display you intend to use. If you are going to watch it on an interlaced display, then use the standard interlaced pulldown patterns. That's what they're for. If you are going to watch on a non-interlaced display like a computer monitor, then use the non-interlaced pulldown patten because it will look better on a progressive display. The only speed where there is no difference between interlaced or non-interlaced is at 15 or 30fps because the film frames are evenly spread across all the fields (one film frame across 4 fields or 2 fields, respectively).

Contact me off list if you need any assistance.

Roger

[Rick Palidwor]

Thanks for the detailed responses.
Rick

[drsanchez]

Of course video runs at 30 fps, so the Workprinter file need to be altered in Permier or Final Cut Pro.

Surely there's other software that can alter speed?

[brightlight]

Of course video runs at 30 fps, so the Workprinter file need to be altered in Permier or Final Cut Pro.

Surely there's other software that can alter speed?

Well, sure. Those are just examples of programs I've used myself.

[Uppsala BildTeknik]

So, in short, whether to use interlaced or non-interlaced depends on the display you intend to use. If you are going to watch it on an interlaced display, then use the standard interlaced pulldown patterns. That's what they're for. If you are going to watch on a non-interlaced display like a computer monitor, then use the non-interlaced pulldown patten because it will look better on a progressive display.

I agree, but I feel the need to comment regarding all new TVs. They are flatscreen (those "fat" TVs cannot even be found in stores anymore, at least not here in Sweden).

When using a flatscreen TV you are not using a interlaced monitor, so the interlaced pulldown patterns are soon to be a thing of the past (or they pretty much already are).

[MIKI-814]

So I understand by your comments that the PAL system with 25 frames has an advantage for film shot at 24fps?

[Uppsala BildTeknik]

So I understand by your comments that the PAL system with 25 frames has an advantage for film shot at 24fps?

Yes.

[MovieStuff]

So, in short, whether to use interlaced or non-interlaced depends on the display you intend to use. If you are going to watch it on an interlaced display, then use the standard interlaced pulldown patterns. That's what they're for. If you are going to watch on a non-interlaced display like a computer monitor, then use the non-interlaced pulldown patten because it will look better on a progressive display.

I agree, but I feel the need to comment regarding all new TVs. They are flatscreen (those "fat" TVs cannot even be found in stores anymore, at least not here in Sweden).

When using a flatscreen TV you are not using a interlaced monitor, so the interlaced pulldown patterns are soon to be a thing of the past (or they pretty much already are).

Actually, flat screen TVs show both interlaced and progressive scan video. If they didn't, then raw interlaced video would look progressive due to forced de-interlaced display or would look weird due to progressive display of interlaced footage like on a computer monitor but neither is the case. The reason I previously used the example of a CRT type television is because it can show only interlaced footage, even when it is displaying progressive material, so it is silly not to take advantage of the interlacing for smoother playback of telecined material. But flat screens can show both interlaced and progressive and always will or, at least, we better hope so. Otherwise over half a century of interlaced archival news footage will lose half its resolution due to forced de-interlacing so that it can be seen on a progressive-only display. Also, the use of progressive only frames with no pulldown pattern is only beneficial if you shot at 24/25fps and display on PAL or at 25fps and display on NTSC at 24fps via a progressive medium like a DVD, where you can use pure 25p or 24p display modes. There is no pure 18fps or 16fps progressive display modes for DVDs. So a DVD that has film running at anything other than 24/25fps will need an interlaced pulldown pattern for the best motion characteristics. Any modern flat screen television can accomodate both interlaced and non-interlaced material.

Roger

[Uppsala BildTeknik]

Any modern flat screen television can accomodate both interlaced and non-interlaced material.

Roger

Yes, they can. But I thought they did so by de-interlacing when needed?
Are you sure they actually show the interlace fields "one at a time", just like CRT?

[MovieStuff]

Any modern flat screen television can accomodate both interlaced and non-interlaced material.

Roger

Yes, they can. But I thought they did so by de-interlacing when needed?
Are you sure they actually show the interlace fields "one at a time", just like CRT?

I have a couple of el-cheapo table top flat screens that don't and live interlaced video looks odd, like when you watch a movie in the theater and it has interlaced video transferred to film. But all my "real" HD monitors display the typical "live" look of interlaced video, just like a CRT, and are listed as 1080i monitors, which would be unnecessary if they weren't capable of interlaced display. There is the same visible difference on them when watching interlaced video as opposed to progressive scan video, just like watching the news on a CRT type of television. More to the point, watching interlaced pulldown telecined footage is much smoother on these monitors than when using non-interlaced pulldown patterns, so the advantage of using interlaced pulldown is still visibily there. But the el-cheap flatscreens look like crap, regardless.

Roger

[Uppsala BildTeknik]

Hmmm, I still have my doubts... I believe all flatscreens are progressive, in that case a non-interlaced pulldown and viewing the film without any de-interlacing should give a better image quality.

Is it really possible that the interlaced pulldown looks smoother after de-interlacing than a non-interlaced pulldown does without de-interlacing (on the same high quality TV)? I hope that made sense...

All flat panel TVs, whether plasma or LCD, are inherently progressive.
1080 line transmissions are interlaced to save bandwidth, a technique used since the very earliest days of electronic television.
The TV (or the receiving box) has to de-interlace the picture at some point.
Whether this causes a degradation or not is a bit of a moot point, as the de-interlacing process cannot be avoided.

The video processors built into most HDTVs lack the processing power to deinterlace high-definition video well, which is why some AV enthusiasts are willing to spend £1000 or more on a high quality external video processor.

With a 1080i source the difference between screens will be down to the electronics in the screen. Converting a 1080i picture to 1080p is a non trivial task and external boxes capable of doing this well start over £1,000.

But if you are comparing a standard screen that is 1080i and one that can take 1080p there is unlikely to be much difference as both efectively have to traslate the image to a progresive format for display (from the 1080i source).

I did a quick googling just to get some references for my flatscreen de-interlacing ideas. All above quotes are from: http://www.digitalspy.co.uk/forums/show ... p?t=575615