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choppy picture 8mm -> DV


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#1 martin dimitrov

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Posted 16 October 2006 - 02:59 PM

To all cinematographic gurus out there, I would appreciate some guidance

is there a way that a regular 8mm film shot at 16 fps can NOT look choppy when transferred to DV, NTSC 29.97 fps?

I have already read a few posts on this forum where folks inquire about the "smoothness" of a video when an 8mm film is transferred into NTSC 29.97 fps. The responses as I read them are favourable but I guess this is a matter of perception. I recently had regular 8mm films from 1980 transferred to DV and when I play them on a computer, they seem choppy to me

I can describe one of the symptoms like this: There is the inevitable slight shaking when the camera is held by hand. When I preview these video files on a computer, that shaking seems like is doubled when compared to the films as projected on the wall and is very annoying.

Is this a result of the process known as "pull down" and is there more than one way to perform the pull down i.e. one way would result in a choppy picture whereas another way would be smoother

Thanks much
Martin
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#2 Bernhard Zitz

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Posted 27 October 2006 - 03:05 PM

I live in PAL-land, so i don't know much about ntsc, but I guess if you transfer it at 14.985fps (should be close enough to 16) there shouldn't be pull down issues. This would make two full video-frames for one full film-frame.

What frame-rate (on the telecinemachine) did you transfer it?

Computers (quicktimeplayer, dvd-player on computer etc..) usually can't display correctly interlaced stuff, either they de-interlace by displaying only one field(interpolate) or they show both fields at the same time (that's what the dvd-player on mac does) this gives this ugly horizontal lines...

Certain compression codecs do strange stuff with keyframes etc. this could result in choppy image... although this shouldn't be in DV

What happens if you play your DV-tapes on a regular TV-set or crt-monitor?
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#3 martin dimitrov

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Posted 31 October 2006 - 05:11 AM

I live in PAL-land, so i don't know much about ntsc, but I guess if you transfer it at 14.985fps (should be close enough to 16) there shouldn't be pull down issues. This would make two full video-frames for one full film-frame.

What frame-rate (on the telecinemachine) did you transfer it?

Computers (quicktimeplayer, dvd-player on computer etc..) usually can't display correctly interlaced stuff, either they de-interlace by displaying only one field(interpolate) or they show both fields at the same time (that's what the dvd-player on mac does) this gives this ugly horizontal lines...

Certain compression codecs do strange stuff with keyframes etc. this could result in choppy image... although this shouldn't be in DV

What happens if you play your DV-tapes on a regular TV-set or crt-monitor?


Thank you Bernhard
the films were transferred on equipment that does a "frame-by-frame" transfer so all the issues about synchronization and different frame rates are avoided automatically

If I transfer the AVI files onto a DV tape and play it on my TV, it looks the same way

What tools can I use to reveal how these AVIs were created? Any ideas on how I can perform the pull-down myself (I have the original AVIs)

Thanks much
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#4 Bernhard Zitz

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Posted 02 November 2006 - 06:47 AM

What tools can I use to reveal how these AVIs were created?


I'd ask the telecine-guy how he did it...
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#5 Albert Smith

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Posted 05 November 2006 - 01:04 AM

16fps is a very slow frame rate, its going to be choppy, as you are seeing less frames, with larger gaps in time between them, then if you shot at a higher frame rate. even 24fps is some what "choppy". there is really no way around this...maybe some frame blending techinques could be used but that might not be the best thing.
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