Best Telecine for Vision2 Negative shot at 18fps?

[SKJ]

I'm looking for advice on a high quality place that can do a direct-to-drive transfer of Vision2 Negative at 18 fps.

I sent some rolls to a respected place, and there's interlacing artefacts that entirely unacceptable to me. They are saying that the problem is "caused by the pulldown needed to create 29.97 NTSC video from an 18fps source, however there isn't much I can do about that. You may have some luck using Cinema tools to remove the pull down, I know people use it to remove pulldown from 24fps material, however I'm unsure if it can be used on 18fps material. I believe the pulldown sequence for 18fps material is 3:3:4 as apposed to the 2:3 pulldown for 24fps material."

I then talked to Toni Treadway, at Brodsky & Treadway, who have done all of my reversal transfers (and don't handle negative), to ask about why my reversal transfers have never had this problem, and she said she couldn't explain what other people were doing, but of course it IS possible to have smooth transfers of material shot at 18fps, but that most places are not set up for it.

Attached is a still from the transfer:


Anyone have any advice?

Thanks!

Stephen Kent Jusick

[Uppsala BildTeknik]

I´m not sure it is a problem. It depends on what you plan to do with the footage, if you are going to show them in a interlaced TV (or de-interlace the footage) then it isn´t a problem.

What you have got is that the missing frames (to get to the correct framerate) are built up by mixing the frames that exist in order to give as smooth playback as possible, on interlaced monitors, this is what you get. If you create the missing frames by mixing interlace fields.

If they however would have created the missing frames by duplicating frames, you would not have this effect. The playback would be a tiny bit more jerky on interlaced monitors, and on non-interlaced monitors you could playback the file without the need for de-interlacing.

Next time tell them (or ask them before sending them your footage) if they can create the pulldown with progressive images, by repeating frames instead of mixing interlace fields.

[SKJ]

Thanks for your analysis of what is happening. I'll be sure to poll future post houses on exactly what they do before sending work their way.

As for whether it's a problem or not: It IS a problem because the footage now looks more like video, than film, whether its played as a file, or burned to a DVD or tape. Analog transfers look much smoother to me, so this is a step back, as far as I'm concerned.

SKJ

[Uppsala BildTeknik]

t IS a problem because the footage now looks more like video, than film, whether its played as a file, or burned to a DVD or tape.

Your interlaced TV should not show any lines. And your flatscreen TV shouls de-interlace the footage, again, without any of the interlace fields showing.

If you can see the lines on your computer then the software is not de-interlacing it properly.

A DVD player connected to whatever kind of TV should not show these lines, they should either be invisible or be de-interlaced without any need for additional options/input from the one throwing the disc in the player.

[Andreas Wideroe]

Disclaimer: First I'd like to mention that I work with telecines every day and this subject comes up from time to time in my facility aswell. I'm not a technical genious nor an expert, but this is how I understand things. Please correct me if I'm wrong.

To me it looks like you have transferred your films to SD 525i video (perhaps to a Blackmagic or other v210 codec?).

I understand you're in the States and NTSC world. This image looks perfectly normal to me. It looks like a normal SD 525i@60hz video stillframe. If you pull out a single stillframe from a transfer like that it will look like this. Remember SD is interlaced by definition. There is no such thing as progressive in the SD specifications (that I've been told by one of the EBU engineers). Infact all SD TELECINE (film recorded/transferred to video while running in realtime) creates international standardized SD interlaced video and there's a long and interesting history why.

Ever since technology changed into computers, fast CPUs, large screens, huge storage etc people want full whole uncompressed frames from their transferes and I understand that. It's only today when we work so much with computers and flatscreens that interlaced video has become a problem for many of us.

Only scanners can scan film and create a "progressive" filmframe on a computer. To create motion these stillframes are put into sequences with X frames per second. This is progressive video Ie. 24p. This is what you're looking for as I understand. I guess your other facility use a Workprinter or similare device which "scans" the film (with a videocamera) and grabs a stillframe from the film (a whole frame) and put these stillframes into sequence to create a videofile. This is why you see a difference.

As Kent mentions your TV screen shold de-interlace the film and your computerplayer should too, but this will not always be the case - especially if your film has been captured using a Blackmagic or other uncompressed codec. Try playing the file back in VLC player and deinterlace it while playing. Looks great, doesn't it?

What you should do in the future is to either look for a facility that can do a DATASCAN of your footage or find someone who has a Spirit (or similare) with a Super8 gate. This should be able to make true progessive scans of your films. However, beware that the price will be much much higher than for an SD transfer. A spirit alone cost somewhere around $ 2 million and that's only the machine. You need so much more to be up and running. ;-) Your othere choice is the stick to SD and do the best out of it. Still, an uncompressed 10bit scan of your Super8 film is better than Digibeta which is the broadcast standard.

As for the 18fps to 29.97fps conversion. This will always be a problem. A telecine will create the missing ~12frames from the existing 18frames and this is done the way Kent describes. Either from lines of the existing frames and with a pattern or you can take whole frames and add them in a specific pattern. The latter one can create funny motion.

My suggestion is always shoot your film in 24fps. Then it can easily be transferred to 24p if you find a company who can deliver that.

Anyway, I think you should be able to get some good result by using a deinterlacing software or filter on your films.

Best of luck!

Andreas

[Uppsala BildTeknik]

There is no such thing as progressive in the SD specifications

What I meant when I wrote "progressive images" was that they would repeat the full images instead of mix interlace fields. That would kill the whole problem with interlace fields showing up anywhere on computers and/or flatscreen monitors.

My suggestion is always shoot your film in 24fps.

That is definetly the best thing to do.