CRT TV's modified for movie use

[lnx64]

I heard a rumor from someone who worked in movie production in the 90's, that they regularly had CRT TV's modified to have a refresh rate that didn't flicker to a film camera shooting at 24 frames per second, and it required a special source to even feed it video.

I have heard this a couple times in my life, but never really any proof that this was "a thing".

Has anyone heard of these CRT's modified for syncing to a 24fps film camera shutter to reduce flicker?

I do have a movie camera that films in 24fps, but I am of course able to film at 24fps, if I use a 1/60th shutter (even or odd only frames), or 1/30th shutter (both frames). But I can't imagine hollywood modifying TV's for this if you can simply adjust the shutter of the camera.

[Electronic M]

I've heard of those modified sets too. I believe they did exist. The film industry was totally married to 24fps film and cameras and would not change their equipment to accommodate TV....In fact before video tape TV stations would save shows on film (kinescope)...24fps film.

It would not be hard to change the sweep rates of TVs to 24 fields per sec and sync to the cameras....Also in the late 50's early 60's some of the larger film studios started buying VTRs, TV cameras, and monitors that I believe were set up for 24fps operation....These would be run parallel to the film chain so the director could immediately playback a scene just filmed and decide if it was done right without having to wait for the film to develop.

[Chip Chester]

Just look in the end credits for the name of companies and individuals that supplied 24-frame playback equipment for the film. Anything that's TV-centric, or has even incidental TV and computer footage will utilize them.

Playback Technologies, Compuhire and more are listed, (details on IMDBpro.) Specific methodologies probably available on Wiki.

The goal of the synchronized system is for a complete frame (usually two interlaced fields) to be visible (via persistence) on the CRT at the exact moment the camera exposes the film... instead of half- or third-frame images. Rolling of the picture is controlled, too.

Chip

[TUD1]

I once watched a movie that had a bunch of CRT sets that appeared to be working, and in the movie, the 15,750 kHz was very loud. Almost like they were trying to make it annoying.

[David Roper]

Harry Poster was a prime source of 24 fps modified sets. For many years that was an additional option to "as found" or "empty prop" offered on his website. It was very much "a thing".

[lnx64]

Interesting.

I have a Sencore video generator that does generate a 24fps signal (though it's technically 48Hz). Only my PVM will sync to it.. My Samsung in my signature does try to sync to it if I adjust the vertical hold, but it's near the extreme edge of the knob.

[Olorin67]

the frame rate difference also created complications when films were shown on TV. Tv stations used a set up called a "Film Chain" with a special projector that would repeat a frame occasionaly to keep it in sync. You can see one in operation at the Pavek museum in Minneapolis. I think they keep it in the warehouse, but will fire it up if your'e interested. I think i read that in Europe they would just run the film a tad fast to match the 25 FPS rate of european tvs, so the sound would be a little sped up too.