8mm Forum: Film speed, physical inspection.

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Posted by Mark Davies (Member # 6249) on February 28, 2018, 08:48 AM:

From just examining a film by eye (that is, not running it through a projector), can you identify what speed it should be run at.

My initial thoughts are no.

Which would bring me onto a second question. If one runs the film, a silent film (taking away the ability to identify the speed by slow or fast audio), is it always possible to identify the correct speed? Thanks

Kind Regards Mark.

Posted by Steve Klare (Member # 12) on February 28, 2018, 09:28 AM:

Basically anything commercial from about the mid-twenties on really should be 24 FPS, even the silents from that era. If you have something from the 'teens or earlier you can legitimately do 18.

That much being said: I often run twenties silents at 18 because the projector is quieter. I do this at the risk of the pace of the story feeling a little bit lazy, but without audio to cover the machinery sounds...

Home movies will almost always be 18.

Posted by Mathew James (Member # 4581) on February 28, 2018, 09:41 AM:

I picked up a weird anomaly recently..at least weird to me because I hadn't any others before in my collection...

Charlie Chaplin Blackhawk 400' Super 8 Sound code 875 The Tramp
It is my only Super 8 sound I own that runs at 18. In fact, I actually love it because I get a bit more film time...

I cannot tell by looking...

Posted by Steve Klare (Member # 12) on February 28, 2018, 10:01 AM:

Matt?

Did Blackhawk put some kind of notice in the packaging so the customer knows about this?

(I've heard of these, but never seen one in person.)

Posted by Ty Reynolds (Member # 5117) on February 28, 2018, 10:16 AM:

Chaplin, among others, shot some of his films at 18, to be projected at 24. He did this even into the sound era, in certain scenes of City Lights and Modern Times. I wonder if that's the case with yours.

Posted by Mathew James (Member # 4581) on February 28, 2018, 10:38 AM:

@steve, If there was a notice originally, it was removed from inside box.
However, the spine sticker says 875, so those who know the blackhawk codes could know potentially by seeing the spine.
I wonder if it specified in the catalogue?
880=s8s
860=s8silent
875=s8s_18
It was a pleasant surprise for me. I bought 4 mint chaplins from someone here in Canada and one was the 875.
I want more!!!

Posted by Brian Fretwell (Member # 4302) on February 28, 2018, 10:52 AM:

The only thing that could be a guide is gravity. If a car in the film seems to bounce on its springs at an unnatural rate (slow or fast) then the film is not being projected at the same frame rate it was filmed at. This is most obvious when chases have been under-cranked and sped up to show a more exciting view. Small changes are more difficult to spot, though.

Posted by Dominique De Bast (Member # 3798) on February 28, 2018, 11:10 AM:

I have some silent films with a music score that must be projected at 18fps. One of the film (not Blackhawk) has a specific instruction about the speed. Some (Chaplin) silent films with an optical soundtrack are also at 18fps (but for those I haven't the original boxes).

Posted by Steve Klare (Member # 12) on February 28, 2018, 11:24 AM:

Gravity is the best guide: unless they are supposed to be on another planet it is very telling.

Walking is also very good: 24 FPS walking becomes kind of a leisurely strut at 18. 18 FPS walking at 24 looks a little bit caffeinated!

Posted by Chip Gelmini (Member # 44) on February 28, 2018, 11:58 AM:

Mechanically speaking you can purchase a strobe light that can be set to 24 flashes per second and aim it at the shutter blade with the gear box open. If the machine is up to speed, the shutter blade will appear to be frozen still position. However if the pattern of the shutter blade seems to turn either direction during this test, then it could be going to slow or too fast.

I saw this done with a 35mm machine and it is a most interesting test to do. Even though I might not be answering the question that was asked....

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