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24 fps vs 18 fps


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#1 tom lombard

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Posted 10 December 2017 - 02:49 PM

Pretty sure I've got a handle on this but it never hurts to double check.  Am shooting with a 16mm Bolex and am considering shooting at 18 fps rather than 24 just to make a 100' roll last longer.  It will be telecined & edited in Resolve so I just pay attention to bring it in at 18.  Sound will be recorded externally with tracks (dialog, score, foley) laid over top individually.  There won't be any rapid action or real quick dialog so the difference in frame rate shouldn't be noticeable in the end.  Do I have that correct?  This will also expose the frame a bit longer so & should be able to get more depth of field.  This (8 minute short) will be shot outdoors in full sun or partial shade (park setting) with D50.  I was planning on over exposing a bit (maybe set camera & light meter at 40) but think it won't be desirable at 18.  I think that the deciding factor on that may be what stops look best thru the lenses I'll be using (Nikon Series E 35, 50, 100, and 75-150 zoom) and set ASA accordingly with desired depth of field in mind.  Any input appreciated.  Thanks, Tom


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#2 Landon D. Parks

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Posted 10 December 2017 - 02:57 PM

18fps shot at 18fps and played back at 18fps will not experience any 'fast motion' effects, but it will change the characteristics of the moving image. If you want to see what 18fps looks like, just watch some old 8mm/super8mm stuff on Youtube. It definitely has a different motion feel to it, even if ever so slightly. 

 

Sample:

 

https://youtu.be/jfw...t=RDdx76mdu5d5w


Edited by Landon D. Parks, 10 December 2017 - 03:05 PM.

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#3 tom lombard

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Posted 10 December 2017 - 03:02 PM

That actually would be a good thing as I'm going for subdued & dreamlike.


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#4 Phil Connolly

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Posted 18 December 2017 - 10:51 AM

One thing to note might be issues with screenings. Although you could master to an 18fps digital file - to make DVD's, screen on TV's or DCP's for cinema etc... A more standard framerate of 24 or 25 fps may be needed.

 

I've got a few 18fps bits on my showreel that I had to convert to 25fps , so I could intercut it with everything else. This does affect the look ,as well and kind of introduces a smeary artefact on top as it interpolates more frames. You might like it, but its worth noting its another thing to deal with along side the jerky motion you get with 18fps.

 

I quiet like 18fps for the dreamy quality and the stock savings and extra exposure is a bonus. However I thin 18fps might be a bit slow for dialogue - might make lip sync look a bit loose. Its something I'd test before shooting lots. 

 

You might want to investigate (if you haven't already) Wong Kar Wai's use of step printing to work at slower frame rates. For the right application that could look great and save stock, e.g shooting at either 6,8 or 12fps and printing the fame multiple times - so the action runs at normal speed at 24fps projection but the motion is blurry and juddery

 


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#5 timHealy

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Posted 20 December 2017 - 06:03 PM

Lots of step printing at lower frame rates by Robert Richardson in JFK. They also experimented with lots of film stocks and formats.

 

Best

 

Tim


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#6 Landon D. Parks

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Posted 20 December 2017 - 08:32 PM

Another thing to consider, DCP packages are 24fps, not 18fps. This means any theatrical exhibition will need a 24fps file. This could also affect some higher-tier film festivals - the ones that themselves require a DCP for screening. 


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#7 Gregg MacPherson

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Posted 20 December 2017 - 10:25 PM

I don't think 18fps feels subdued and dreamlike. More...edgy, and agitated...If you are shooting with a Bolex you can control the motion blur with the shutter...


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#8 Tim Smyth

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Posted 22 January 2018 - 05:03 PM

I did not know 16mm cams shot at 18fps, I always thought it was 16fps. I thought it was the Super 8 cams that adopted the 18fps as a norm, even for sound. More than likely in the transfer they will fix it to run at 24fps, by doubling up frames, as opposed to transferring the footage at 24fps.


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#9 George Ebersole

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Posted 22 January 2018 - 07:46 PM

18fps shot at 18fps and played back at 18fps will not experience any 'fast motion' effects, but it will change the characteristics of the moving image. If you want to see what 18fps looks like, just watch some old 8mm/super8mm stuff on Youtube. It definitely has a different motion feel to it, even if ever so slightly. 

 

Sample:

 

https://youtu.be/jfw...t=RDdx76mdu5d5w

 

 

Not to get too off topic, but that's really cool footage.  If it weren't for the SUVs in the footage I could have sworn that was California right before the bicentennial when I was a kid.  


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Broadcast Solutions Inc

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Visual Products

Wooden Camera

Rig Wheels Passport