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25 fps or 29.97fps

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greg howell
25 fps or 29.97fps
on Jul 30, 2013 at 8:09:04 pm

Hi,

Am i right in thinking theres no point decreasing the frame rate if its going online? if its being put on vimeo, then PAL and NTSC does not come into it. correct? why would someone upload as 25 fps to vimeo instead of 29.97?

thanks


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Cassius Marques
Re: 25 fps or 29.97fps
on Jul 30, 2013 at 9:19:06 pm

Well since we're going online, theres no point of it being 29.97 (30 drop frame).

People go for 25fps or 24fps for a bunch of reasons. Its less data, saves up on render times, and some say is because the look and feel of film.

Would your audience be able to tell the difference? Is your work entirely digital or you've got some footage? I'd say theres little point in converting if you don't need to (from 30 to 25) and theres also little point in doing 5 extra frames for close to nothing.


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Tudor "Ted" Jelescu
Re: 25 fps or 29.97fps
on Jul 31, 2013 at 6:50:42 am

If you have a video with lots of movement, especially high speed graphics with movement, you want the higher frame rate because it allows for a smoother playback.

Tudor "Ted" Jelescu
Senior VFX Artist


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Walter Soyka
Re: 25 fps or 29.97fps
on Jul 31, 2013 at 11:20:59 am

[greg howell] "Am i right in thinking theres no point decreasing the frame rate if its going online? if its being put on vimeo, then PAL and NTSC does not come into it. correct? why would someone upload as 25 fps to vimeo instead of 29.97?"

To be a bit pedantic, PAL and NTSC define analog signals for standard definition video, of which the standards' raster sizes, colorimetries, and frame rates are only a part. Talking about PAL and NTSC in HD is meaningless; only the frame rate of HD differs across PAL/NTSC regions.

If your monitor's refresh rate is not evenly divisible by the source's frame rate, it will exhibit a bit of a stroboscopic effect where frames are dropped or repeated.

For example, you can't evenly divide 25 frames of European video into 60 Hz (the refresh rate of many monitors in the US), so you get a bit of a cadence to the playback where frames are repeated. Assuming each frame will be duplicated or shown twice to bring 25 fps up to 50 frames per second for display, we still need 10 more frames to display to get to 60 Hz. 25 is not divisible by 10, so some frames (but not all!) will have to be shown three times for display while the rest are shown twice.

For that reason, it still may be meaningful to consider the frame rate for your primary audience. Some viewers will be bothered; others won't notice at all, but there will be a technical flaw.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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greg howell
Re: 25 fps or 29.97fps
on Jul 31, 2013 at 12:03:13 pm

ok, so assuming my audience are all using computers most of which are in the uk, will it be ok to leave at 29.97?


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greg howell
Re: 25 fps or 29.97fps
on Jul 31, 2013 at 12:03:57 pm

..i'm also happy to sacrifice frame quality and file size


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Tero Ahlfors
Re: 25 fps or 29.97fps
on Jul 31, 2013 at 1:20:18 pm

You really can't control the viewers monitor refresh rate. If I'd be making anything for UK or Europe I'd use 25fps because nobody over here uses 29,97fps.


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greg howell
Re: 25 fps or 29.97fps
on Jul 31, 2013 at 5:14:15 pm

see this is what confusing me. if you were ok with it being a larger file size with each frame being slightly lower in quality, why wouldnt you use 29.97 or 30 fps? - you say that if people in the uk were watching it, then you should use a lower frame rate, but why?; they will be veiwing it through a computer monitor, not a tv. so pal doesnt apply, does it?

thanks,


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Dave LaRonde
Re: 25 fps or 29.97fps
on Jul 31, 2013 at 5:37:05 pm

I don't know if the frame rate for internet-only video is a big deal beyond the already-discussed motion concerns.

I'm sure I've watched Vimeo stuff done in Europe, and it looks fine here in the USA. So I bet you'll be good, too.

Dave LaRonde
Former Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Cassius Marques
Re: 25 fps or 29.97fps
on Jul 31, 2013 at 8:01:53 pm

Why do you say frames will be lower in quality?


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Walter Soyka
Re: 25 fps or 29.97fps
on Aug 1, 2013 at 1:55:05 am

[greg howell] "you say that if people in the uk were watching it, then you should use a lower frame rate, but why?; they will be veiwing it through a computer monitor, not a tv. so pal doesnt apply, does it?"

It's not an issue of NTSC and PAL. European power cycles at 50 Hz, and computer monitors refresh at 50 Hz (50 fps). 25 fps material will be smooth because it's an even divisor of 50; 30 fps material will stutter just a little because it's not an even divisor of 50.

It will work -- that is, the video will display -- but it will exhibit this technical error as a visible flaw. Whether your audience cares or even notices is a separate question.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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greg howell
Re: 25 fps or 29.97fps
on Aug 1, 2013 at 7:55:35 am

Now i understand walter, thanks!


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Matthew Keane
Re: 25 fps or 29.97fps
on Aug 1, 2013 at 11:37:54 am

Walter, while it's true that power in Europe cycles at 50Hz, most computer monitors here run at 60Hz, probably because this seems to be the default for most graphics cards. Getting a full chain of 50Hz playback and display (for example, when mixing live video and projected backdrops in Watchout) is not always as simple as one might hope it would be!

Matthew Keane

Freelancer based in Paris, France
- Motion Graphics, Video Editing & Effects, Watchout Programming & Live Operation.


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Walter Soyka
Re: 25 fps or 29.97fps
on Aug 1, 2013 at 12:36:57 pm

[Matthew Keane] "Walter, while it's true that power in Europe cycles at 50Hz, most computer monitors here run at 60Hz, probably because this seems to be the default for most graphics cards. Getting a full chain of 50Hz playback and display (for example, when mixing live video and projected backdrops in Watchout) is not always as simple as one might hope it would be!"

I stand corrected. Everything I've produced for Europe has actually been for WATCHOUT systems or other systems interfacing with video, where I guess we had control over the refresh rate via EDID management.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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