Why still use 23.976 and 29.97?

I'm still learning... but I know unless a project is going to play in the theaters... I should record and use 23.976 instead of 24fps when given the choice.

I know I should, because resounding I've been told I should. But I guess I don't really understand why.

Using the fraction frame rates has more to do with NTSC monitors doesn't it? And since the world is moving away from that is it still necessary to use 29.97 or 23.976?

Or does it have more to do with broadcast? And if that's the case, what about personal projects that I shoot and only plan to watch on my computer or DVD player? Or does DVD require the fraction frame rates too?

I've been reading up on the subject and asking questions, but maybe because I started learning about frame rates while there was a choice between 24p and 23.976 and 30p and 29.97, that is why I'm having such a hard time with it. To me life would be so much easier if there was just one to use (like before I was editing and it was all 29.97) But if it seems we are headed towards 30p only in the future.... why still use 29.97 (or 23.976)for new projects?

Thanks for any help understanding this... I'd like to get if sorted out once and for all!

[Robert Houllahan] " so legacy SD material can be up-rezzed to 1080i without cadence issues"

I guess that makes sense. Thanks for the answer.

Another question in the same area:

Over the weekend I recorded some stuff off my computer using FRAPS. I had the choice of 30fps and 29.97. I chose 30fps.

The problem I had was when I put in in FCP7 I could not play it to my grading monitor through my decklink card. In the Audio and Video settings I could not find a Blackmagic 1080p 30fps (or 60fps) setting.

Is there no 1080p 30fps or am I missing something?

Thanks

[Doug Beal] "your grading monitor wants to see an NTSC signal"

I've always thought NTSC monitors are CRT. My grading monitor is LCD but it is hooked to the computer using a SDI > decklink card > HD Link Pro > display port cable and IN.

Does that connection make it NTSC?

The HD link might be the weak link.

I can always hook up my grading monitor to my graphics card if I want to do FCP editing with 30p I suppose.

This does lead to my ultimate question:

If I'm recording stuff from computer using FRAPS that I want to keep for nostalgic purposes - for 10,20,30 years... etc. Should I do it in 30p or 29.97?

I'd watch it on my Computer and DVDs... although DVDs probably won't last that long.

I'm just wondering if I do 29.97 if that might cause viewing problems in the years ahead?

Any suggestions?

Thanks :)

I'm happy to be in europe for that :-)

réalisateur, scénariste, monteur, étalonneur
http://www.robinerard.ch

That's why, unless there are mitigati circumstances, I always recommend shooting 23.98. 23.98can easily be converted to 24 (and therefore 25 & 50i using pull down) and 29.97. It's the best compromise for a "filmic" look.

However for using fraps, 23.98 might not actually capture the feel of what you're doing. and you might need to go 720p60 for some video games.

30p though should be easy to covert to 2997 in compressor, just use the "set so frames play at 2997" setting.

And the reason that NTSC is 29.97 and pal is 25 is because the US' electricity grid is a voltage thing. Original analogue tv's had to run at the fraction of the timing that your voltage did. And because ac power in the US is not quite 120hz, hence 5994i, 2997, and a much later hack to get film's 24fps to 29.97, 23.98... Europe design PAL much later and was able to create a higher resolution system.

Joseph Mastantuono
http://www.goodpost.net
Color Grading & Post Production Consulting

[Joseph Mastantuono] "30p though should be easy to covert to 2997 in compressor"

I realized this was on question I had not asked.

Is there any "damage" done when converting 30fps to 29.97? Or 29.97 to 30.00?

I did some tests and I could not see or hear any difference. I don't have enough experience to know if there may be any problems here though.

Consider external audio sync issues if you are in fact converting from "whole frame" 30.000 fps to 29.97.

I know this from long and hard-won lessons transferring 24 fps film (the kind with sprockets) to 2997 with double system sound. In fact it is this frame rate that is the "pull down" that people refer to as "3:2 pulldown". (Its not the "pulldown" that gets removed, its the redundant fields).

Also beware that some consumer solutions obfuscate the frame rate nomenclature in a vain and misguided attempt to simplify things for an otherwise oblivious market. For example, Final Cut still refers to 23.98 as "24". It makes it confusing for those of us who actually understand these things, and need to know what the exact frame rate is. So although you may indeed be shooting at 30.000 fps, there is still the possibility that that is in name only, and would be a mightily weird choice and a departure from over a half a century of an established format. It does disqualify your project from a majority of transmission methods.

jPo

You mean "Old Ben"? Ben Kenobi?

[Dean Manion] " 3.58 mHz color subcarrier had to jibe mathmatically with the number of total scan lines per second "

Also has to be a multiple of the horizontal scanning frequency (15.75 KHz) to come out to colour-framed subcarrier phase on odd/even fields. This is compounded slightly by the existence of half-lines in analog NTSC. An active NTSC field is 262.5 lines, so each one starts 90 degrees out of phase with the preceding field. This used to be very important in composite baseband editing, but the advent of component processing (Betacam) changed the parameters. Its why there is a 2F/4F switch on the front panel of those decks that were also expected to function in the analog NTSC baseband world.

The 15.75 KHz scan is the source of the high-pitched squeal that CRTs used to produce as a result of the flyback transformer that generated the sawtooth voltage that sprayed the beam across the faceplate.

jPo

You mean "Old Ben"? Ben Kenobi?