first really commercial/corporate job with FCPX

[Franz Bieberkopf]

[Richard Herd] “These are cool website”

Richard,

Thanks – I think I’ve visited those sites before.

Thing is, they are perpetuating vagaries in the “3:2 pulldown” language – they discuss in good detail the 3:2 field cadences and why it is necessary and it’s implications, but they don’t discuss the speed difference (slow-down) part of the process.

“The lurkers guess that it’s called 3:2 pulldown because the pattern of fields you get contains sequences of 3 fields followed by 2. Or perhaps it’s called that because 3 of the 5 video frames do not end up coinciding with the start of a film frame and 2 do.”

Franz.

[Jeremy Garchow]

[Andrew Kimery] “I really hope that they shot both 24p and 60p so the 60p could be used for slow motion.”

Yes. And the 25 was shot for just a bit of slow motion. But just a bit!

🙂

[Jacob Brown]

haha funny. 25 was i think because it came from europe or something. 60 was indeed for slo-mo.

of course all problems avoidable with proper planning. but sometimes you’re young and hungry and take a job at very last minute and it all just sort of happens without any planning.

anyway, glad everyone had fun replying to this one at least!

[Richard Herd]

[Franz Bieberkopf] “they are perpetuating vagaries in the “3:2 pulldown” language”

Where are the vagaries originating? We can agree it isn’t reality itself, right; it just is. So in some way SMPTE and lurker (one of the QuickTime developers before AVFoundation) had to make decisions. It’s always bothered me that Legacy reports 23.98 when 24M should be 23.976 as AE and PP and X do (don’t know Avid; we broke up in 2003). I don’t know if they are calculating 23.976 and rounding up on the browser display, or if it really is 23.98 having rounded up somewhere else. What say ye?

[Franz Bieberkopf]

[Richard Herd] “Where are the vagaries originating?”

Richard,

I think much is to be blamed on the ad hoc development of video tape in the first instance, and film to video in the second. In essence, it seems to me it was kind of an oral culture in spite of the highly technical engineering challenges.

And 24p in 29.97 comes to us from a very specific use case (film in NTSC video) – so principals that were developed there were never really thought of in broader terms of frame rate conversions until recently.

[Richard Herd] ” I don’t know if they are calculating 23.976 and rounding up on the browser display, …”

Allan Tepper just posted an excellent (if somewhat wordy) listing of such issues on PVC:

https://provideocoalition.com/atepper/story/video-framerates-and-the-tower-of-babel-a-translation-guide

Franz.

[Jeremy Garchow]

[Richard Herd] “What say ye?”

I don’t know about ye, but I’d say 24000/1001 is correct enough.

[Jeremy Garchow]

[Franz Bieberkopf] “Allan Tepper just posted an excellent (if somewhat wordy) listing of such issues on PVC:

https://provideocoalition.com/atepper/story/video-framerates-and-the-tower-o...
“

Well that’s rather serendipitous.

[Franz Bieberkopf]

[Jeremy Garchow] “Well that’s rather serendipitous.”

I actually question one of his statements:

“I am the first to admit that even numbers like 23.976 and 29.97 are not exact either. They are actually simplifications of a more complex number, which would be the result of 30 ÷ 1/1.001 or 24 ÷ 1/1.001, whose results are very long and not feasible to be used in common speech or even writing.”

I actually think that 23.976 and 29.97 are precise representations of whole number frame rates slowed down by 1/1000 – that is, I think 1/1000 is the correct fraction, not 1/1001 as he states.

?

Franz.

Edit: Wiki tells me this:

… designers adjusted the original 60 Hz field rate down by a factor of 1.001 (0.1%), to approximately 59.94 fields per second. (which still seems contradictory to me)

… and then this:

Dividing (4,500,000 / 286) lines per second by 262.5 lines per field gives approximately 59.94 fields per second.

… which seems more precise and yields 59.94005994005994

https://en.wikipedia.org/wiki/NTSC#Lines_and_refresh_rate

Question answered, doubt relieved, carry on.

[Jeremy Garchow]

[Franz Bieberkopf] “I actually think that 23.976 and 29.97 are precise representations of whole number frame rates slowed down by 1/1000 – that is, I think 1/1000 is the correct fraction, not 1/1001 as he states.”

That’s because it isn’t exactly 1000th of a second slower, it’s actually a repeating fraction slower .001001001001.., (or 1/1001).

Jeremy

[Jeremy Garchow]

To add to that, 23.976 fps is actually 23.9760239760239… fps