Legend

Question

Shoot 29.97i or convert for deliverable?

Forum|Forum|2 years ago
October 2, 2023
4 replies
1634 views

I have a proposed upcoming project under early discussions. It's for a non-profit, where the more likely destination is client web use. But, if possible, it would be pitched to public TV.

Local public uses NPB standards, everything in 29.97i drop-frame. Of course that's 59.94.

That would not be my primary choice to shoot in. But I know a workable practice has been shoot 24p, edit, then take to Ae and do 3:2 pull-down.

Is that still the best thing, other than shooting in interlaced?

This topic has been closed for replies.

R Neil HaugenAuthor

Legend

Thanks for those responding ... but perhaps I'd also like @Jarle Leirpoll , @Warren Heaton10841144 , and @Michael Grenadier to opine? I do like a range of experienced thoughts. The more the merrier ...

Everyone's mileage always varies ...

M

Michael Grenadier

Legend

Just finished a pbs cutdown. I was told to deliver 29.97, but the piece was mastered as 24p Gonna see if 24p will be accepted... I've mentioned this to the client, but as usual, radio silence. Not sure what the best way to add pulldown to make it 29.97... If I remember correctly not a simple process to get the best quality, bwdik...

Warren Heaton

Community Expert

Interesting.

I think at best "24p" is ambiguous as to frame rates (ie. used to refer to both 23.976fps and 24fps).

First I will note that the wikipedia page seems quite dated. (example: "Some 24p productions, especially those made only for NTSC TV and video distribution" ... using NTSC as a foundation misses a lot in 2023.) Premiere Pro (and other NLEs) are straddling a lot of standards, but some good references would be ATSC and DCI which encompass broadcast and theatrical in the U.S. and beyond.

It's true that I assumed 24fps is indicated by the "24p" formulation - which is presumptuous since he has only indicated progressive frames but not frame rate. But by such logic I must assume that "24p" does not communicate any frame rate information at all (or rather, only narrows it to either 23.976fps or 24fps).

It's also true that there's a lot of informal shorthand re: 24 vs 23.976 and 30 vs 29.97 frame rates ... but in a forum post about mastering and frame rate / format conversions, it's safe to assume that precision is necessary. (I don't see how you can make meaningful recommendations or decisions otherwise.) Thus my interpretation of Neil's post, your post and careful qualifer on Warren's (very useful) AE instructions.

I'll add that later formulations of formats (example: 1080p24, 1080p23.98) were clearer in communicating frame rates and also suggested an interpretation of the (I believe etymologically earlier) '24p' which I seem to have taken on. (In case it's unclear, 1080p24 unambiguously communicates 24fps).

"Neil, in his initial post clearly is talking about 23.976."

I did not interpret it that way - nor would I with any such correspondence. This was reinforced by his references to 29.97, 59.94, an to pull down (though again 'pull down' has been widely adopted in a sloppy way as well).

R.

Let's see.

When summarizing video settings, like 1080p24, its frame size which is followed by the scan method which is followed by the frame rate.

"p" stands for progressive scan; however, with modern displays that have a refresh rate rather than a scan rate this is a holdover from CRT displays.

"i" stands for interlaced scan.

p23.976 (also called p23.98 and p24) is a valid frame rate and can be pulled down to i29.97 or i30 which can be pulled up to p23.976 with full cadence. Cadence refers to the pattern used to convert whole frames to interlaced frames. There is no i23.976.

p24 is a valid frame rate and can be pulled down to i29.97 or i30 for finishing. It's not meant to be pulled up. There is no i24.

p25 is a valid frame rate. In the early days of digital video, it was popular for shooting video and then printing to film.

i25 (also called i50) is a valid frame rate. Using "25" favors frames and using "50" favors fields. It's usually associated it PAL and SECAM.

i29.97 (also called i59.94, i30, and i60, and once in a blue moon i29.976) is a valid frame rate. Ideally, it would just be called i29.97 with no rounding. It's likely drop frame timecode (dftc) but can be non-drop frame timecode (ndftc). It's usually associated with NTSC.

i30 (also called i60) is a valid frame rate. It is often non-drop frame. It's usually associated with NTSC.

The frame rate for NTSC and the frame rate for PAL/SECAM are both supported by ATSC.

p29.97 and p30 are valid frame rates, but these should be avoided if possible for source footage. They are better suited to being a result of deinterlaced i29.97 or i30 when exporting.

p47.952 (also called p47.96 and p48) is double p23.976. This is usually best used for MOS (without sound) b-roll. This has the temporal resolution to play at half speed (slow motion p47.96) without frames being interpreted.

p48 is double p24. This is usually best used for MOS (without sound) b-roll. This has the temporal resolution to play at half speed (slow motion p24) without frames being interpreted.

p50 is double p25 and is sometimes called and sometimes called "frames for fields". This has the temporal resolution to play at half speed without frames being interpreted. It also provides full frames that can be interpreted as fields for i25.

p59.94 (also called p60) is double p29.97 and sometimes called "frames for fields". This has the temporal resolution to play at half speed for without frames being interpreted. It also provides full frames that can be interpreted as fields.

p60 is double p30 and sometimes called "frames for fields". This has the temporal resolution to play at half speed without frames being interpreted. It also provides full frames that can be interpreted as fields.

High frame rates like p120, p240? Like any of the higher frame rates are great for b-roll without sound. They have the temporal resolution to run at lower frame rates without interpreted frames.

Drop and non-drop timecode (which can also be written as "time code") are unique to 29.97 and 30 or multiples of it. With drop frame timecode, two frames are renumbered every minute except for every tenth minute to keep pace with a real-world clock.

How does one pick a frame rate? Delivery settings. If you have to deliver i60 (but really i29.97 because someone rounded up), then your source footage should be i60 and your edit settings should be i60; however, your source footage could also be p23.976 or p24 using 3:2 pulldown later - but do not mix and any of these if you want your show to pass quality control. If you have to deliver p23.98 (but really p23.976 because someone rounded up), then your source footage should be p23.976 and your edit settings should be p23.976.

Why do frame rates get rounded up when it's a cause of so much confusion? Good question. There's the desire to simplify things. 30 is easier to write than 29.97 and 24 is easier to write than 23.976. It's up to us to know that 480i60 is the same as 480i29.97 and the same as 480i30 and the same as 480i59.94. It's also up to us to know that p24 might really be 24 but could be p23.98 which is really 23.976.

What else? I've seen changing from 23.976 to 24 be called "pull up" and changing 24 to 23.976 called "pull down"; however, those are just frame rate changes and the terms in this context should be avoided because pull down is, by definition, 23.976 or 24 to 29.97 or 30.

Remote Index

Hello R Neil Haugen,

I think your proposed workflow is best and will give you most long term flexibility.

I suggest shooting 23.98p or 29.97p and doing a conversion at the end or their specific delivery requirements. (I haven't used AE to do conversions before.)

R.