24fps or 30fps? - cineframe24 or not?
 

Hi,

We are currently working in the field and are wanting to avoid problems mixing our footage in post. We are filming in high def with 2 different Sony Cameras: HVR-A1U & HVR-Z7U.

The latter can film true progressive 24P – as well as any of the other standard formats, while the former can only film in regular 1080i/29.97fps – and has the option of using Sony’s “Cineframe24” and “Cineframe30”. Our final output will never be transferred to film – but will be projected at a major world forum to its primary audience and broadcast in high def on TV to it secondary audience. To date, we have filmed all of our footage in 24P on the Z7U and using cineframe24 on the A1U – but we have only just begun and are considering a switch.
We are both directors not camera people/editors so please forgive our ignorance - any advice is very much appreciated, Thanks in advance for your input.

The real question is how are you delivering the video. If you are going to BluRay you could use 24P but if you are going to something else It will almost always be in 30 or 29.97. You lose a lot when you convert. All dvd is at thirty frames. That is the standard. BluRay does allow 24P so if that is how it is viewed, there you go. Of course if you are delivering your video on an hd tape format that would be different again.

Jason:

My response is purely anecdotal, based on my experience with Cineframe24.

First, I have the FX1, which I believe has the same characteristics in Cineframe24 as the A1U.

Second, most purists pounce on Cineframe24, indicating it is not true 24 fps, and indicate its cadence is screwy. The word is that it suffers in action shots.

With that in mind, I shot the FX1 in 60i most of the time, and never really experimented with Cineframe24. The understanding was the in a program like DVFilm you could actually convert to 24 fps safely (DVFilm - Digital to Film Transfers, Raylight Software for Desktop HD editing) I never bought that program, but I did buy Cineform, and I used it to convert my 60i footage to 24p occasionally.

Last year, I started shooting in Cineframe 24, just to see what the complaint really was and I was pleasantly surprised that in most situations, I got a very nice look. My process was to capture using Cineform, removing pulldown pursuant to Cineform's recommendations for the FX1 capturing at 24p.

In the end, what I am saying is take a look at the look you can get with Cineframe24 in your work flow by testing it thoroughly, and make a decision as to whether it meets your needs and will work for your customer.

If you do go the Cineframe24, I would suggest you remove pulldown during capture, using something like Cineform's Neoscene, so your edit masters are already in 24p.

My understanding is that while all DVD is 29.97, you preserve 24p cadence by adding pull down to the 24p footage to conform to 29.97 in the DVD conversion process. It does not change the nature of the 24p footage. In fact, in many HDV cameras, which shoot 24p, the recording is done the same way. Pull down is added to conform it to HDV 29.97 standards. Then when we process it to remove pull down, we have true 24p footage.

The rub with Cineframe24 was that it does not apply the pull down correctly, thus raising a potential for problems with film makers.

That's the rub. When you add pull down to make 29.97 to get a program ready to broadcast you add frames that were not intended by the DP. The Z7 actually will record in true 24P or 30P as opposed to HDV and miniDV which are both interlaced and use pull down to create an artificial progressive frame. Since they are delivering to television for broadcast it needs to be at 29.97, my suggestion was to record it that way. Fewer issues when the make their final delivery, which probably will be on tape or hard drive.