AE Tracking At Half Frames?!?!?!

[Anthony Sipsas]

The only conclusion I was able to came up with was that the Sony F800 we were using to film (at a smaller shop that had older equipment) was not very effective at properly achieving pulldown. There were several settings on the F800, and the DP happened to want to get the footage @ 23.976. I have no idea why, as we were never consulted in post to what frame rate we would prefer to work in but the DP chose 23.976, and thats all i had to work with. we did not have the budget or time to reshoot. The main thing to know in that situation though, is only after researching the F800, we found that the camera only films in 29.97, so any other frame rate/setting is going to have problems as its not native to the internal workings of the camera.

As far as the physical process of getting 23.976 footage out of the SONY F800, as I said it actually films in 29.97, does a 3:2 Pulldown (as Dave had suggested earlier), within the camera before it records it to XDCAM. You cannot override this process.. If you are on an SONY F800, it natively records in 29.97, so it would probably be best to save to disc @ that framerate as to not add in more “problems” into the pipeline. I have always personally believed that one should always work in the native frame rate of the camera all the way through post, and only change frame rate for delivery as to reduce any variables that may complicate things. I am not sure how this would play out for something thats timed to music (such as a film though), because most of my work has been short form (Interactive, web commercials).

I would still have to stick with what I said on not changing FR as I personally believe that its the DPs responsibility to speak with a post supervisor, and/or research whats going to happen to be needed to be done technically down to delivery, and choose to make a decision with their camera that can balance art vs technical necessity/practicality.

The “Samurai” from atomos was also completely useless. Both (XDCAM and Samurai) are set to 1920×1080 23.976 in camera, and reflect that when i check the info on the clips.

The problem is that both the camera and the Atmos labeled 23.976 as progressive when its not. 24p is progressive, 23.976 is not. This is why i question why would a camera like SONYF800, or an ATMOS product label it as such? They aren’t fly by night companies by any means…

Again, reading my previous posts, it sounds funny, but I can assure you I was objectively reading the settings from the camera. This is not a reflection on my knowledge, but rather a reflection of what I am reading from the users manuals, and in camera settings.

As far as your DSLR, I would do a few things:

1) Research if your DSLR films at a specific Frame Rate. What Id like to eliminate here is when you switch to a different frame rate, if the camera is natively filming, and writing to disc/card @ that frame rate, or if there is a software process thats being added on top of a specific format that the camera can do. What I mean by that is if for example the camera can only film @ 24p, (and this is stated by the manufacturer as the sole capability of the camera natively), that would mean when you switch it to 60fps, 30fps, etc that there is some sort of processing going on within the camera that alters/converts the footage to the other setting before it saves it to the card.

Obviously there are reasons to do one over the other, but its probably good to be aware of this, as it can affect your footage. Its probably smart to know this information about your camera so that you can choose its native settings and change anything after post (when you deliver), unless something is really needed like going from 24p- 60p in camera for slow motion in post or similar example…. But then you know that you are choosing to do something that may affect the footage, but its necessary. The idea is to avoid problems if they are unnecessary.

2) The other issue was the F800 had a LOT of noise in the footage. Make sure your camera settings are such that you are receiving proper light, and proper film speed. I don’t believe the Cannon cameras have these settings adjustable, so probably just make sure your scene is properly lit. I know cannons have amazing low light sensitivity for DSLRs, but in comparison to pro cameras, they are still very noisy.

3) The last thing I would do, is I would add an extra step in your workflow specific for tracking. What I mean by this, is SPECIFICALLY for tracking, I would export an uncompressed frame sequence at the same framerate as the native footage. Import & Use the image sequence for tracking, but only use it to acquire the tracking data. Once you have your tracker solid and sticking, save/bake, & replace with source footage, and finish compositing as needed.

**we can only do the best we can with whats given to us, so hopefully the last step will help you deal with the footage you have already shot. Keep the other steps in mind (food for thought) for knowledge so that you can make decisions that will make your workflow more fluid moving forward.

Hope that helps a bit. Please keep me posted on your findings as well….

[Neil Benjamin]

Just came across this 4 year old thread and had the same problem.

After digging through everything, I realized that the problem is that my clip is stretched to something other than 100%. Once I set my stretch back to 100%, it tracked on the keyframes again. Hope that helps!