Universal Frame Rate

[Tariq Peter]

I shoot at 25fps, 1080P but now I am thinking is there a point? Blu-ray does not support 25p so I end up watching an encoded file which stutters when my camera is panning as Encore has converted my footage to 1080 50i.

If I shoot at 24p will my life not be that bit easier? Less time to encode, supported by Blu-ray standard. Most DVD players play NTSC now so that should not be an issue.

Would love to hear your thoughts on this and if anybody else has started to do the same?

[John Carroll]

If you google "Bluray 25fps" you'll find a lot of discussion about this...

[Nigel Barker]

The stuttering is because you are panning too fast & will in fact be marginally worse if you shoot at 24fps.

While 25p is not part of the standard for Blu-ray when Encore authors the disc at 50i the Blu-ray players do the right thing & it is displayed effectively as 25p. It's analogous to teh way that some cameras record progressive within an interlace wrapper.

[James Manford]

I was thinking the same thing as Nigel.

It sounds like you are panning too fast. DSLR's are great for video, but they have drawbacks such as this.

[Jon Fairhurst]

Also, use a shutter of 1/50 or slower to reduce judder.

[Tariq Peter]

Yes, 1/50 is my shutter when I shoot at 25p. My next question is whats the main factor why hollywood films that are filmed on digital cameras like the RED, display fast and slow panning shots without any judder.

I understand that shooting on film is a different topic, but if I were to watch Act of Valor, which was filmed on the 5DMK2 would I see the same judder on the fast pans as I get?

[James Manford]

Personally I think they are using advanced editing techniques.

And RED probably has non-existant jello etc.

Hopefully some one more knowledgeable will answer as i'd like to know too!

[Jon Fairhurst]

There are ASC guidelines for panning. Here's my personal summary of the issue...

* When panning across a scene, limit the speed to about 7 seconds from edge to edge. So, if there is a tree at the right of your frame, it should take at least 7 seconds before the tree ends up at the left edge with a constant speed pan from a stable tripod. (ASC has a whole table for film size, focal length, degrees per second, etc, but it all comes down to the 7 second rule.)

* You can also whip pan. If the pan is drastic enough, it's unsettling and judder isn't really noticeable. So very slow and very fast pans are fine. It's the middle speeds that cause the problem.

* When tracking an object, you can pan faster than the 7 second rule. The eye will track the object, which is roughly stationary in the frame. Judder in the background isn't so noticeable.

* Other issues, like rolling shutter jello, handheld or jittery motion, and counter motion in the scene can make things worse. Test and use your best artistic judgement.

* Sometimes, you're hosed. When a football is thrown or kicked and you pan slowly, the ball will judder. Track the ball quickly with a wide angle lens (so the ball is relatively small) and the large, dominant background will judder. Tests have shown that you need 240 to 300 fps for perfectly smooth perceived motion in sports.

IMO, tracking motion is the key. If you go to a local park and pan randomly, the judder will jump out at you. Pan slow enough and it will feel boring, since the scene is boring and out of context. So you speed up the pan. And it judders. If you shoot this scene handheld, you notice every bit of shake and jello. But if you track a young woman walking or a kid on a slide - especially in a story - and the scene is no longer boring, the speed of the pan feels perfect, and the judder disappears. Also, you can shoot this handheld. Not only does the judder disappear, the camera shake and jello vanish as well - within limits, of course.

So when you watch a film by an expert with context, tracking and controlled pans, and then compare it to a handheld, medium speed pan in your backyard, this explains why the first looks great and the second looks bad. (Not to mention lighting, grading, and artistic framing.)

[Maurice Covington]

Good post Jon. I can't speak for the others but this will help me a lot. Is the ASC available on the internet for download? It sounds like something I need to become familiar with.

Thanks!

[Jon Fairhurst]

Unfortunately, the ASC tables are for sale only.

http://www.powells.com/biblio/61-9780935578317-1
American Cinematographer Manual 9th Ed. Vol. II by Asc Stephen H. Burum - Powell's Books

I believe that the discussion of camera stabilization is in the first volume, but the table is in the 2nd.

[Maurice Covington]

Thanks Jon. As a newer videographer, I honestly didnt know that this book existed. The minimal investment should be well worth the information contained within.