would you go 24-frame for glreenscreen if you had a choice?

[Todd Terry]

I think it makes little to no difference as far as keying quality goes, and any (if there is any) would be negligible.

Far more important is knowing the other parameters of the project for which this is intended. Is this a 24p project, or a 30fps project? What other footage is being cut with it? Is there video for a background plate and if so what is its frame rate? If 24, is it true 24 or 23.976? Above all, the big question is what are the specs of the “master” finished project, and that’s what the frame rate should be.

It’s all a matter of preference and look, of course. When I’m shooting for myself, I invariably shoot 24p (23.976fps). On the very rare instances that I’ve been a hired gun and shoot things for other people, I will match the frame rates of their projects, or shoot at the frame rate they request.

I’m personally not a big fan of 30fps, I just don’t like the look. It’s not as cinematic as 24fps, and not as “live” as 60i… it’s caught in an unpleasant gray area somewhere in the middle. But hey that’s just me.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Chris Wright]

The framerate doesn’t matter. its the shutter speed that will kill you. motion blur is tougher to remove once its burned in, but you can re-add it digitally with reelsmart motion blur or optical blur.

Another thing is, stay away from interlaced! it will make it 4 times harder to fix as each field will be blurred and you’ll have half the information you would even get with a progressive scan. you can add fields in post as well. easy trick is to to shoot double your framerate and then turn each frame back into a field.

[Ryan Elder]

I would say the less frames the better cause then that is less processing to do for layering one layer of footage over another.

[Chris Wright]

unless you’re doing ‘Lord of the Rings’ level cgi, I don’t think going from 24 to 30fps is going to matter that much in terms of composite render time.

[Chris Santucci]

As mentioned, frame rate doesn’t matter. It’s ALL about shutter speed, and having the greenscreen at a proper evenly lit level relative to your subject. I’ve done a LOT of greenscreen shooting and posting and don’t believe I have ever worked with 30fps footage.

https://www.santucci-cinematographer.com

[Todd Terry]

Nah, I’m going to contend that it’s ALL about the f-stop.

I don’t think I’ve ever had any compositing issues because greenscreen footage had motion blur… and I really hate the stacatto look of too-high a shutter speed (and artificial motion blur just looks so, well, artificial). Also Mark said these were interviews he was shooting, which of course are not exactly action scenes. You’d probably see little to no motion blur in a talking head interview.

But I have seen compositing issues frequently because edges weren’t clean/sharp, because depths-of-field were to shallow to keep all screen elements in razor focus.

I’m one that frequently shoots wide open, and with medium-to-longer lenses at f/1.3 or so you can have razor sharp eyeballs but focus quickly falling off so that, say, ears are a bit soft… making a key tougher. In these cases for greenscreen work I force myself to shoot with higher f-stops…. but still always with “normal” shutter speeds (one over twice the frame rate I’m using).

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Chris Santucci]

Using an adequate depth of field is a given for any kind of setup, greenscreen or not, but yeah, borders especially need to be sharp on greenscreen. I almost always shoot all my footage at 1/125 second and never had anyone complain about how it looked. Even someone sitting in a chair talking may decide to wave their hand(s) around, so I tend to not take any chances on greenscreen. And in fact, the only time I had issues in post was with motion blur because again, unsharp borders. If anyone wants to see how awful 1/48 second footage really looks, watch a sequence with movement in it, frame by frame. Even moderate movement is completely blurry at that speed.

https://www.santucci-cinematographer.com

[Chris Wright]

I’m trying to visualize what you’re saying. It makes sense that the actor needs to be in focus, but its actually beneficial for the greenscreen to be out of focus to blend all the fuzzy dots together(unless you’re 3D tracking). Now, if your actor is far from the circle of confusion, then you might lose some sharpness, but a sharp greenscreen? I just don’t get what you’re talking about.

[Todd Terry]

Well 1/125th is about a 70° shutter, which is quite narrow indeed.

That is, in my opinion, going to give footage that gawd-awful staccato look, which is usually undesirable unless you are, for some reason, intending the footage to have the narrow-shutter look. It can be done well and appropriately (i.e. Saving Private Ryan), or terribly (Gladiator, anything that happens to be Fast and/or Furious or any one of a zillion action movies where it’s used to make things look more, well, “action-y”).

Personally, I hate that look like poison and never shoot with anything other than a 180° shutter unless there is a specific and compelling reason to do so. On rare occasions I might close the shutter a tiny bit for exposre reasons, and when I was shooting a lot of film one my 35mm cameras had a fixed 170° shutter so I was stuck with it… but 99% of the time I shoot with 180°.

Hey, that’s just me, it’s personal aesthetics taste and not an unbreakable rule.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Todd Terry]

No Chris, I’m not talking about increasing DOF so that the greenscreen is sharp, but that all of the elements that you are trying to key are sharp.

With an extremely shallow depth of field, you might have one person razor sharp but another slightly soft. Or if you are shooting a single headshot in a CU, the subject’s eyes might be sharp, but the subject’s edges (ears, top of hair, shoulders, etc.) might be a little soft. That might the the look you’d want against a practical background, but for compositing you’d be better off with a deeper DOF and hard edges.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com