-
Greenscreen footage, how much ruckus?
ello,
I have a few questions about workflow.
Here is a still of what I’m working on
https://www.theridding.com/plates/experimentMushroom.jpgThis was shot on 35mm, then telecined to DigiBeta, and I now have the clips as uncommpressed 10-bit Digital Voodoo.
I’m having some trouble getting a good key with keylight, mainly just hard edges, and the ‘status’ view is all a mess. I know shadows will make some of it difficult.
Was this process sufficent for filming? as this was our first attempt @ filming, now keying ;).
Or does Keylight take some getting used to.I have about 20min of different scenes, all pretty much the same lighting. Is there a way I can streamline the creation og gargade mattes?
Regards
_Eric
-
7 Replies
-
It’s not ideal lighting for greenscreen so it’ll take more work on your part. Keylight has a lot of subtleties that need adjusting to really get a good key. You may also need to do it in different sections. Like garbage mask his head and do that as a layer, then to the body, etc..
The luminence of the green is all over the map so it probably won’t work well in one key alone. At least he’s bald and you don’t have to deal with whispy hair.
For future ref, adding more backlight to him will help the edges a bit. Also when you don’t need him on the ground, get him like 10-15 feet away from the greenscreen and then get the camera back from him a good ways as well. This way you put the screen more out of focus and reduce any likelihood of spill on the subject.
If you did it again, I would’ve lifted him up on a plexi floor a few feet above the greenscreen and then lit the floor under him a lot smoother. But this is only if you don’t need the shadows.
Chris Smith
https://www.sugarfilmproduction.com -
Thanks Chris. Thats what I was afraid of. Although this was the worst case of the footage we shot, I guess we need to find a better way to shoot, and unfortunately we had to wait and see untill we could get $$ for telecine(I will say it looked cleaner @ the telecine house, could the digiBeta conversion effected the green lum?)
I guess we should go around the green screen with the light meter, for these shots we just took readings on the talent, measured the distance, set the f-stop and distance rings accordingly and started filming. I dont mind bout the shadows as he’ll be in a cave, so some convincing volumetric lighting should work.
Any other tips on setup would be great. We started with fabric, but it was absorbing to much light and had alot of wrinkles, so we switched to paper. We are using 4 250s from the ceiling to light the screen, and 2 1000’s off bounce boards for the talent.
If the final output of the project is DVD 480p should I de-interlace now, while editing?
Thanks Again
Regards
_Eric
-
Well technically DigiBeta compresses video 2:1 but it usually never effects a key. Ppl make great keys every day from the Film to Digi pipeline. If it looked better in the transfer suite it was probably that they: 1. had a much better monitor than you’re looking at 2. They were looking at their HD monitor while the transfer was to SD (unlikely).
It looks like they didn’t do much in the transfer. I’m guessing you asked for it flat?
As far as lighting, there are so many ways to do it. We usually use skypans to light the grnScreen, then if it’s one person, in close-ups, we’ll use all Kinos for key and back light. If it’s a larger setup or more than one person, then it’s 12x Muslin with 9-lights behind them.
As far as light metering, you don’t HAVE to be so precise. Often just on your video assist you can tell there is unevenness. But yeah, just stand near the cam and take some spot meter readings of various points on the screen and make sure they are relatively even. Especially around the talent. The screen doesn’t need to be good at all elsewhere in the shot, just at the edges of the person. But for example, because of the paper’s sheen, where it bends you have quite a bright highlight. Then on the floor, it’s very dark.
With some work this is still very keyable. However the closer your key is to even, the less work you do on the post side. Ideally if it’s all even then you can key it equally and not break it up into multiple keys with different settings for each area of the shot.
Also next time you’re in telecin
-
Thanks again for the responses Chris.
I’m pretty sure they were using a better monitor, some pro one, and they would switch views between the digibeta output and the images coming from the divinci.( I use a 23″HD & 20″HD apple displays)
As far as flat, we really didn’t know any better. This was our 2nd session and first attempt @ green screen. So we asked for something ‘basic’ and we could sweetin in FCP.
Im not sure what ‘video assist’ means, we are amateurs and trying to learn as we go, do you mean use a camcorder as were shooting to get an idea? Thats why we were only trusting the light meter as we wouldn’t know what we got until we get it developed. I had noticed the sheen from the paper, but thought that could be easily removed with a rough garbage matte before I start keying.
I did ask the engineer, but said he had no keyer in that suite we were in, I also asked for colorbars on the transfer but didn’t get those either. The colorist said I should be able to get a good key, but for us ‘little guys’ I’m sure they say whatever.
On most shots we did take a few frames with ‘no talent’ then added the talent, I hoped that somehow this would help, so thats good to know. I’ll have to play around keying the empty pass first, then try that matte on the subject one
Thanks for taking the time
Regards
_Eric
-
First of all DaVincis have a keyer in the form of a ‘kilovector’ the same way they grab a color and tweak it they can grab the green and if nothing else turn it all pink for example to see that it’ll work.
Video Assist: Almost all film cameras except really cheap ones have a video tap. When light comes into the cam it hits a splitter and the tap (CCD cam built in) gets some of it and outputs a video image for framing reference. They usually look like poo, but that’s what clients watch to know what’s being shot. On almost all sets a guy records this into a computer or tape deck for playback. For example if I’m working with an actor and we did a handful of takes, I’ll go back and watch the tap off the computer to see how they looked and if we need changes. We even pre edit the spots now on the computer while shooting to make sure timing and continuity are working well. Then we output this edit for the post house for ‘inspiration’ for doing the final edit from the film transfer.
When we use a bluescreen, we use the tap to balance it. Since most sony monitors have a button that shows just the blue channel as a greyscale image, we hit that and drop the brightness down. Then it’s like magic, it’ll show you where your hot and dark spots are clearly as a grey scale map on the screen. Too bad they don’t have the button for the green channel.
Yeah, lots of folks get flat transfers knowing they’ll color it later. I do this a lot as a backup on a second deck. So when they do the dailies to one deck, I take the direct output of the Spirit to a second deck. This way I can do my own cut and color it in Shake later.
Chris Smith
https://www.sugarfilmproduction.com -
Other quick note. Bring a good Digital SLR cam to set with you (like a Canon 20D or the like) and take ref pictures as well. Some of these cameras have remarkably film like response and will give you a great idea of what it’ll look like. We use it all the time. If I’m uncertain how the DP lit something, I’ll take pictures of the shot from the main cam’s POV with the 20D and we’ll discuss changes. Works very well and looks extremely close to what you’ll get.
What 35mm cam did you use? It may have had a tap on it.
Chris Smith
https://www.sugarfilmproduction.com -
Good to know, thanks.
Our camera is old school(late 70s) Russian made 35mm, so no such luck with vid assist
Regards
_Eric
Reply to this Discussion! Login or Sign Up