Filters for greenscreen lighting

[Jim Ross]

Hi Nick,

Thanks for the input. Is that Peter Jackson? He looks so different! Weight, hair, beard. Wow what a change.

I agree 100% with your comments on the Ultra2. And all of those reasons are why we use it on occasion. But we are moving to an all Mac studio and Ultra is PC only. So something new will take its place. We are also moving from an XL1s to shooting HD with a Pany HVX200, so all these things concern me.

When I first used Ultra I was using 5,000 K fluorescents to light the blue screen and tungstens to light the talent. The results were awful. Once I got some Westcott Spiderlites and shot everything but the hair light with 5,000 K everything changed. I am almost paranoid of shooting with less than 5,000 k now. Gimmie sun or fluorescents. I am about to start experimenting with the HVX200 now to see what I will have to learn and unlearn.

But hey, that challenge is what makes this great, eh?

Jim

[Nick Jushchyshyn]

The "Ultra" products for the Mac pipeline are :
Conduit
and/or
dvMatte Blast

Again, I'm not affiliated with these products in any way, nor do I get a kickback. In fact I only use them occationally, but many people I know that do TONS of video keying (as in hours of material per week) swear by these.

The guy that started this thread might be able to help if you have questions about them.

Have fun.

[Ben Syverson]

Originally Posted by Jim Ross

Applications like Ultra2 (which I use and love) assert that the background color is not so important. Your illustration of the importance of the color has me thinking very differently. From your tests I would venture that the chroma screen itself will have a lot to do with the results? After all, all chroma screens are not created equal. Being in the biz of writing this kind of software, do you find this to be true? That you get what you pay for and cheap green/blue screens give you lesser results?

Sorry for the delay in getting back to you!

My response to the above would be: abso-f*cking-lutely. :) The issue is not how much you pay for the screen, but how good it is. Getting the right light filters and cheap paint to perform is what I'm up to, but if you want a sure thing, Composite Components has pretty much perfect screens and bulbs.

Screen color definitely counts -- it determines the amount of raw color difference in your matte, and lighting color can help you make a good screen a great screen. No matter what the technology, the more pure the screen, the better the key. End of story. Even lighting is ideal, but a screen correction plate can save even terrible lighting, so color is crucial.

Regarding Holywood, it comes down to this very simple fact: they have enough money to "fix it in post." You don't. :) I know of multiple big budget FX productions that have gone to the expense of shooting against greenscreen, only to have artists (aka brand new recruits) rotoscope everything because the stuff they got on-set was basically unkeyable.

This is like doubling your FX budget for no reason. DPs think they know it all because they've shot a lot of blue + green screen. What they don't know is how difficult their shots were to extract. They internalize myths that they completely made up ("screen should be 2 stops darker than the subject!" or "some poorly-lit green back there is better than nothing!") that have no basis in reality. The next thing they know, the final composite is on the screen, and they think they saved the day, when in reality, it took three 22-year-olds staying up all night roto'ing the shot. :P

So don't pay attention to what big productions do. They have to get the shot on the day and move on, because their combined costs are like $100,000 an hour. You have the luxury of getting it right, on the cheap. :) Asking your talent to hang tight while you fiddle with the lighting for half an hour doesn't cost you anything, but it will save you tens of hours of roto.

Regarding Ultra: if you're getting good results from them, don't change anything! What the new dvmatte strives for is the ultimate in fine edge fidelity. It might not be important for talking heads in a corporate shoot. But if you're doing narrative filmmaking, and need to reproduce every flyaway wisp of hair, dvmatte is your tool.

I will also say... as far as I know, dvmatte is the only keyer in active development. Serious Magic (Ultra) sold out to Adobe, as did CFC with Keylight. Ultimatte (aka AdvantEdge) hasn't seen any new technology for over 10 years. (!)

[David Parks]

Originally Posted by Ben Syverson

I

Since filters are subtractive, a good green filter will hold back most of the red and blue light, but allow most (but not all) of the green light to pass through. So for a relatively small decrease in exposure, you can almost eliminate the red and blue light which is corrupting your greenscreen.

- ben

Ben,

Did you light with tungsten or daylight balanced. Which filter do you think would work best for daylight balanced.

Thanks for the very very helpful info.

Cheers, David

[Ben Syverson]

Originally Posted by David Parks

Ben,
Did you light with tungsten or daylight balanced. Which filter do you think would work best for daylight balanced.

David,

I used fluorescents with standard "cool white" bulbs. They're kind of halfway between daylight and tungsten, clocking in at 4100K. You can use anything to light the screen, as long as you manually white balance the camera to the lights, and then add the filter. Since it's a hassle to get the filters on and off the flos, I white balance off a separate set of unfiltered coolwhites, and then bring in the filtered banks. Lee 738 will be the best filter if you follow that procedure.

If, on the other hand, you want to be able to set your camera to the default daylight setting and not have to manually adjust the WB, then you'll have to experiment with your exact lights and camera to figure out what filter will be best.

Hope this helps!

[Jim Ross]

Ben,

I translate "abso-f*cking-lutely" to mean yes? Heh heh.

I am happy with "good" results from Ultra2, but would be happier with "insane results" as you put it originally. Right now we are doing 99% web video and Ultra is fine for that. But we want to do more DVD and Doc work, so yes I want to graduate to a new level. Movning to HD makes this even more critical. I will check out your dvmatte for sure after this post. I see dvmatteblast, dvmatte pro, etc. Differences? Feel free to email me- jimross81(at)comcast.net.

I checked the Composite Components website, but no way to order. Do they sell through dealers or just to the industry? Do you know of some other reputable names for a screen that a small studio could get?

Jim

[Ben Syverson]

:)

blast is our easy to use realtime keyer, whereas pro is deeper and more powerful... The current version of Pro is a bit out of date, which is why we're releasing a brand new realtime version very soon. It will be available for Final Cut Pro at first, and then a variety of other platforms hopefully soon afterwards.

Composite Components is great, but their website really needs some lovin'. :) The best thing is to email or call them directly -- I think all their contact info is available on the site. If you tell them I sent you, I think they may give you a bit of a break.

[Jim Ross]

Thanks, I'll give them a call!

Jim

[Kevin Loh]

Originally Posted by Ben Syverson

:)
Composite Components is great, but their website really needs some lovin'. :) The best thing is to email or call them directly -- I think all their contact info is available on the site. If you tell them I sent you, I think they may give you a bit of a break.

I couldn't believe the website for an academy award winning green screen supplier. Their site does indeed need some lovin.

I've tried doing some elementary keying from some Panny DVCPro stuff using After Effects and Premiere. Man it's not easy. I kept on getting lots of green spillover at the fringes. The guys at Stargate sure have a great GS reel!

YouTube - Stargate Studios Virtual Backlot Reel 2009

[Jim Ross]

Wow. Flash back! Stumbled upon this post that I had commented on almost three years ago. My have things changed! Now I shoot blue screen and green screen all the time and I remember now how I used this thread to build my studio and choose my equipment. I love this site!

Jim
High Definition Video Production In Atlanta: The Ultimate HD Productions

[Jon Doughtie]

Doing some other searches, I came across this thread. I usually do not try to revive old, old threads. But the information in this about green screen work is worth reading again.

The technology has moved forward over the years. But the techniques in here will still serve well. Ben Syverson, you made a great contribution with this material.