Which blue for blue screen?

[Jay Thompson]

Here’s a link that talks about both.

https://www.seanet.com/~bradford/bluscrn.html

Jay Thompson
Thompson Visual Design & Storytelling
7 Marjean Ct.
Kirkwood, MO 63122

[Tamanegi65]

I’ve read that article – mainly it discusses the Ultimatte and Chroma Key keyers and what they can do. It does touch briefly on paints – but doesn’t have any info to help me decide which paint to use for keying with Keylight?

[Betty Boop2]

I mainly used green screen (material) recently and have had great success with Keylight. It’s been some years sense I’ve been in a studio situation with blue sceen. I’m sure someone will chime in on that.

If you have not seen Andrew Kramers tutorial on Keylight, do a search for it. It is VERY, VERY informative.

Jay Thompson
Thompson Visual Design & Storytelling
7 Marjean Ct.
Kirkwood, MO 63122

[Derrick]

Go to this website:

https://www.rosco.com/uk/scenic/ultimatte.asp#SPECIFICATIONS

There is an email address at the bottom, I use there Ultimatte Green screen video paint since I shoot HDV.

I’m sure they can tell you what the right blue product is for film?

– Derrick

[Chris Smith]

Either will work fine. The goal is to have it show as close to 0,0,255 (in 8 bit space) after it’s sampled into AE. I would worry more about lighting it right than anything. Besides when your film is transferred, your colorist can balance the image so the blue is as pure as it needs to be. Which may throw your FG elements slightly off color, but after being keyed they can be rebalanced. But the most important thing is that the key color is distinctly different than what you want to keep.

So in conclusion, I would pick what ever color is the cheapest to paint the cyc, then have the colorist color the film to look good for your FG subjects and I’m sure your blue will easily be in the ballpark for a good key as long as it’s lit well and at a good exposure.

I did a grnscreen shoot a couple of months ago where I needed to paint the entire cyc due to large scale shots. “True” chroma key green paint was insanely expensive, so I used a third of that mixed into “Common” bright green paint which was a tiny fraction of the cost. The key was great.

[Derrick]

I think this would be a good watch:

https://www.digitaljuice.com/djtv/segment_detail.asp?sid=95&sortby=&page=1&kwid=0&show=this_week

– Derrick

[Tamanegi65]

Thanks for your comment. Most our shoots are green on HD (usually VariCam) – I’ve been experimenting with not lighting the green so hot (but still even) – also because of the chroma fringing I get when the talent has dark clothes – the bright green to dark contrast edge seems to cause DVCPROHD to cause purple banding.

Anyway – my understanding is the Chroma Key blue paint is not as bright as Ultimatte blue paint – so to not have the cyc too bright do you think it would be better to go with Chroma Key blue?

[Chris Smith]

To me having a brighter paint means you don’t need to use as much light which can help you get a smoother result. I mostly shoot grn but when using blue, what helps the DP and gaffer get the lighting smoother is to set the video assist monitor in “blue only” mode (typical on any Sony monitor). Then turn the contrast knob all the way up and the brightness way down. It will make the monitor then show the screen as a dark greyscale where it clearly shows you the dark and bright spots.

Also I keep the talent Waaay away from the BG. I always use the biggest stage the studios have and make sure the FG element isn’t remotely close to the keyable area. Then we usually light the screen with a bunch of diffused Skypans and some Kinos here and there. That way there is minimal chance of spill and it puts the screen in another focal plane putting it more out of focus making it smoother.

[Steve Roberts]

[Chris Smith] “… but when using blue, what helps the DP and gaffer get the lighting smoother is to set the video assist monitor in “blue only” mode (typical on any Sony monitor). Then turn the contrast knob all the way up and the brightness way down.”

Good tip, Chris. Thanks!

[Chris Smith]

Well I have to throw SOMETHING of substance into a post instead of implying one should read the manual all the time 🙂