OT: How to shoot a drum kit against green screen?

Eddy Bee wrote on 4/16/2012, 1:36 PM
Does anyone have tips for shooting a drum set against a green screen? The big problem is the cymbals, which vividly reflect the green backdrop - depending on the angle, they can sometimes turn almost completely green. It's easy enough to manually mask them when they're stationary, but of course, they move wildly when the drummer hits them.

Is there a shooting or lighting technique that can eliminate the reflections? Is there something that can be done in post to manage the reflections in Vegas so the drum kit, including cymbals, keys properly?

I've been struggling with this one for a while, so any advice is greatly appreciated.

Comments

rs170a wrote on 4/16/2012, 1:44 PM
Having done this before, the only solution I found was to get as much distance between the drummer and the green screen as you possibly can.
Keep in mind that, as long as the drummer is in the shot against the screen, you can use the Bezier Mask tool in Pan/Crop to key out any unwanted garbage.

Mike
JackW wrote on 4/16/2012, 2:00 PM
You might also use a magenta back light on the drummer; this will tend to kill the green reflection quite a bit and shouldn't be objectionable in the final mix.

Jack
rs170a wrote on 4/16/2012, 2:24 PM
I tried the magenta back light trick and, while it works for people/clothing, it didn't work on the drum kit because it was way too reflective :(

Mike
ushere wrote on 4/16/2012, 9:24 PM
years ago we used to use a 'matt' spray that killed any reflection. it was, iirc, water based, but either way simply wiped off.
Former user wrote on 4/16/2012, 9:37 PM
Interesting gadget here.

http://www.planetdv.net/pdfs/ReflecMediaCVReview.pdf

Dave T2
rmack350 wrote on 4/16/2012, 11:20 PM
It's usually sold as "Dulling Spray"and, yes, it wipes off. I think hair spray can do a similar job, soap might do it too.

Art supply stores have similar spray products but they're usually permanent.

The thing about chrome and brass is that it's a lot like a mirror. You're not just seeing a green or blue screen ambiance, you're seeing a reflection of the screen. Actually, all surfaces work this way but most of them, like skin, scatter the reflection. So if you add a magenta backlight then skin would scatter a mix of magenta and green. Unfortunately, a very reflective and/or glossy surface won't scatter light.

The big problem with cymbals is that they move all over the place so it's really hard to control the angle of reflection. You can dull them and provide a lot of some other surface like (foam core) for them to reflect.

You only need green behind the subject. It doesn't need to fill the frame, although the matte might be simpler to pull if it did.

Maybe it's possible to pull two keys in stages so that you can work specifically on the nasty parts of the drum kit separately from the drummer...
rmack350 wrote on 4/16/2012, 11:37 PM
Dave,

What you linked to looks a lot like a front screen projection (as opposed to a rearscreen projection).

I saw one built years ago at a stage in San Francisco (they shot a lot of a Star Trek movie on the same stage-lots of square footage to work with). Basically, the idea was for the actors to perform in front of a reflective scotchlight wall. A projector would shine a motion projection onto the screen and it would all be reflected brightly back to the camera lens.

See http://en.wikipedia.org/wiki/Front_projection_effect
farss wrote on 4/17/2012, 1:21 AM
Maybe scrap the green screen altogether and shoot in Black Limbo and use a Luminance Key.
That as I've found out is harder than it sounds. You need a camera with low noise and you need a lot of separation between the black level and the subject i.e. use a large sensor camera and light the subject low key with lots of light.

Other option is rear projection which is expensive.

Finally back to green screen concept is to use a fluro green background and light it up with UV lamps. Getting this to work is going to be tricky and might be expensive and although I know it does work you've still got potential problems with reflections for the green fabric.

Bob.
deusx wrote on 4/17/2012, 3:01 AM
I assume the band/drummer will be playing along a pre-recorded track and faking it, so couldn't you just replace real cymbals with fake/non-reflective ones. They will not be making any sounds that will end up in the final recording anyway.

Kind of like they use liquid soap instead of milk when they do cereal commercials, because milk doesn't quite look like milk when filmed and it makes cereal soggy and crappy looking very quickly.
PeterDuke wrote on 4/17/2012, 3:55 AM
If the cymbals are shiny they will mirror something. What should they mirror in the final product?
Rory Cooper wrote on 4/17/2012, 5:04 AM
You can use magenta gels as said already on the subject lighting this will counter the spill from the green likewise yellow gel for blue screen. Set up a few magenta stage lights and narrow your focus on the cymbals. You may need a few. As already said move the drums further away from the screen will help. Trying to fix this in post is a nightmare.
rmack350 wrote on 4/17/2012, 12:32 PM
Usually, in practical situations with blue screen I've always used CTO (orange color correction gel) to wash out blue ambiance, but maybe yellow works better. No one's ever specified yellow to me and of course as a grip or electric I always had a lot more CTO on the truck than I did yellow gel. Same goes for adding magenta to backlights. With the advent of Kinoflos we started carrying rolls of plusgreen and minusgreen (magenta) in varying strengths.

Getting distance from the blue or green screen makes a lot of difference and is excellent advice if you can do it. Pull the subject away from the screen. Of course if they're going to perform everywhere in the frame then you'll need a lot more green wall behind them, but if they don't move around much then you only really need green where they are. Getting rid of the rest of the green will reduce the green areas that a cymbal can reflect.

If I was on a stage I'd probably want to build frames of (at least) 12'x12' silks or duvatyne and bring them in on the sides of frame to squelch come of the ambiance and to create my own reflective surfaces. And when going in for close ups I'd want some smaller frames walked in to try to control reflections.

If I was doing this as a hobbyist project I think I'd be trying to figure out how to make a virtue of imperfection.