Shooting a Drive-In Theater screen at night

Matt Fels · February 9, 2010

Hello,

I am a student at SUNY Purchase, producing my thesis film. In it I have a scene where a character wakes up on the ground at a Drive-In movie theater, a movie in progress on the screen.

I've locked the Drive-In location, they only project 35mm. Obviously the content of the film playing on screen is important to me, I've been on eBay looking for 35mm trailers that might be appropriate, but I got to thinking that an easy chroma key, or luma key I guess, effect would be much easier. Or even a garbage matte on the geometric area of the screen, unless something crosses it.

I haven't chosen a format yet, probably Super-16, but possibly HD on the Panasonic HPX. Assuming I'm shooting Super-16, and finishing digitally in FCP, how hard would it be to key in the perfect footage on-screen, something I rip from a DVD for instance?

I'm guessing I can run the 35mm projector with no film in it to overexpose the white-screen, worry about lighting the minimal action on the ground in front of the screen, and then in post Luma Key out the bright white screen, and replace it with whatever I want.

Is there a better way to do this? Will this work? Any thoughts?

Thanks.

-Matt

John Sprung · February 10, 2010

I think you're on the right track with luminance keying this. Depending on what kind of projectors they are, you might be able to take the shutters out. That'll get you clear of any sync problems and get you more light. If it's a changeover house, run both projectors. One more thing to think about if you're running open gate for long periods of time: You're putting a lot more heat than usual into those projection lenses, so rig fans for them and drop the dowsers when you're not shooting.

If you shoot film with the shutters still in the projectors, remember that in terms of time, what you see in the finder is exactly what you don't get on the film. So if you do some start/stops to try to sync up, you want the dimmest screen in the finder.

One more thing: Check the projectors with the RP-40 loop after you're done to be sure that you haven't made a problem for the next show.

-- J.S.

Matt Fels · February 10, 2010

I think you're on the right track with luminance keying this. Depending on what kind of projectors they are, you might be able to take the shutters out. That'll get you clear of any sync problems and get you more light. If it's a changeover house, run both projectors. One more thing to think about if you're running open gate for long periods of time: You're putting a lot more heat than usual into those projection lenses, so rig fans for them and drop the dowsers when you're not shooting.

If you shoot film with the shutters still in the projectors, remember that in terms of time, what you see in the finder is exactly what you don't get on the film. So if you do some start/stops to try to sync up, you want the dimmest screen in the finder.

One more thing: Check the projectors with the RP-40 loop after you're done to be sure that you haven't made a problem for the next show.

-- J.S.

Thank a lot,

I think I'll end up going with HD, the shoot is coming up rather quickly and I'm not as well prepared as I'd like to be to shoot film, and don't feel comfortable asking the drive-in owners to remove their shutters. I think with the shutters in, even one projector should be bright enough to blow-out the screen sufficiently for luma key, that way I can change over when it's getting too hot, and save myself the fans, and the risk to their equipment. Plus I won't risk any strobing on the screen if I play with the synchro scan on the camera.

Also I plan on ripping the footage from a DVD and feel like I might have some trouble matching it to the 16mm plate.

Any more thoughts greatly appreciated.

-Matt

Chris Keth · February 10, 2010

I think with the shutters in, even one projector should be bright enough to blow-out the screen sufficiently for luma key

I wouldn't be so sure. Have you measured it? Movie projectors aren't really all that bright by lighting standards. They're bright lamps but they're also many feet away, particularly at a drive in. At the very least, go spotmeter the screen. I could be wrong but you don't want to take that chance and make keying a nightmarish experience.

Matt Fels · February 10, 2010

I wouldn't be so sure. Have you measured it? Movie projectors aren't really all that bright by lighting standards. They're bright lamps but they're also many feet away, particularly at a drive in. At the very least, go spotmeter the screen. I could be wrong but you don't want to take that chance and make keying a nightmarish experience.

You may be right. Unfortunately I won't be able to really tech it out too thoroughly before I show up. I'll shoot HD video, and if need be use both projectors, I'm just assuming that the white screen, shooting exterior night, should be bright enough to blowout the HD camera. It's a small portion of the scene, and I'm thinking I might just silhouette the actor against the screen, and hopefully the magic hour blue/purple sky behind it. That is to say shoot natural light but for the projectors.

Ryan Thomas · February 11, 2010

You should just light the screen yourself. I don't see anything preventing you from doing that...definitely make your key a lot better too.

Matt Fels · February 11, 2010

You should just light the screen yourself. I don't see anything preventing you from doing that...definitely make your key a lot better too.

We're talking about a 40 foot wide screen, starting about 12 feet off the ground, the top edge about 35 feet off the ground. I'm a student on a less than shoestring budget, if I'm lucky I'll show up with a rented 1200W HMI, and 2 Arri 650's, and some miscellaneous smaller lights. I don't have near the power or wattage, or grip equipment to come close to lighting it myself.