Rear Screen Projection
Posted 10 September 2007 - 06:23 PM
I will be shooting a short on kodak 5222 and one scene will be a limo with rear projection background. From what I have looked into so far using a digital projector is probably the way to go. But I am wondering about exposure, distance the projector will need to be from the screen, what kind of projector , screen etc etc would be best. Do I need to be concerned with any flicker issues etc etc
Would love to hear some first hand experience
Posted 10 September 2007 - 11:09 PM
Dealing with a digital projector, are their sync issues (just like filming a TV screen)? Is there any special way to orient the projector so that the lamp doesn't show through the screen?
I'm sure those who have done it before could offer some special pointers to problems that can't be predicted or expected.
Posted 11 September 2007 - 06:25 PM
Will I need to shoot at 29.97 because the digital projector would have a frame rate of that? What kind of projectors are out there? I would love to hear some options
Posted 11 September 2007 - 07:34 PM
A DLP projector would probably work quite well. It gives you picture pretty much all the time, frames change without much black between. Shoot some tests to see if you have problems with getting two different RP frames in each new frame you shoot. If your plate is film shot at 24 and transferred with 3-2 pulldown, you should be able to shoot the DLP RP at 24.
Posted 13 September 2007 - 03:30 PM
Posted 13 September 2007 - 03:39 PM
Posted 13 September 2007 - 08:07 PM
Im figuring I need to have the image be as bright as possible to have a chance at lighting the scene and getting enough exposure out of the screen
Posted 13 September 2007 - 11:24 PM
You should get a LCD projector to avoid any possible flicker with your film camera, and it should be something that can project at least 2000 - 3000 lumens. The great thing about shooting your background plates on video is that you can tweak them and time them to suit your needs exactly for your plate work (even though film plates can't be beat). I did this last year, shooting a super 16 short, it was a driving sequence at night in the rain. I shot background plates with a PD 150 (like they do, or at least use to, in the TV show 24), shooting them both in focus and out of focus (I enmded up using only the out of focus plate work)
What I found helped a lot was understanding the angle and focal length I would use for each shot during principal photography, so you can roughly match the same angle of view/circle of confusion (again, roughly), that you would attain if the background were actually real. After the footage was shot, I took it into final cut, timed it to my liking and made a loop of each angle I would be shooting in the car that would run for 10-15 minutes (so I we wouldn't have to rewind the appropriate angle between takes). As for the screen, I had a 14 wide by 10 high rear projection screen that was placed about 15 - 20 feet from the car. I was on the inside shooting out towards the driver from the backseat, so I was seeing partially out the windshield and partially out the drivers side window. The wider value was on a 16 mm lens, I believe. Either way, the screen was just big enough at the distance it was placed to fill the field of view.
My main reference for this scene was the driving sequence in fight club, the one with the big car crash in the rain at night. The int. car work was done on stage with 70 mm rear projection plates (I think, it says in the commentary), but it's great to study the way Jeff Cronenweth combined interactive lighting, color temp mix, etc., all smoothly integrated with good plate work for the scene.
Anyways, hope that helped. Good luck.