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#1 Albert Smith

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Posted 13 May 2008 - 11:16 PM

Hi, I am shooting a short project that is going to be done mainly using rear projection, I have a little experience with this as I used the technique a bit before, but the results weren't that great and and the projection was somewhat underexposed. so my question is what type of projector should I be looking to use? Were definitely going to project in hd...even though a majority of it will be a bit out of focus anyways, but assuring the projection is bright enough is of course a factor. My other question would be what type of screen should I be looking to use. It will need to be big. my guess in the area of at least 8-10ft wide, is this something I can rent at a film rental house or should i be looking elsewhere? Also, matching color temperature with lighting in the foreground, generally what is the color temperature of a projection, am I working in tungsten or daylight?


Thanks for any insight into this stuff you can give me.


-Jake Zalutsky
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#2 Joseph Nesbitt

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Posted 14 May 2008 - 09:02 PM

hey, as far as a projector goes, most are very expensive so I'm assuming your renting, these things usually go up in price by how good the bulb is and I'm assuming the better bulb means more light so prepare to dig into your pocket, as far as screen I know that in natural born killers Oliver stone projected of brick walls and stuff like that so you can probably use like a pretty cheap screen there are photography sites that sell them in the form of back drops and ebay might have projection screens but you can always just by a canvas, cheap big but they wrinkle so be careful.
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#3 Albert Smith

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Posted 16 May 2008 - 12:49 AM

hey, as far as a projector goes, most are very expensive so I'm assuming your renting, these things usually go up in price by how good the bulb is and I'm assuming the better bulb means more light so prepare to dig into your pocket, as far as screen I know that in natural born killers Oliver stone projected of brick walls and stuff like that so you can probably use like a pretty cheap screen there are photography sites that sell them in the form of back drops and ebay might have projection screens but you can always just by a canvas, cheap big but they wrinkle so be careful.


were doing rear projection so we will need a screen capable of that...I dont think front projection would work as there will be shots where we will probably have subjects somewhat close to the screen.
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#4 John Sprung

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Posted 23 May 2008 - 03:27 PM

RP isn't done much any more. In fact, it was pretty much gone before xenon. The ones I've seen still had carbon arc lamps. In the old days, they'd use the same Simplex or Century machines as a theater, only without the shutter, and driven by selsyn motors slaved to the camera. The setup trick was to phase the projectors to pull down during the camera's pulldown time. If you do this with a mirror reflex camera, you want to see the projection pulldown in the finder, which means it's not going on the film.

The timing issue is that a projector pulls down in 90 degrees, displays the frame for 90, then the interrupt blade blacks the screen for 90 and the frame is displayed again for 90 degrees. This gives you 48 flashes of light per second rather than 24, which is necessary to eliminate flicker. The camera exposes the film for about 180 degrees, some are 172 and similar numbers. So, to have consistent light from the screen to the film, you have to pull the shutter. The easiest ones are the early Simplex standards, because the shutter is outboard of the lens. You just loosen the setscrew, and pull it off.

BTW, have at least three prints of the plate. You'll want to be able to have someone rewind one while you're shooting with another, and a backup in case a print gets damaged.


-- J.S.
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#5 Albert Smith

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Posted 28 May 2008 - 09:19 PM

RP isn't done much any more. In fact, it was pretty much gone before xenon. The ones I've seen still had carbon arc lamps. In the old days, they'd use the same Simplex or Century machines as a theater, only without the shutter, and driven by selsyn motors slaved to the camera. The setup trick was to phase the projectors to pull down during the camera's pulldown time. If you do this with a mirror reflex camera, you want to see the projection pulldown in the finder, which means it's not going on the film.

The timing issue is that a projector pulls down in 90 degrees, displays the frame for 90, then the interrupt blade blacks the screen for 90 and the frame is displayed again for 90 degrees. This gives you 48 flashes of light per second rather than 24, which is necessary to eliminate flicker. The camera exposes the film for about 180 degrees, some are 172 and similar numbers. So, to have consistent light from the screen to the film, you have to pull the shutter. The easiest ones are the early Simplex standards, because the shutter is outboard of the lens. You just loosen the setscrew, and pull it off.

BTW, have at least three prints of the plate. You'll want to be able to have someone rewind one while you're shooting with another, and a backup in case a print gets damaged.


-- J.S.


thanks for the input but we will be doing this all digitally. I have been looking into powerful HD projectors,anyone have any experience with this...anyone?

the choice of rear projection is completely aesthetic too...it is supposed to look like rear projection...the projection will be telecined super 8 to HD and will probably be pulled out of focus most of the time. we will be shooting it in HD.

Edited by Jake Zalutsky, 28 May 2008 - 09:21 PM.

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#6 Bob Hayes

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Posted 30 January 2009 - 08:41 PM

I have been testing rear projection with moderate success. Here is a test I shot with a VariCam as the recording camera and as the source camera through a Panasonic 7000 projector and into Rosco Grey rear projection screen. At a distance of 20’ I got a 10’ by 3’ image. The color was a bit of as the day plate was shot in early morning blue light. I found the blacks to be a little milky. I shot wide open with a 180 degree shutter. That is kind of a 1.4 at 400 ASA. I haven’t given up on this system yet. You need a beefy HD projector and if it is a union show a projectionist.

Also it looked like I got an ocasional sync. issue like a flash frame every 20 seconds or so. I think they need to be synced together.

I'd love to get some expert advice on how to refine this technique. Is anyone using Black Rear Screen. What lenses for the projectors are you using. Source material. Examples of this technique in HD.

I have attatched a day plate and a night plate.

rear_screen_test_day.jpg

rear_screen_test_night.jpg
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#7 Ira Ratner

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Posted 31 January 2009 - 02:38 PM

I ain't no expert, but I immediately saw that the "Burger King" in the sign and on the building was horizontally flopped.

Edited by Ira Ratner, 31 January 2009 - 02:39 PM.

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#8 David Desio

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Posted 02 February 2009 - 01:19 PM

yup it is. Funny< I justgott off a music video that did some projecting. If going digital, you can record a still image onto disk but need to be able to mirror the image to project from the rear. I was crunched for time and didn't get to experiment too much with it.
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#9 Bob Hayes

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Posted 02 February 2009 - 06:22 PM

I ain't no expert, but I immediately saw that the "Burger King" in the sign and on the building was horizontally flopped.


Yes you caught me. This was a test still I took before I lit the inside of the restaurant and flipped the image. Flipping the image was easy. The real pain was when we needed to go into the menu the controls were backwards so we had to un-mirror every time we did an adjustment.
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#10 David Desio

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Posted 04 February 2009 - 10:55 AM

Here's a question about projection since we're on the topic; How'd they pull this off?

It was the inspirtation for a set up I did last weekend and I had a helluva time trying for the same effect. What I've come up with is:

a. they may have used a film projector instead of video
b. were able to really adjust the focal length of the projection lens
c. shot the footage that was to be projected in a very specific framing that would work when projected onto the second actor.
d. heavy make-up for the actor's face so it was more reflective?


Any thoughts? I'd like to try and acheive this look if only for my own personal satisfaction. The producer and director were happy with what I gave them but it wasn't the exact shot that I promised them.
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#11 David Desio

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Posted 05 February 2009 - 12:06 PM

maybe another way:

They shot the actor on green screen, then just layered in post...anyone?
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#12 Ian Choplick

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Posted 07 February 2009 - 10:09 PM

Looks like green screen for the background and film projection for the actor's face....
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#13 Francisco Lima

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Posted 08 March 2009 - 11:47 AM

Looks like green screen for the background and film projection for the actor's face....

Hi guys,

There is an interesting article on Rear Projection in the American Cinematographer Magazine April 2007 issue.
This article is availiable for subscribers only.
There´s also another article on how they used Rear Projection on GetSmart.
This article is availiable for everyone on the ASC website:
http://www.theasc.co...Smart/page1.php

Pgs 2 and 3 talk a bit about the scenes where they used Rear Projection and Pg 3 has one image of the Stage Setup with Rear Projection.

The April 2007 article called "Rear Projection Takes a Step Forward" talks about Rear Projection starting to be used once again due to the release of powerful (expensive) HD Projections 25,000 lumens and the possibility to perform realtime color correction of the plates using hardware such as the Luther box and playing back from HD decks such as HDCAM, D5, etc....

We started using it here @ TV Globo - Rio de Janeiro - in Feb. 2009 in one of our Soap Operas that has scenes in India and Dubai.
The timeframes between the shoot and the date the scenes AIR are extremely short (it may even be as short as shooting today to air tomorrow or even that same day) so using Chroma Key was not an option. And as you might imagine, going back to India and Dubai wasn´t either :)

We got some "good" results using a Panasonic DLP 10,000 projector which we decided to use due to our budget for rental.
But we´d really like to get our hand on is a 25,000 lumens projector.

You really need to reserve time for setting a really good Lighting setup that allows you to simulate shadows and/or car lights on the actors for night shots.

The quantity of car scenes in our Soap has grown a lot since we started and the time to setup lighting has shortened.
This has brought the quality down considerably.

One Question:
During a Rear Projection shoots should there be a VFX Supervisor onset?
Here we started implementing Rear Projection thru the VFX crew and included a really good VFX Sup with an excellent eye to make it work.
But now that it is going into full production I beleive it should be treated as a "special" scene shot inside a Stage were the Car is the Set and the Backdrop is a moving image....so the film crew and DP should carry it from now on.

What do you guys think?

Rgds,

Francisco Lima
VFX Tech. Sup.
TV Globo
Rio de Janeiro - Brazil
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#14 Daniel Porto

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Posted 09 March 2009 - 01:18 AM

I have been testing rear projection with moderate success.......


The only thing that stands out to me in terms of using near projection for realism is that the light that is on his face is not shining on the wall.
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#15 James Erd

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Posted 12 March 2009 - 03:54 PM

I'm not sure how it was shot, but I didn't see much that couldn't be done in post by a good compositor.
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#16 K Borowski

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Posted 12 March 2009 - 04:58 PM

Those new screen grabs have convinced me that it is still a valid technique, but I have to beg, please don't use it in a '40s film like Atonement! (Or was that front projection?

In other words, make sure the res. of your camera format is on the same level as that of the projector. (So, digitally, you wouldn't want to use a SD projector with an HD camera, unless it was for a comparatively small portion of the frame.)

In general, I find that trick phootgraphy of any kind tends to fall apart because one can never be too picky.

I'll always remember that one set from Star Trek in "Court Martial" where IDK what they were thinking, but you could see the corner of the wall where they painted and constructed the matte miniature background. Sure it's a background, but unless it is really, really, out of focus, you can't leave something obvious like that in your set if you want the viewing audience to take you seriously. . .
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