Background projecting

[Mikko]

How to project an image with slide (or S8) projector to the background of an actor? I wanna light the actor with key and fill lights (and mayby some back light to the hair) and I'm afraid that the image on background is gonna be too dim. The background image needs to be bright with rich colors (like kodachrome or 50's technicolor films)
What should I do?
No blue screen!

Mikko

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[MovieStuff]

<BLOCKQUOTE><font size="1" face="Courier, Arial">quote:</font><HR>Originally posted by Mikko:
How to project an image with slide (or S8) projector to the background of an actor? I wanna light the actor with key and fill lights (and mayby some back light to the hair) and I'm afraid that the image on background is gonna be too dim. The background image needs to be bright with rich colors (like kodachrome or 50's technicolor films)
What should I do?
No blue screen!

Mikko
<HR></BLOCKQUOTE>

Hi, Mikko!

Well, you've pretty much answered your own question. If you don't use bluescreen, then you're pretty much out of luck, I'm afraid. The problems are many: The image won't be bright enough, the projector and camera will be out of synch so the image will pulse, etc.

However, there may some work-arounds. I need more information.

A) Is your actor going to pass in front of the image? Does he/she HAVE to?

B) Is the camera going to be locked off, hand held or moving on a dolly?

C) How big a projection do you need? A small window? Head to toe?

D) How long is the shot? A couple of seconds? Half a minute?

E) Will the projection extend to the edges of the frame or will the edges dissappear behind set pieces?

If you can give me these answers, I might be able to help you figure out a way to make it work without bluescreen.



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Roger Evans
MovieStuff
http://www.afterimagephoto.tv/moviestuff.html

[Mikko]

A) Yes. Standing in the front of the image too.

B) Tripod. (also tripod + wheels)

C) Head to toe OR smaller. head to belly.

D) 10 sec. or more

E) To the edges of frame, no other set than actor & screen.

Slide projector is good for this purpose. No moving image needed on the background.

F) Thanks : )

Mikko

ps. If I use bluescreen (which I don't have) what can I use for it? Just some blue canvas? Or green?
This scene I could do with bluescreen 'cos I'm editing this one with video, but normaly I edit my films as a film and this would be impossible. That's why I wanna learn how to do this without the freakin' bluescreen!

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[MovieStuff]

Hi Mikko!

Well using a slide projector is MUCH more managable. You are still going to have a problem with image intensity, however, there are things you can do. If you are using a Kodak slide projector, then there are modules you can put in called "hot shots" which are brighter bulbs than normal. Also, you can have several copies of the same slide and use three projectors all aligned on the same screen. In the old days of Technicolor, they did that very thing with three movie projectors to get a bright enough image for rear projection!

What are you using for your rear screen? Rear screen material that size isn't cheap.

If the background doesn't have to move, here is a more pratical alternative. Go to your local copy place that can make 12x18 inch color copies. They almost all have the capability to take your original and break it up into dozens of overlapping 12x18 segments that you could spraymount onto a large board or tape to the wall with double sided tape. It works pretty good and I have done this a couple of times for some quick blow ups. If you do, make sure that you start at the top and over lap with the edges facing up or the same direction as the key light in the photo. This will prevent the edges from casting shadows.

Good luck!


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Roger Evans
MovieStuff
http://www.afterimagephoto.tv/moviestuff.html

[mattias]

> If I use bluescreen (which I don't have) what can I use for it? Just some blue canvas? Or green?

depends on your keying soft/hardware. but basically yes, any color will do, red or whatever as well (pick one that's not in your foreground), but it has to be rather saturated and you'll have to light it very evenly and to about the same stop as your foreground.

one more thing: i'd recommend putting a few "motion control plusses" on the screen to detect and correct for the sometimes bad registration of super 8 footage. if the plate will be super 8 as well, i'd make sure there was a few static references in there as well. thanks a lot to whoever it was who suggested this stabilizing method to me some time ago. it more or less saved my life recently...

by the way, i've never tried front projection, but wouldn't that be the normal old school way of solving this problem?

/matt

[MovieStuff]

<BLOCKQUOTE><font size="1" face="Courier, Arial">quote:</font><HR>Originally posted by mattias:

by the way, i've never tried front projection, but wouldn't that be the normal old school way of solving this problem?
/matt<HR></BLOCKQUOTE>

Well, sure, if you've got $100 per square yard to spend on front projection material! I've used it in the past and it works pretty good, but you need a nodal point pan and tilt head if you want to follow the action or you'll go off axis. Hand held or dolly shots would be out of the question, so I tried to stay within Mikko's technical and (assumed) budgetary constraints.



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Roger Evans
MovieStuff
http://www.afterimagephoto.tv/moviestuff.html

[Shenan]

Long post, but this is something that really intrigues me.

I have seen it done before, and it worked almost flawlessly. It was in a 16mm film I saw in class. It used a slide projector onto a rear projection screen. The background image was a night view of a city, with buildings, etc. Imagine the characters were on top of a skyscraper at night looking out at other skyscrapers around them. IF I recall correctly, my teacher who was the DP in the movie said that they used a large fresnel screen for the rear projection, but don't quote me on it.

BTW, I said "almost" because they used a blinking LED to pass for a blinking light on top of a building and it was just too big and bright and threw the illusion off. If it hadn't been for the LED I probably wouldn't have noticed. Also, if you think about it, the nature of the background image probably helped the illusion quite a bit. If it had been a bright image of sand dunes in the Sahara desert I don't think it would have worked.

What materials/techniques did they use in all the movies from the 40s and 50s that used rear-projection effects extensively (i.e. characters driving a car - see also Airplane )? It couldn't have been that complicated, could it?

Shenan

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[This message has been edited by Shenan (edited November 06, 2001).]

[Matt Pacini]

I originally experimented with some of this in Lost Tribes, and abandoned it, because I couldn't get the background even NEAR bright enough!
Remember, we're talking Super 8 here!

Matt Pacini

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[Mikko]

Thanks for all!
I'm going to ask from travel agencys if they have some old big posters that I could use as a background.

M

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