Jump to content


Photo

Need advice on front projection for feature film


  • Please log in to reply
4 replies to this topic

#1 Martin Oller

Martin Oller

    New

  • Basic Members
  • Pip
  • 1 posts
  • Director
  • Sweden

Posted 07 December 2017 - 04:43 AM

In a few years time, I'm about to realize my dream and produce a fantasy feature length film that I've been working on for the past 15 years. And I've come to be interested in using front projection for most of the sceneries, because:

 

1. Done right it looks amazing, and

 

2. The movie will be shot on very old anamorphic lenses with lots of distortion, thus making in-camera effects preferable over chroma, and

3. Considering the length of the movie, although it will be expensive to buy gigantic scotchlite backgrounds and projectors, it can make it possible to shoot most of the film in the same place, and create immersive sets for the actors that will be far cheaper than actually building full sized fantasy themed sets or shooting outdoors, and look better than greenscreen due to the unique visual style/lens distortion.

 

My idea at this point, is to create a set similar to what they did in "Oblivion" (2013). According to this article they used a total of 21 projectors and a 270 degree coverage, which is way out of budget for this project. I'm thinking 1 or 2 projectors and a flat mobile background on wheels that can be moved as needed.

maxresdefault.jpg

When I read about front projection, they always talk about shooting through a one-way mirror. I'm assuming that shooting like this is the only way to do it on smaller sets, where the distance between the talent/background is too short and you don't want to cast a shadow? I've watched some videos about front projection on youtube and I stil don't quite get the point of the mirror, other than the obvious (that the projector isn't in the way, and the above mentioned).

Or is there some other technical point that I'm missing here?

Front_projection_effect.jpg

 

Looking at the BTS picture from Oblivion, you can see the crew walking around on set being lit and everything. Are the bright spots beneath the platform the projectors themselves? It looks like they are angled straight up onto a mirror, and then cast onto the screens. I guess similar lighting could be made with a smaller, flat screen, using a camera with good light sensitivity and carefully add fill light primarily from above? (because light from the sides would reflect and destroy the projection, would it not?)

Also, any idea where I can buy these kind of massive scotchlite backgrounds? I just find clothes on Google...

 

Appriciate any advice on this, or other sources of information about modern uses of front projection in films. Thanks!


Edited by Martin Oller, 07 December 2017 - 04:46 AM.

  • 0

#2 Phil Soheili

Phil Soheili
  • Basic Members
  • PipPip
  • 46 posts
  • Cinematographer
  • Milan, Italy

Posted 07 December 2017 - 06:09 AM

another point in using the mirror is that your projected footage is at 90° perfectly.
You don't want to (at least most of the times) see perspective distortion in the background images.

If you have a tilt/shift lens or other means to control the perspective on your projector AND if you can manage not to have your actors and buildings cast shadows on the backdrop you might give it a try. Test it.

But from my experience of some decades (!) ago:
I don't think the image above is actually front-pro. To me it looks like a painting.
Front-pro was projected on a 400% (or better) reflective silvery foil.
The image could actually be seen ONLY in the camera's viewfinder because the
ambient light during prep. would kill the image. Ambient light is high in the pic. as

you can tell by the shadow in the unequally lit seamless background (in the curve)

Maybe things have changed...
;)

 

Good luck!


Edited by Phil Soheili, 07 December 2017 - 06:24 AM.

  • 0

#3 Phil Soheili

Phil Soheili
  • Basic Members
  • PipPip
  • 46 posts
  • Cinematographer
  • Milan, Italy

Posted 07 December 2017 - 06:31 AM

Ah, ok!
I just saw the bts.
It's projected but not in "front-pro" process as in your "diagram".

Maybe they call this process front-projection too, I thought it refers to the mirror system only.

Cheers.


  • 0

#4 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 19769 posts
  • Cinematographer
  • Los Angeles

Posted 07 December 2017 - 12:53 PM

There are two types of front projection -- what "Oblivion" did was just the opposite of rear-projection, they projected the images onto a white screen like in a movie theater.  In this case, the projector has to be hitting the screen from an angle to be in a position to be off-camera, and the screen has to be large enough and far back enough so that the angle of projection isn't too far off to one side, the projector being behind the set and actors hidden somewhere.

 

The more advanced form of front-projection first used on "2001" involves a screen made up of 3M Scotchlite and a projector lined up with the optical axis of the camera lens so that the projected image travels straight out from the lens and any foreground actor blocks their own shadow on the screen, and what gets reflected back is very bright.

 

Besides the off-angle of the projection in the case of "Oblivion", the other issue is the light levels -- those scenes for "Oblivion" were shot around an T/1.4 on Master Primes on a Sony F65 camera, I assume rated above 800 ASA.

 

The brightness of both approaches depends on the lumens output of the projector but the 3M Scotchlite approach will give you more output back to the camera (which was useful in the days of slow film stock.) One of the problems with this approach though is that it is hard to move the camera around, it's nearly always a lock-off because of the alignment of the mirror to the projector, unless built all as one unit as in the Zoptic process used for the flying scenes in "Superman: The Movie".


  • 0

#5 Simon Wyss

Simon Wyss
  • Basic Members
  • PipPipPipPip
  • 1416 posts
  • Other
  • Basel, Switzerland

Posted 07 December 2017 - 01:24 PM

I strongly advise you read the corresponding pages of

 

Motion Picture Camera Techniques by David W. Samuelson.

 

I have a copy of the second edition with me.

ISBN 0-240-51247-2. Check libraries or bookstores.


  • 0


Abel Cine

Technodolly

Willys Widgets

rebotnix Technologies

The Slider

FJS International, LLC

Opal

Tai Audio

Media Blackout - Custom Cables and AKS

Wooden Camera

CineLab

Gamma Ray Digital Inc

Rig Wheels Passport

Paralinx LLC

Visual Products

Ritter Battery

CineTape

Glidecam

Broadcast Solutions Inc

Metropolis Post

Aerial Filmworks

Wooden Camera

rebotnix Technologies

Ritter Battery

FJS International, LLC

Abel Cine

Aerial Filmworks

Willys Widgets

The Slider

Rig Wheels Passport

Media Blackout - Custom Cables and AKS

Metropolis Post

Technodolly

Visual Products

Opal

Broadcast Solutions Inc

CineTape

Paralinx LLC

Glidecam

Tai Audio

CineLab

Gamma Ray Digital Inc