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Lighting a night car scene on chroma

Ankur Ahuja
 

Hi All, 

I'm due to shoot a scene set inside a moving car on a chroma stage. We would like to simulate realistic lighting with passing streetlights but it's a vfx heavy scene, hence the same lighting needs to be repeated with some focus on precision for multiple plates which rules out manually rotating lights option. 
We have done some tests with led screens flanking either side of the car, playing back footage of passing streetlights. The quality of light works but it seems too sidelit for a streetlight. The cost of rigging the screens on top facing downards may be prohibitive. 
I would really appreciate an experienced opinion on this, or other ideas. 

Thanks in advance! 

Ankur Ahuja
Cinematographer
Delhi/Mumbai 

 

The system VER had at the BSC show this year was amazing.  LED screens top, back and sides.   Personally not used it in real life but it looked utterly convincing..

Michael Sanders
London Based DP.

+ 44 (0) 7976 269818




On 31 Jul 2018, at 15:33, ahuja.ankur@... wrote:

We have done some tests with led screens flanking either side of the car, playing back footage of passing streetlights. The quality of light works but it seems too sidelit for a streetlight. The cost of rigging the screens on top facing downards may be prohibitive. 
I would really appreciate an experienced opinion on this, or other ideas. 

Mark Kenfield
 

IOn 31 Jul 2018, at 15:33, ahuja.ankur@... wrote:

We have done some tests with led screens flanking either side of the car, playing back footage of passing streetlights. The quality of light works but it seems too sidelit for a streetlight. The cost of rigging the screens on top facing downards may be prohibitive. 
I would really appreciate an experienced opinion on this, or other ideas. 


Have you tried bringing in mirrors to catch the peripheral light projected by the screens, and bounce it back into the car from a more frontal angle? 

Cheers,

Mark Kenfield 
Cinematographer 
Melbourne 

0400 044 500

Fred Young
 

Could you switch from video screens to something like a color force LED light? They would probably be easier to rig where you’d need them and using a media server you could playback your footage through the lights. 

Fred Young
Lighting and Camera for Motion Pictures
828.231.9080

On Jul 31, 2018, at 11:21, Mark Kenfield <mark@...> wrote:

IOn 31 Jul 2018, at 15:33, ahuja.ankur@... wrote:

We have done some tests with led screens flanking either side of the car, playing back footage of passing streetlights. The quality of light works but it seems too sidelit for a streetlight. The cost of rigging the screens on top facing downards may be prohibitive. 
I would really appreciate an experienced opinion on this, or other ideas. 


Have you tried bringing in mirrors to catch the peripheral light projected by the screens, and bounce it back into the car from a more frontal angle? 

Cheers,

Mark Kenfield 
Cinematographer 
Melbourne 

0400 044 500

Mark Weingartner, ASC
 

Here is an old-school (or relatively old school) solution I have used with good effect:

If you line up a number of tungsten fixtures fairly close together you can use a dimmer board (lighting desk) to build a chase sequence from light to light

If you stretch very light diffusion closer to the car than the lights it will blend the beams a little so you dont get a hard jerky shadow from light to light

I have tried this where each cue has two adjacent lights on - so cue 1 is lights one and two, cue 2 is lights two and three, cue 3 is lights three and four etc -
You can set these with autofollow so they run at a pre-determined speed and some lighting desks will integrate with time code or another master clock,

It’s a lot of work to set up but it is relatively low-tech rigging -

You can have two sets of lights chasing along the line if the streetlights are closely spaced

The hard part will be syncing the actors’ dialog to the sequence… syncing the plates to the sequence not so hard… you can have all the lights flash at the beginning for a sync point at the start of your sequence


Mark Weingartner, ASC
Director of Photography
inclined towards Visual Effects



+1 818 970 6833 mobile
vfxmark@...
skype: vfxmark

Steve Oakley
 

so you got me thinking… why not use Ableton ( or lighting sequencing app ) + USB->DMX controller + DMX connected LED’s ? you can run sequences all day long exactly the same, with TC. there are lighting boards that can be programmed in a similar fashion to run sequences. you could set up a 8 count click track to get the actors into their timing of the sequence and then let it run.

Steve Oakley
DP / Editor / Colorist / VFX Artist
Madison & Milwaukee WI
920 544 2230

Jonathon Sendall
 

Hi Ahuja

I've been approaching the same problem but decided to try and test the same principal as the
sky house in Oblivion. That means going out and shooting either four sided or three sided shots
with a simple car rig of some sort then project on different sides of the car giving highly realistic
lighting data and source. You can either back project or front project (front can be projected
from below set to a splitter at 45 degree onto your screens and perspective corrected in
software or projector menu). You can get some very bright projectors and the screens don't
have to be far from your car passengers to make them look well lit. I prefer this to chroma for
the simplicity of not having to deal with green spill and multiple reflections and makign the lighting
look real to the situation.

Passing headlights lighting faces and the interior however is another matter.

My lack of knowledge is in the accurate stitching together of multi projectors and have asked
this question on the VFX forum.

Be nice to know where you go with it finally.

Jonathon Sendall
DP, London UK

Jonathon Sendall
 

How ever it just occured to me that if you took the head on camera that took footage for the
projection, blurred it to some degree and then projected at the car and passengers itself you would
get sync between general lighting from the screen projected footage AND footage being projected
blurred into the car from the front. Beware of pixelation on right angled surfaces to the blurred projector. To prevent that blur in some way after the image has exited the lens.

Jonathon Sendall
DP, London UK

Ankur Ahuja
 

We did try a programmed Skypanel reflecting off a bounce board, worked quite well, haven't tried a mirrror though. 

Ankur Ahuja
Cinematographer 
Delhi/Mumbai


On Tue, 31 Jul 2018, 7:21 p.m. Mark Kenfield, <mark@...> wrote:
IOn 31 Jul 2018, at 15:33, ahuja.ankur@... wrote:

We have done some tests with led screens flanking either side of the car, playing back footage of passing streetlights. The quality of light works but it seems too sidelit for a streetlight. The cost of rigging the screens on top facing downards may be prohibitive. 
I would really appreciate an experienced opinion on this, or other ideas. 


Have you tried bringing in mirrors to catch the peripheral light projected by the screens, and bounce it back into the car from a more frontal angle? 

Cheers,

Mark Kenfield 
Cinematographer 
Melbourne 

0400 044 500

Ankur Ahuja
 

Thanks all for the ideas.
Rigging lights overhead on a dimmer board is one way, then there is the choice of lights, sequencing them and syncing them with actors' dialogues with a cueing system. However, using led screens to light up seems like it should be simple and realistic. 
I'm wondering if everyone is using the same approach, shooting plates and rigging screens overhead to match the light, or am I missing a crucial step?

Projection,too, is an interesting idea that's worth some research and testing.

On Tue, 31 Jul 2018, 8:32 p.m. Jonathon Sendall, <jpsendall@...> wrote:
How ever it just occured to me that if you took the head on camera that took footage for the
projection, blurred it to some degree and then projected at the car and passengers itself you would
get sync between general lighting from the screen projected footage AND footage being projected
blurred into the car from the front. Beware of pixelation on right angled surfaces to the blurred projector. To prevent that blur in some way after the image has exited the lens.

Jonathon Sendall
DP, London UK