3D Light Data when filming? Need infos..


#1

I know some info of this exists somewhere… Cameras that save 3d light data when filming real life scenes, to later add this info into your CG film creations.

Does anyone have information in this?

Thank you!


#2

When you shoot, along with the clapper, you can have a 3-tone card held up for the camera to see - keep it within the general parameters of your lighting - not held in a hotspot or shadow.

The 3 tones are black, middle grey, and white - this is information that only needs to be on 1 frame for a compositor or 3D team to use for lighting information - where your black, mid-tones and highlights will go so you create all your elements, or color correct introduced elements (photographed objects to be nestled into the scenery, etc.) so that they match your main plate. That way once a grading is done for the finished movie everything will hopefully be the same contrast, color, etc., and be seamless.

I don’t know about a “camera” that records this data, but when you get the shots back/transfered/captured you can bring up your Levels and get your measurements of the white and black and work out the middle greys.

If it’s a matter of literally THIS light coming from THIS direction, and THAT light coming from THAT direction - get the lighting diagram from the DP. If the DP didn’t plan on MAKING one, let he/she know you’ll need it for the 3D elements.

Hope this helps-
-Lew :wink:


#3

Also shoot a frame of a mirrored ball to reproduce the lighting in the scene for the cg.


#4

You can use a spheronvr camera. www.spheronvr.com
Either you buy or rent one. Rent is €1000/day + operator.

There are cheeper ways of doing this to:
Use a cromeball or use a full-size DSLR camera with sigma 8mm lens.

This is usually “good enough” however for safe/professional result use the spheronvr camera.

Also google Paul Debevec for more information about HDRI and light techniques.

Good luck with your filming!


#5

A beginner’s tip for shooting chrome spheres for HDRI photos:

When you shoot your multiple exposures, you have to go really low, so low that the brightest light source starts to drop out of its burned-out whiteness. That way you’re sure to record the differences in light strength that you need to replicate the lighting in CG.

  • Jonas

#6

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