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-   -   3D and Lighting (https://www.dvinfo.net/forum/photon-management/531659-3d-lighting.html)

Bruce Dempsey April 19th, 2016 07:11 AM

3D and Lighting
New sideline to my main event video effort is 3D model production.
The capture phase requires the similtaneous triggering of a bunch (32 at this point and maybe more) of still cameras which are positioned in 3 rings 360 degrees around the standing human subject, Top ring about eye level mid ring about navel level and one down just above the ankle level . (hopefully this will be enough)
I need flat light with no shadows (none at all as shadows will just produce a hole in the 3d mesh.
It needs Lotsa light (nothing subtle and artistic) No shadows under the brow, nose, chin, or anywhere, The iso needs to be 100 and f166 with a fast shutter speed
So at this point I am figuring on using 3 x 800w redheads at 0 degrees, 120 degrees and 240 degrees
These will be back with the cameras about 20 feet from the subject and pointed straight at the subject.
Is that enough?

Jacques Mersereau May 1st, 2016 02:22 PM

Re: 3D and Lighting
Hmm. So, you have an object (actor(s)?) in the center of a still camera array?

Those lights you mention will cast sharp shadows, but I am wondering why you want perfect flat lighting?

And how are you planning on keeping the lights themselves out of the shots?

I would offer that you either need soft overhead light - like a powerful balloon light or a bunch of kino flo 4x4 banks might work - or even better, go outside on an overcast day or just after sunset (not sure what you want or don't want to see in the background.) That is the best and cheapest soft light. You could rig black visqueen (plastic tarp material) as the background outside = way cheaper than trying to light this inside.



Jim Michael May 1st, 2016 05:30 PM

Re: 3D and Lighting
The usual approach for a single camera would be a ring flash.

Bruce Dempsey May 2nd, 2016 05:44 AM

Re: 3D and Lighting
When I say flat lighting I mean lighting which produces no shadow at all on the group of ballerinas or posed dancer/hockey/baseball/player/.
shadows confuse the mesh algorthym and creat holes and other anomolies
I've 4 x 800w redheads almost here for the job and I'm hoping that the sharp shadow created by one will be cancelled by the others. The cameras I have purchased for the most part are shooting at iso80 so lots of light is needed to provide for a fast shutter and deep dof
Keeping the lights out of the shot has me worried and at the moment I hope to accomplish that by extending their tripods to 9' whereas the subject will be 7' and less.
Thanks for the tip on the plastic but white is recommended I think plus it will reflect light back into the scene
No doubt outside light golden hour or before ois best but so maany other problems wind rain .
4 redheads with stands were cheap about 1/50 th of theThe kino flo solution but the balloon thingy seems interesting

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