Minimum number of cameras to reconstruct a surface?

[Mr_Curious]

What is the minimum number of cameras needed to reconstruct a surface using DSLR cameras?

Logic tells me the answer would be 2... but practically speaking, how many are needed at MINIMUM?

For example, say I have a person sitting in the center of a room.  Now lets assume that I have 2 DSLR cameras with 50mm lenses placed some distance away (let's assume 1 meter) both at 45 degree angles to the subject and aimed and focused at the subjects head.

Would 2 cameras be enough to reconstruct the surface in the "real world" or would more cameras be needed?  If more are required, how many would I need?

BTW... I would test this myself, but I only have a single DSLR at the moment. Hopefully, I can get more, but I'm trying to figure out the minimum number needed.

Greetings,

Mr. Curious

[Wishgranter]

for reconstruction, if are two photos, you need OVERLAP, if is overlap 10 %, can be reconstructed jut 10 % if have 90 % overlap then can be reconstructed 90 % from 2 photos, therefore for a face im assuming at least 3 cameras are need..... Here is importaint what wil lbe done with that data, a  closeups of face or whole body Try to start with 550D and good lenses - 18 Mpix is enought. If shootet from 1m then you get "precision" under 0,2 mm   

[Mr_Curious]

for reconstruction, if are two photos, you need OVERLAP, if is overlap 10 %, can be reconstructed jut 10 % if have 90 % overlap then can be reconstructed 90 % from 2 photos, therefore for a face im assuming at least 3 cameras are need..... Here is importaint what wil lbe done with that data, a  closeups of face or whole body Try to start with 550D and good lenses - 18 Mpix is enought. If shootet from 1m then you get "precision" under 0,2 mm   

I understand!

Thank you for the explanation and advice.

Time to buy a few cameras!

Greetings,

Mr. Curious