How do projectors produce black.

[G0o5e]

Is it possible for modern day projectors to produce black on a white screen ? How is this acheived ?
I have heard some of the new 3d projectors coming out soon from epson are capable of producing a good picture in a moderately lit room.

http://www.trustedreviews.com/epson-3_Projector_review

[Alex]

They don't produce black. A bright white light next to no light tricks the eyes into seeing black - and the eyes genuinely see it as black though it's not.

[Funkstar]

The same way printers produce white, they don't

[aidanjt]

Black isn't a real colour, it's how our brain interprets a distinct lack of photon absorption by the eye. So all a projector needs to 'project' black, is to not transmit the light, in the case of a film projector, that means the film is absorbing the white light where black is to be 'projected', just as other colours are projected by the film by absorbing photons which aren't at that colour's wavelength.

The white screen merely appears black because the room is otherwise blacked out.

[mikerr]

They don't produce black. A bright white light next to no light tricks the eyes into seeing black - and the eyes genuinely see it as black though it's not.

Yep, similarly it depends on the rest of the image
e.g. The squares A and B below are the exact same colour:

[1stRaven]

Ok, that image is freaky......

[chuckskull]

Our eyes are amazingly easily tricked. I constantly amaze myself by not walking into things tbh.

http://www.youtube.com/watch?v=ORoTCBrCKIQ is my favourite.

[Fraz]

Ames' Window is another good one, although has nothing to do with the weird colour trickery of the image above

http://www.youtube.com/watch?v=tc_LqIaO2b8