[MF3D.FORUM:575] Mirror Images

[Tom Hubin <thubin@xxxxxxxxx>]

Lee Moore wrote:
> 
> Many of the 1950's era 3-D movies were made by taking two conventional
> movie cameras (eg. Mitchell) and pointing them at each other.
> Between the lenses were placed two front surface mirrors to give
> the desired seperation.
> 
>  --------         / \        --------
> | camera |==     /   \    ==| camera |
>  --------       /     \      --------
> 
> Ray Zone gave a presentation on 50's stereo movies to the SCSC meeting last week.
> 
> Lee

Hello Lee,

That's pretty clever. I like it. But there is a drawback for the
purists. This will produce a mirror image in each camera. 

That means flipping your slides over. The purists will say that the
emulsion is now on the wrong side of the slide and that the projected
image won't be as sharp.

For prints you need to tell the shop to flip the negative over before
printing. As with slides, the emulsion is on the wrong side and the
printed image won't be as sharp.

An odd number of mirrors per camera, regardless of orientation, will
produce a mirror image. An even number of mirrors per camera will
produce a normal image.

I do not do photography or projection normally. I'm just an optical
engineer who is curious about stereo. So you will have to rely on the
photographers to say how the image quality is effected when the emulsion
is on the wrong side. 

Tom Hubin
thubin@xxxxxxxxx