[lotsofmangos]

I've commented this before, but Amazon's white background patent stresses that it achieves a seamless background with no need for post-processing.

There is a very good reason for this.

When this technique was developed, post-processing was done with a wand in a darkroom and electronic computers were yet to be built.

edit - actually, if you replace the camera with an audience, the effect predates photography. Infinity cycloramas being a popular set building technique in 19th century German theatre.