Originally Posted by Gotchaa
That makes sense, so cylindrical lenses are more flexible and accurate. So what will be interesting is too see how the DC-1's sweet spot compares with the ISCO's at the same range, that would be a good test.
To make that happen, Panamorph would need to disclose the "sweet spot" so that the tester can make sure the lens is positioned at the correct distance from the screen. See, this is now different to the traditional TR though that still applies.
So assuming someone could acquire both the DC1 and the ISCO III and set them up at the "sweet spot" the DCI requires, there then comes the point of the optical design - prisms Vs cylindrical lenses.
There are three main types of distortions - Chromatic Aberration, Astigmatism and Grid Distortion.
CA is the most offensive and seemly the easiest to correct for - two glass types with different RI (cemented) have been used for years.
Astigmatism is the next and should the DC1 be placed at the "sweet spot" should produce an image with identical sharpness to the ISCO III.
Which leads us to Grid and geometry distortions. A lens like the ISCO III has curved surfaces and these surfaces are not a single radius. This is done to correct for geometric errors as the light is magnified. In other words, even though the lens is designed to be a 1.33x HE, at the edges the image could be 1.42x.
The limit to flat faces on a prisms means that GD can not be corrected for. I believe it is possible to design a prism that has a curved face so that it does not suffer this.
GD can also be corrected by using a curved screen.