What happens when you put a rear anamorphic adapter to a front anamorphic lens?

[Edith blazek]

Could someone tell me this? Has anyone done this? What is the effect?

[David Mullen ASC]

If the front anamorphic is 2X and the rear anamorphic is 2X, that's a 4X squeeze! Quite a widescreen image once unsqueezed... even if your sensor area used is a square, that's a 4.00 : 1 image once unsqueezed...

A rear anamorphic doesn't add much of a look per se.

[Edith blazek]

1 hour ago, David Mullen ASC said:

If the front anamorphic is 2X and the rear anamorphic is 2X, that's a 4X squeeze! Quite a widescreen image once unsqueezed... even if your sensor area used is a square, that's a 4.00 : 1 image once unsqueezed...

A rear anamorphic doesn't add much of a look per se.

So the squeeze is compounding? Is I were to set the rear anamorphic 90 degrees in the mount, could I cancel our the stretch?

[Brian Drysdale]

What is the effect or look that you're trying to achieve?

[Edith blazek]

40 minutes ago, Brian Drysdale said:

What is the effect or look that you're trying to achieve?

Im just curious but I do remember hearing about how the ultra vista lenses from panavision have rear anamorphic optics to partially cancel the squeeze of the front anamorphic optics to create a 1.65x lens and that piqued my curiosity.

[David Mullen ASC]

I suppose that makes sense if you really want the look of a 2X squeeze but without all the squeezing, but that would be a specially-made rear anamorphic. The trouble with cancelling the squeeze altogether with a 2X rear anamorphic I think becomes that you've essentially desqueezed the image into a very widescreen one, so what are you capturing? One cropped back down on the sides to the sensor dimensions? One that retains more width but has fall-off along the top & bottom, sort of a fuzzy letterbox? I guess it all depends on the image projection.

[Dom Jaeger]

9 hours ago, Edith blazek said:

Im just curious but I do remember hearing about how the ultra vista lenses from panavision have rear anamorphic optics to partially cancel the squeeze of the front anamorphic optics to create a 1.65x lens and that piqued my curiosity.

Actually quite a few anamorphic designs use anamorphic cylinders set at 90 degrees to control the squeeze, or attempt to minimise anamorphic breathing. 

The system used in Panavision anamorphics to control mumping (the variation in squeeze that happens as you go to close focus) is essentially two counter rotating anamorphic elements, of very low power, that reduce their combined squeeze the closer they rotate to 90 degrees, at which point they cancel each other out.

There is also an anamorphic front attachment that mimics the horizontal anamorphic flare but without introducing a squeeze which uses the same principle.

Putting a rear anamorphic adapter at 90 degrees on an anamorphic lens would indeed cancel the squeeze, while keeping the flare behaviour and some of the optical falloff of the anamorphic. But you would lose a lot of light and degrade the image, since those rear adapters always do that a bit. They work like a doubler, but only in the vertical axis (when normally fitted). So you would also end up with a cropped image, since the adapter magnifies, then crops that axis.