Rear vs. front anamorphic element

[Jarin Blaschke]

Do anamorphic lenses with the 'squeezing' element placed in the back have the same 'ovular' distortion of background elements as a lens with the element in front? For example, using a rear-mounted anamorphic lens with a night exterior, would the lights in the background appear as circles (like a spherical lens) or vertical ovals, (like an anamorphic lens with the anamorphic element placed in front)? If there is such a visual difference according to where the anamorphic element is placed, it seems that a set of anamorphic primes (front) may have problems truly matching the zoom (rear), even if the two are colorand performance matched.

 

-Jarin

[David Mullen ASC]

No, rear-mounted anamorphic elements do not to create the oval-shaped lights in the background -- but on the longer lenses, you instead get SQUARE-shaped lights, which is really odd-looking.

 

Wide-angle lenses tend to not have room in the back for an anamorphic element, plus back focus is too critical with those lenses to stick another element back there. Plus I suspect it is easier to make a sharper anamorphic element if it is large (for the front) than tiny (for the rear.)

[Jarin Blaschke]

Hmm, which lenses in particular render these squares? So the smallest passage for light through the lens is actually square?