mumping in anamorphic lenses

[Jason West]

Hi,

Can anybody explain the mumping of anamorphic lenses how it actually occurs on a elemental level, and how one avoids it.How well does the anti mumping in the newer g series lenses work.

thanks,

jason West

[Jean-Louis Seguin]

Hi,

Can anybody explain the mumping of anamorphic lenses how it actually occurs on a elemental level, and how one avoids it.How well does the anti mumping in the newer g series lenses work.

thanks,

jason West

Edited March 12, 2010 by Jean-Louis Seguin

[Phil Rhodes]

Now, call me a Johnny-come-lately part-timing not-knower, but - "mumping"?

[Brian Drysdale]

I thought the mumps (a problem with the Cinemascope lenses) had been more or less sorted with the Panavision lenses in the 1960s. Here's one explanation:

 

http://en.wikipedia.org/wiki/CinemaScope

Edited March 12, 2010 by Brian Drysdale

[David Mullen ASC]

I thought the mumps (a problem with the Cinemascope lenses) had been more or less sorted with the Panavision lenses in the 1960s. Here's one explanation:

 

http://en.wikipedia.org/wiki/CinemaScope

 

The problem was always exaggerated by Panavision to sell their lenses over B&L CinemaScope lenses, but it actually existed... basically the squeeze ratio dropped off as you focused closer, but the unsqueezing was a constant 2X in movie theaters, so the net result was that close-ups looked "fat". Panavision basically moved the problem off of the in-focus area and into the out-of-focus area... which now get too much of a squeeze as you focus closer, but the subject remains the correct squeeze, hence why out of focus lights become vertical ovals in anamorphic shots.

 

But there is a bit of a slippery slope in that regards and I've noticed that occasionally faces look like they have the wrong squeeze to them, but it could be just that the focus is slightly off.

 

You see the stretched background here in this frame:

 

On the original negative, it would look like this. You see basically that the background is over-squeezed, more than 2X, so it still looks skinny when unsqueezed:

[Oliver Christoph Kochs]

Could it be that the human eye is used to round bokeh effects and tries to interpret them as a circle.

Thus the optical effect makes the face wider.

Kind of like a skinny person wearing a horizontally striped shirt would look - let's exaggerate - fat.

[Jason West]

hi,

thamnks for the answers,

I also had not heard of mumping until recently whilst reading panavisions literature on the G-series, where on page two it specifically says "the lenses utilize panavisions patented anti-mumping technology" sounds like something new to me not something that was eradicated in the 1960's.it goes on to say there is no "hump" in the gear set, so the lenses maintain their cylindrical profile , any offers on how this works.

[Brian Drysdale]

hi,

thamnks for the answers,

I also had not heard of mumping until recently whilst reading panavisions literature on the G-series, where on page two it specifically says "the lenses utilize panavisions patented anti-mumping technology" sounds like something new to me not something that was eradicated in the 1960's.it goes on to say there is no "hump" in the gear set, so the lenses maintain their cylindrical profile , any offers on how this works.

 

Reading that section, I've a feeling the "hump" may be a bump on the lens casing that housed the gears in the earlier lenses, but this is no longer there on the G series.

 

I'm not sure if this is the patent involved (perhaps bought by Panavision), but quickly scanning through, it does seem to address the "mump" issue:

 

http://www.freepatentsonline.com/2890622.pdf