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Lens used in 'Magnolia'


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#1 Jonny Brady

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Posted 20 March 2009 - 08:41 AM

Hi,

Watched Magnolia last night and noticed that the lens used produced a focus effect I've never seen before where everything that is out of focus is distorted vertically and as focus is pulled sharper the objects reduce in vertical size. For example glowing lights in the background will be vertically oval shaped and as focus is pulled they become circular again. Can anybody tell me what kind of lens is being used here and why this happens?

Many thanks!
JB
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#2 Alex Haspel

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Posted 20 March 2009 - 10:03 AM

anamorphic lenses produce the effect you described.
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#3 David Mullen ASC

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Posted 20 March 2009 - 10:51 AM

Particularly, lenses using front anamorphic elements (usually primes), as opposed to rear-adapted anamorphics (often zooms and telephotos, macros, etc.)

I'd read John Hora's article on anamorphic history in the ASC Manual.

The basic gist is that CinemaScope lenses, and current anamorphic lenses, have a 2X horizontal compression and anamorphic projector lenses have a 2X horizontal expansion. However, as you pull focus, the changing distance between elements can cause a change in the degree of the squeezing effect... but the amount of expansion during projection is a constant 2X.

In the early days of CinemaScope as you focused closer, the amount of compression would drop off (less than a 2X squeeze) making faces in close-up (often closer to the lens than an object in a wide shot) look fat once they were expanded by 2X in the theaters - called "anamorphic mumps". Panavision solved this problem by a change in the cams of the lens elements, so that rather than have the in-focus subject get too little squeezing as you focused closer and closer... the out-of-focus background now gets too much squeezing compared to the in-focus subject. So even though the expansion in the theater is a constant 2X, the out-of-focus backgrounds that got more than a 2X squeeze still look vertically compressed, skinny.
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#4 Chris Keth

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Posted 21 March 2009 - 01:46 AM

That's every anamorphic lens ever. You can really notice the squeeze in the beginning of Raiders of the Lost Ark when it rack focuses from the gold idol in Belloch's hand to the tribesmen.
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#5 Leo Anthony Vale

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Posted 21 March 2009 - 01:42 PM

Panavision solved this problem by a change in the cams of the lens elements, so that rather than have the in-focus subject get too little squeezing as you focused closer and closer... the out-of-focus background now gets too much squeezing compared to the in-focus subject. So even though the expansion in the theater is a constant 2X, the out-of-focus backgrounds that got more than a 2X squeeze still look vertically compressed, skinny.


Panavision added a lens module called the variable astigmatizer, which has a positive cylindrical dioptre and a negative cylindrical dioptre rotating against each other, causing their squeeze to vary.

http://www.google.co... wallin#PPP1,M1

But the extra squeeze in the backgrounds, which effects the bokeh is due to the anamorphot having different horizontal and vertical depths of field.
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#6 Jonny Brady

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Posted 21 March 2009 - 07:23 PM

I THOUGHT it might be to do with anamorphic lenses, I mean it made sense that it would be - but since I'd never seen it before I thought maybe not...

Maybe I've watched a lot of films that weren't shot with anamorphic lenses...

Thanks a lot for your help!
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#7 Jonny Brady

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Posted 22 March 2009 - 03:24 PM

Actually - I've just remembered the reason I was sceptical about it being because of the use of an anamorphic lens - surely an anamorphic lens would stretch out-of-focus blobs of light in the background horizontally, not vertically? 'Cause won't that mean on the negative, the the light blobs will be even narrower than when they are "anamorphed" (if that's even a word)? Shouldn't they be circular on the neg and horizontally oval on the 'anamorphed' projection? Or am I getting into complex optics here...
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#8 David Mullen ASC

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Posted 22 March 2009 - 06:15 PM

'Cause won't that mean on the negative, the the light blobs will be even narrower than when they are "anamorphed" (if that's even a word)?


Yes, they are -- they are over-compressed, more than 2X, so they don't stretch back out to circles when uncompressed by 2X.

This is on the negative:
Posted Image

But this is how it looks stretched out by 2X:
Posted Image

This is also why you get red flattened horizontal rings on some older anamorphics -- the ring is due to an uncoated spherical element, which produces a circle on the negative, but it gets stretched out by 2X horizontally during projection.

And the blue horizontal line is due to the front surface of an anamorphic lens being barrel-shaped.

Posted Image
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#9 Jonny Brady

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Posted 23 March 2009 - 08:13 AM

Ahhh, very interesting... thanks a lot for your help!
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