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Barrel Distortion


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#1 Mathew Collins

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Posted 01 March 2016 - 06:06 AM

Hi,

 

I was watching Alien(1979). I am referring to a subjective shot of the character played by Harry Dean Stanton while searching for a Alien. I could see very minimal Barrel Distortion at the edges of the door. But in many films which shot in anamorphic, i have observed easily noticeable distortion.

 

How could have DoP Derek Vanlint reduced this?

 

And there is no closeup of Harry Dean Stanton preceded or followed by this subjective shot. Would it purposefully eliminated?

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Edited by Mathew Collins, 01 March 2016 - 06:12 AM.

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#2 David Mullen ASC

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Posted 01 March 2016 - 11:13 AM

That shot has barrel distortion, could have even been the 35mm C-Series anamorphic instead of the 40mm.

 

A lot of the movie used longer primes and anamorphic zooms, which is part of Scott's stye, so barrel distortion would not come into play.  There aren't a lot of super wide-angle shots and the few there are don't necessarily have a lot of strait vertical columns or lines to show off the barrel distortion.


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#3 Mathew Collins

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Posted 02 March 2016 - 10:28 PM

That shot has barrel distortion, could have even been the 35mm C-Series anamorphic instead of the 40mm.

 

A lot of the movie used longer primes and anamorphic zooms, which is part of Scott's stye, so barrel distortion would not come into play.  There aren't a lot of super wide-angle shots and the few there are don't necessarily have a lot of strait vertical columns or lines to show off the barrel distortion.

 

>That shot has barrel distortion, could have even been the 35mm C-Series anamorphic instead of the 40mm.

 

Thank you David.

 

How did you analyzed that this shot used 40mm?


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#4 David Mullen ASC

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Posted 02 March 2016 - 10:56 PM

40mm is the most commonly used wide-angle lens in anamorphic.
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#5 Carl Looper

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Posted 02 March 2016 - 10:57 PM

If by "doors" one is referring to the verticals in the centre of the screen, such won't exhibit the same amount of distortion as that exhibited towards the edges of the screen. This is the case in all examples of barrel distortion - not just this particular one.

 

For example, in this one we see lines at the centre of the screen (in the centre of the back wall) are less curved than those out towards the edges.

 

bowman%20mid%20room.jpg

 

 

A better question might be why (or how) the shot below has next to no barrel distortion ?

 

 

2001_2.jpg

 

 

C


Edited by Carl Looper, 02 March 2016 - 11:08 PM.

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#6 cole t parzenn

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Posted 02 March 2016 - 11:32 PM

It was a different lens?


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#7 Carl Looper

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Posted 02 March 2016 - 11:56 PM

Indeed but what kind of lens I wouldn't know. It's certainly not by means of any digital de-distortion, given the era in which it was done.

 

This is a wide angle shot I did on 16mm Tri-X, using a 5.5mm wide-angle adapter for an otherwise 10mm lens. No digital de-distortion. The minimal distortion is purely a function of the lens optics.

 

 

WideLens2.jpg


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#8 cole t parzenn

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Posted 02 March 2016 - 11:58 PM

Presumably, one of the wider Panavision Super 70 lenses. There's a fair bit of vignetting...


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#9 Mark Dunn

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Posted 03 March 2016 - 08:02 AM

The first one was shot with the Dimension-150 bugeye- there are production stills showing it on the set.The second one wasn't.


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#10 Doug Palmer

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Posted 03 March 2016 - 01:22 PM

A better question might be why (or how) the shot below has next to no barrel distortion ?

 

 

 

 

 

 

The first distorted shot comes soon after Bowman's  mind-blowing arrival, and realising he has aged,  and puts us in his mind more so than a 'normal' perspective shot might have done.   The other shot is actually taken some distance further back in the bedroom location, so did not need a bug-eye lens. And Kubrick was probably avoiding any suspicion of distortion that might have occurred on the monolith itself.  But it's interesting there is no distortion elsewhere considering that the lens is pretty wide.


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#11 Freya Black

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Posted 03 March 2016 - 02:53 PM

Oddly that set looks really 80's.

...but its 1968 and they havn't even landed on the moon or gone decimal yet.


Edited by Freya Black, 03 March 2016 - 03:02 PM.

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