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How wide is 65mm really?

65mm FOV Anamorphic Super 35 Aspect Ratio Crop

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#1 Albert James Harnois III

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Posted 18 May 2015 - 06:56 PM

So 65mm has an aspect ratio of 2.20:1, but does it give you a wider horizontal FOV like the anamorphic process does?  

 

That is, if I were to slap an 80mm lens on a 65mm camera and a 32mm lens on S35(cropped to 2.20:1) would it give me the same image in terms of spatial compression and horizontal FOV?  Or would I have to shoot on a 50mm Anamorphic lens and crop the sides?  This is all hypothetical of course-I'm just trying to get a grasp on the 65mm format so I can further appreciate the films that utilized the process.     

 

 


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#2 David Mullen ASC

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Posted 18 May 2015 - 07:38 PM

The field of view is determined by the focal length and the size of the target area.  Now with anamorphics, you essentially are doubling the normal horizontal view, so a 50mm 2X anamorphic acts like a 25mm spherical horizontally.

 

5-perf 65mm image area is 52.48mm wide.

 

4-perf 35mm anamorphic is 21.95mm wide but with an optical squeeze that doubles the field of view, so you can think of it as acting like a 43.90mm wide format with a spherical lens in terms of field of view.  This means that the focal lengths used in 35mm anamorphic photography are similar (but slightly shorter) to those used in 5-perf 65mm photography, and so are the depth of field issues, at least horizontally.

 

Super-35 is 24.89mm wide.  

 

So that's a 2.11X difference with 5-perf 65mm (divide 52.48 by 24.89).  So if you use an 80mm lens on a 5-perf 65mm camera, you'd want to use a 38mm lens on a Super-35 camera to match horizontal view.

 

It's a 1.76X difference between anamorphic and Super-35.  So to match a 38mm lens on a Super-35 camera, you'd use a 67mm anamorphic lens or that 80mm lens on the 5-perf 65mm camera.

 

The other thing to keep in mind with 5-perf 65mm is that the native shape is already widescreen -- after all, it's only one perf taller than 4-perf 35mm but twice as wide.


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#3 Albert James Harnois III

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Posted 18 May 2015 - 10:34 PM

Thank you, thank you, thank you, David.  Your examples were perfect; I can finally visualize it in my head.  


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#4 Leon Liang

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Posted 19 May 2015 - 02:31 AM

David, just a quick question: the projection aperture usually cuts off a bit from the edges of the frame, right? So even though standard 35 is 21.89mm wide, when projected on film is only about 21mm projected? Because according to good old Wikipedia, 70mm has a projection aperture of around 48mm, so I'm guessing 4mm of the 52.48mm is cut off. Does this happen with film, and if so does it also happen in digital projection?
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#5 cole t parzenn

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Posted 19 May 2015 - 05:06 PM

Super-35 is 24.89mm wide. 

 

Is this intended to be perforation to perforation? I wasn't sure I'd seen that number before, so I checked Wikipedia - interestingly, Wiki lists different numbers for the perforation to perforation gate width of S35, VV, and Technirama. (Though the difference between VV and Technirama is possibly a rounding or conversion error.)


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#6 David Mullen ASC

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Posted 19 May 2015 - 11:46 PM

David, just a quick question: the projection aperture usually cuts off a bit from the edges of the frame, right? So even though standard 35 is 21.89mm wide, when projected on film is only about 21mm projected? Because according to good old Wikipedia, 70mm has a projection aperture of around 48mm, so I'm guessing 4mm of the 52.48mm is cut off. Does this happen with film, and if so does it also happen in digital projection?

 

Standard 35mm sound projection gates are all .825" wide, which comes out to 20.955 mm.

 

70mm projection is 1.912" wide, which comes out to 48.5648 mm.

 

Digital projectors don't use gates, they show the pixel dimensions of the file.  So 2K 1.85 is 1998 x 1080 (1.85 : 1) and 2K 2.40 is 2048 x 858 (2.387 : 1).  But screen masking, curtains, spill over, etc. may all trim the image to some extent just as with film projection.


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#7 David Mullen ASC

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Posted 19 May 2015 - 11:51 PM

 

Is this intended to be perforation to perforation? I wasn't sure I'd seen that number before, so I checked Wikipedia - interestingly, Wiki lists different numbers for the perforation to perforation gate width of S35, VV, and Technirama. (Though the difference between VV and Technirama is possibly a rounding or conversion error.)

 

There has always been a slight difference between true 35mm Full Aperture, which is .980" wide (24.892 mm) and Super-35 extraction, which is .945" wide (24.003 mm) in some books.  Truth is that probably most cameras set-up for Super-35 are exposing Full Aperture, it's just that the ground glass lines are marked for the Super-35 area slightly within that.  And I'm not sure which width most scanners are using.


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#8 Mathew Collins

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Posted 08 June 2015 - 08:31 PM

David, just few questions:

 

Super-35mm which you speified is 3 perf or 4 perf?

 

Intially you said -> So that's a 2.11X difference with 5-perf 65mm (divide 52.48 by 24.89).  So if you use an 80mm lens on a 5-perf 65mm camera, you'd want to use a 38mm lens on a Super-35 camera to match horizontal view.

 

Later you said  -> It's a 1.76X difference between anamorphic and Super-35.  So to match a 38mm lens on a Super-35 camera, you'd use a 67mm anamorphic lens or that 80mm lens on the 5-perf 65mm camera.

 

Is it 2.11x difference or 1.76x difference?


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#9 Leon Liang

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Posted 08 June 2015 - 08:36 PM

It's a 2.11X difference between 5-perf 65mm and Super 35, and a 1.76X difference between anamorphic 35mm and Super 35. Therefore you would get the same (horizontal) angle of view with an 80mm on 5-perf 65mm, 67mm on anamorphic and 38mm on Super 35.
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#10 David Mullen ASC

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Posted 08 June 2015 - 11:40 PM

David, just few questions:

 

Super-35mm which you speified is 3 perf or 4 perf?

 

Intially you said -> So that's a 2.11X difference with 5-perf 65mm (divide 52.48 by 24.89).  So if you use an 80mm lens on a 5-perf 65mm camera, you'd want to use a 38mm lens on a Super-35 camera to match horizontal view.

 

Later you said  -> It's a 1.76X difference between anamorphic and Super-35.  So to match a 38mm lens on a Super-35 camera, you'd use a 67mm anamorphic lens or that 80mm lens on the 5-perf 65mm camera.

 

Is it 2.11x difference or 1.76x difference?

 

Didn't I explain that already?  It's a 2.11X difference between 5-perf 65mm and Super-35 -- doesn't matter whether it is 4-perf or 3-perf since we are talking about horizontal view, not vertical.  It's a 1.76X difference between 35mm anamorphic and Super-35.


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#11 Simon Wyss

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Posted 09 June 2015 - 01:36 AM

Standard 35mm sound projection gates are all .825" wide, which comes out to 20.955 mm.

 

70mm projection is 1.912" wide, which comes out to 48.5648 mm.

 

 

Which standards?

 

When I look up ISO 2907, Maximum projectable image area on 35 mm motion picture prints, I read 0.831" or 21,11 mm for the width plus the NOTE: It is intended that the actual projected image area be the largest appropriately shaped figure that can be inscribed within the specified dimension.

 

ISO 2467, Maximum projectable image area on 70 mm motion-picture prints: 1.913" or 48,59 mm plus the same NOTE as with ISO 2907.

 

 

This has to do with the fact that not in all cinemas projection is perpendicular to the screen. Gates will be hand-filed to restitute straight aperture edges on the screen. The aspect ratio of 1:1,37(5), by the way, is purely academic and found with the camera aperture dimensions that underwent several minor alterations. Standard silent and standard sound film projection aspect ratio is 1:1,333 or 4:3 since february 1909.


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#12 Mathew Collins

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Posted 09 June 2015 - 01:50 AM

It's a 2.11X difference between 5-perf 65mm and Super 35, and a 1.76X difference between anamorphic 35mm and Super 35. Therefore you would get the same (horizontal) angle of view with an 80mm on 5-perf 65mm, 67mm on anamorphic and 38mm on Super 35.

 

Thank you Leon.

 

If 1.76X difference between anamorphic 35mm and Super 35,

 

then could you explain what is 2x anamorphic squeeze?

 

Is that what we obtain on Super35 format using anamorphic lenses?


Edited by Mathew Collins, 09 June 2015 - 01:52 AM.

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#13 Leon Liang

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Posted 09 June 2015 - 02:28 AM

Anamorphic and Super 35 are basically two ways of obtaining a 2.35:1 aspect ratio.

In Super 35, you capture on 4- or 3-perf 35mm negative without a soundtrack and crop a 2.35:1 frame out of it.

In anamorphic, the image is captured on 4-percent 35mm with the soundtrack, so the negative has a 1.2:1 ratio, but anamorphic lenses squeeze 2x the horizontal field of view onto the frame, giving a very distorted image on the 1.2:1 negative; the image is then un-squeezed 2x by a reverse anamorphic lens during projection, projecting a 2.35:1 (well, technically 2.39:1 or 2.40:1) image.

So basically the reason why there's a 1.76 (or something of the sort) difference is that the Super 35 frame goes from perforation to perforation but the anamorphic frame has a soundtrack next to the image.

Check out the Wikipedia article about Super 35, or anything else on the web. It certainly explains it better than I do.
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#14 Mathew Collins

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Posted 09 June 2015 - 03:53 AM

Anamorphic and Super 35 are basically two ways of obtaining a 2.35:1 aspect ratio.

In Super 35, you capture on 4- or 3-perf 35mm negative without a soundtrack and crop a 2.35:1 frame out of it.

In anamorphic, the image is captured on 4-percent 35mm with the soundtrack, so the negative has a 1.2:1 ratio, but anamorphic lenses squeeze 2x the horizontal field of view onto the frame, giving a very distorted image on the 1.2:1 negative; the image is then un-squeezed 2x by a reverse anamorphic lens during projection, projecting a 2.35:1 (well, technically 2.39:1 or 2.40:1) image.

So basically the reason why there's a 1.76 (or something of the sort) difference is that the Super 35 frame goes from perforation to perforation but the anamorphic frame has a soundtrack next to the image.

Check out the Wikipedia article about Super 35, or anything else on the web. It certainly explains it better than I do.

 

Can i put it in this way...

 

we use anamorphic lens on 4-perf 35mm with the soundtrack and never use never anamorphic lens on 4 or 3 perf Super 35 format?


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#15 Leon Liang

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Posted 09 June 2015 - 04:00 AM

Can i put it in this way...
 
we use anamorphic lens on 4-perf 35mm with the soundtrack and never use never anamorphic lens on 4 or 3 perf Super 35 format?


Well, we can do that, we just don't...I mean, we use digital sound now so we don't need that soundtrack space, and there's no big concern about Super 35 grain because we mostly use DI and not optical conversion (I'm not sure how the optical stuff works, but David does!).

I think Rodrigo Prieto used anamorphics on 4-perf Super 35 for 'The Wolf of Wall Street' because he used anamorphic for some parts of the film and Super 35 for others, so there was no point ordering some stock with the soundtrack space and some stock without. For the anamorphic scenes he just cropped the 2.39:1 frame from the 2.66:1 negative.
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#16 Mark Dunn

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Posted 09 June 2015 - 04:11 AM

ordering some stock with the soundtrack space and some stock without

The stock is the same. The difference is in the lens centring.


Edited by Mark Dunn, 09 June 2015 - 04:12 AM.

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#17 Leon Liang

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Posted 09 June 2015 - 04:16 AM

The stock is the same. The difference is in the lens centring.


Yeah, I actually just found that out while reading the other forum regarding lens centering that Matthew Collins was just on.
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#18 Mathew Collins

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Posted 10 June 2015 - 01:51 AM

 

Didn't I explain that already?  It's a 2.11X difference between 5-perf 65mm and Super-35 -- doesn't matter whether it is 4-perf or 3-perf since we are talking about horizontal view, not vertical.  It's a 1.76X difference between 35mm anamorphic and Super-35.

 

Thank you David.


Edited by Mathew Collins, 10 June 2015 - 01:51 AM.

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#19 Mathew Collins

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Posted 10 June 2015 - 01:52 AM

Well, we can do that, we just don't...I mean, we use digital sound now so we don't need that soundtrack space, and there's no big concern about Super 35 grain because we mostly use DI and not optical conversion (I'm not sure how the optical stuff works, but David does!).

I think Rodrigo Prieto used anamorphics on 4-perf Super 35 for 'The Wolf of Wall Street' because he used anamorphic for some parts of the film and Super 35 for others, so there was no point ordering some stock with the soundtrack space and some stock without. For the anamorphic scenes he just cropped the 2.39:1 frame from the 2.66:1 negative.

 

 

Thank you Leon.


Edited by Mathew Collins, 10 June 2015 - 01:53 AM.

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