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Abdul Rahman Jamous

What would happen if my squeezed anamorphic lens occupied the whole recording area of a sensor?

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More or less correct, a 2X squeeze on a 16x9 HD recording (1.78 : 1) gets you a 3.56 : 1 image more or less once unsqueezed. Now whether you unsqueeze it by doubling 1920 pixels horizontally or halving 1080 pixels vertically is up to you but I assume you want to end up with a very narrow 3:56 : 1 letterboxed image in HD.

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Let's say that I'm the DP of a project and I would like to use anamorphic lenses. Are there any form of calculations that I have to do before shooting in order to make sure that my anamorphic image wouldn't be scaled down in post?? or do I have to test things out.

This is the EXACT reason why I created the topic: How to figure out the aspect ratio of a squeezed anamorphic lens?

 

 

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As I said before, you always work backwards from where you want to end up to figure out the best way to start.  What delivery format, what aspect ratio, etc. Until you have an answer to those questions, you can't really figure anything out.

There are always forms of cropping and scaling to create a final product, you just have to choose the optimal path.

Besides, scaling down (oversampling) is almost always preferable to scaling up.

But if you're talking about actual resolution, what matters is the area of the sensor you used to create the final image, desqueezing a 2X anamorphic image by doubling the horizontal number of pixels is not adding resolution.

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8 hours ago, Abdul Rahman Jamous said:

Let's say that I'm the DP of a project and I would like to use anamorphic lenses. Are there any form of calculations that I have to do before shooting in order to make sure that my anamorphic image wouldn't be scaled down in post?? or do I have to test things out.

This is the EXACT reason why I created the topic: How to figure out the aspect ratio of a squeezed anamorphic lens?

 

 

The lens doesn’t determine your final aspect ratio and finishing format. You decide that first, along with your director - this is the target. Then you pick the lens and camera format, and inform whomever is doing post of what your project’s aspect ratio is. If you are finishing in an aspect ratio that isn’t available in the camera as a native format, then you crop in post to get the desired ratio.

So if you decide that you want to finish in 2.39:1, you can either shoot with spherical lenses and crop vertically, or use anamorphic lenses and crop horizontally. If you want to avoid cropping, then you need to start with a spherical widescreen format (like 35mm 2-perf or Red’s Widescreen formats), or a 1.19:1 format (like 35mm 4-perf with an anamorphic gate or Alexa 6:5 format) and use 2x anamorphic lenses that will desqueeze to 2.39:1. There are other more obscure wide aspect ratios and anamorphic squeeze ratios out there, but these are by far the most common ones.

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10 hours ago, Abdul Rahman Jamous said:

one thing I forgot to mention, my recording resolution is also 1920HD.

Ok. So if you’re starting with a 1920x1080 camera, then your native aspect ratio is 1.78:1. If your final intended aspect ratio is 2.39:1, then you’re gonna have to crop a lot, either vertically with spherical lenses or horizontally with 2x anamorphic lenses.

I would recommend setting up a project in Davinci Resolve in 2.39:1 (1920x803) and dropping your footage into the timeline. The cropping will be done for you automatically, and you can then pan and scan the footage inside the 2.39:1 window to fit as needed.

Depending on what camera you are shooting on, there may be frame guides available that will help you frame up your shots, even if your shooting format and finishing format are quite different. It’s also a good idea to shoot a framing chart in prep to communicate to post your intended final framing.

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So I read thru your other topic, and I’m a bit confused on what you are trying to achieve. You said you were not concerned about the final aspect ratio? 

Are you just trying to achieve the widest image possible without cropping or having black bars on the final image? Like a photo panorama? 

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The thing is: rescaling is inevitable — the image is anamorphic and most digital delivery formats use an unsqueezed image so it has to be rescaled on the horizontal or vertical axis to get rid of the squeeze. And some cropping is inevitable as well if you need to deliver in some standardized aspect ratio. Plus there are only so many types of delivery formats that you have to work within.

Even with film, the aspect ratio of the final result is a combination of the squeeze factor and the area of the film used to create the image and generally you don't use the entire negative because if you shoot 4-perf 35mm, the entire negative is 1.33 : 1, so the unsqueezed image is 2.66 : 1.  So it's the squeeze ratio + the cropping amount that determines the aspect ratio.  Unless you want to keep the entire negative area or sensor area and live with whatever aspect ratio results, assuming the lens fills that area with image. But most sensors today are widescreen already, 1.78 or 1.9 : 1, etc. so a 2X squeeze creates an extremely widescreen image if you don't crop, hence the recent interest in less-than-2X like 1.3X, 1.66X, 1.8X.

 

 

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2 hours ago, David Mullen ASC said:

The thing is: rescaling is inevitable — the image is anamorphic and most digital delivery formats use an unsqueezed image so it has to be rescaled on the horizontal or vertical axis to get rid of the squeeze. And some cropping is inevitable as well if you need to deliver in some standardized aspect ratio. Plus there are only so many types of delivery formats that you have to work within.

Yes, indeed. I’m curious about the context of Abdul’s question because it occurred to me that he may not be trying to make a film that conforms to existing display standards.

In the past, filmmakers have mostly been restrained by strict delivery standards whether for film projection and DCI specs in the cinema, or broadcast, network, and studio specs. Only people shooting for art installations and other small niche industries could get away with doing their own thing. But with online self-publishing, things are a bit looser now. 

For example, I shoot this annual Shakespeare project for the educational market where the aspect ratio can be whatever we want. The video clips get hosted on Vimeo and are intended to be viewed directly on the client’s website in a browser pop-up window.

For that reason, and because I have to sometimes fit up to 8 actors into a shot and preferably frame them no wider than waist-up so as to capture all the nuances of their facial expressions, I shoot in a non-standard 2.64:1 aspect ratio (DCI 4K with a 1.4x anamorphic squeeze lens), which is the widest format I can achieve with the equipment I own. The anamorphic lens allows me to use a 35mm focal length and maximize the horizontal use of our stage set, while not foreshortening the Z-axis too much and allowing me to place lights just above and below the frame line. It works pretty well in our use case - since we are not shooting any coverage, it’s pretty much like shooting a stage play in a locked proscenium shot, but with a fairly tight frame and controlled blocking. 

Anyway, I just wondered if Abdul was doing something like that. 

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Maybe 20 years ago I walked into the Navy Museum in Washington D.C. because it had a sign outside that said "70MM!" (for me, that's like a sign that says "GIRLS, GIRLS, GIRLS" for some other gentlemen...) So I watched this IMAX-like doc on aircraft carrier life that was projected in an aspect ratio between 3:1 and 4:1 on a curved screen for a pseudo-Cinerama effect.

Afterwards I went to the projectionist and asked him what I had seen, which was standard 5-perf 70mm 2.20 : 1 framed for cropping. The film had been made specifically for the museum.

As a side note, a friend of mine used to joke that Ernest Borgnine was actually in every movie, just off-camera in some of them... the screening in the museum was attended by some WW2 vets and their spouses and after the screening, there was an announcement that the guest for the day was WW2 vet Ernest Borgnine, who stepped out from behind the curtain. So I guess he really was in every movie, just sometimes behind the theater curtain!

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42 minutes ago, David Mullen ASC said:

Maybe 20 years ago I walked into the Navy Museum in Washington D.C. because it had a sign outside that said "70MM!" (for me, that's like a sign that says "GIRLS, GIRLS, GIRLS" for some other gentlemen...) So I watched this IMAX-like doc on aircraft carrier life that was projected in an aspect ratio between 3:1 and 4:1 on a curved screen for a pseudo-Cinerama effect.

I recall IMAX screens being a surprisingly regular thing at various DC Smithsonian Museums. Did you view any of the other IMAX screens on the mall?

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14 minutes ago, Max Field said:

I recall IMAX screens being a surprisingly regular thing at various DC Smithsonian Museums. Did you view any of the other IMAX screens on the mall?

Yes, I often saw IMAX movies at the Air & Space Museum -- I moved to northern Virginia in 1978 when I was 16 and spent my first summer watching "To Fly" there many times. The bookstore in the museum is where I found a copy of "The Making of '2001'" -- changed the course of my life possibly.

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My question is math.

If I know the dimensions of my squeezed image and the aspect ratio of my de-squeezed image, how I may know the  dimensions of my de-squeezed image.

guess what... more illustrations!

 

This question has been in my mind for a over a year and finally I'm confident enough to ask it.

What I'm looking for are values, numbers. So please please I beg you don't mention cropping for me because this is not my question🤣

A.PNG

B.PNG

C.PNG

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is this a trick question? isn't just simple math?

1280/720=1.77

desqueezed image height is still 720, but the aspect ratio is 3.56, so desqueezed image size is
720x3.56=2563.2
2563x720
 

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You can choose any pixel dimensions you want or need as long as you double the horizontal value relative to the amount you change the vertical value to get rid of the 2X squeeze.

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Since UHD is exactly double the width and double the height of HD, you could shoot 1920 x 1080 HD with a 2X lens and then double 1920 to 3840 but leave the height at 1080, and end up with a letterboxed UHD image.

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Posted (edited)
3 hours ago, David Mullen ASC said:

As a side note, a friend of mine used to joke that Ernest Borgnine was actually in every movie, just off-camera in some of them... the screening in the museum was attended by some WW2 vets and their spouses and after the screening, there was an announcement that the guest for the day was WW2 vet Ernest Borgnine, who stepped out from behind the curtain. So I guess he really was in every movie, just sometimes behind the theater curtain!

Hah! I bet you peeked behind every stage curtain for a few years, just to make sure. 

I still see some 4:1 aspect ratios being used for trade show projection. One of my first AC jobs was on one of these shoots. We used a Panasonic HPX500, which was a 720p camera. So once cropped, the vertical res would have been 320p. A far cry from 70mm!

Edited by Satsuki Murashige

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