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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

4:3 Epic

I agree that a 4x3 or to be more specific, a super 35mm full frame sensor would be ideal. Then the windowing can go through 16:9, 2.4:1, etc, all keeping the width. Plus, if folks want to shoot anamorphic they can,using the whole sensor. And Imax with the whole sensor.
 
Craig Ryan said:
with 2.40:1 anamorphic, if it IS a 5k 4:3 sensor, that would yield a projected 9216 x 3840 image...9.2k if you like...:love:
Click to expand...

Craig Ryan said:
Here's a Microsoft paint quicky scaled down to 10% just to get an idea of the real difference in size between the possibilities:


49_1214984255.jpg


So as we can see even if EPIC is a 16:9 sensor, there will still be a significant difference between it and the new 4.5k RED ONE spec.
Click to expand...

How come 5K 4:3 (with 2.40:1) become 9216x3840???
AFAIK, full aperture of 5K is 5120x3890.
 
Its just theoretical resolution; if you had a 4:3 sensor, shot with anamorphic 2.40:1 glass, the projected resolution would be stretched horizontally.
 
Now I'm not so certain...I wouldn't doubt it if I'm missing a critical aspect (no pun intended) here...in my limited knowledge, when anamorphic glass is used to yield a 2.40:1 image, the film stock used is a 4:3 film format right? With this logic, I calculated:

EPIC theoretical 5k 4:3 sensor = 5120 x 3840

INTENDED ASPECT RATIO: 2.40:1

3840 X 2.40 = 9216.

EDIT: This doesn't necessarily mean the image will RESOLVE that much resolution, but that should be size of the image.

If this is incorrect, by all means, help me out here. Willing to learn the ways of the force.
 
how are the number of horizontal lines staying the same??
 
Anamorphic lenses normally have a 2X squeeze, so the projection gate is roughly 1.20 : 1, unsqueezed optically to 2.40 : 1.

The pixel resolution of an anamorphic image is whatever it is - optically doubling the width during projection doesn't double the pixel resolution, all it does is reduce loss of vertical resolution compared to cropping to achieve 2.40 -- in other words, the main resolution advantage to shooting with anamorphic lenses versus cropping a spherical image to 2.40 is increased vertical resolution due to not cropping, not increased horizontal resolution.

I don't have the exact numbers, but a 4K file for an anamorphic image is around 4096 x 3428, whereas a 4K file cropped to 2.39-ish for a film-out is around 4096 x 1714. So you have twice the vertical pixel resolution for the 35mm release print. It's less important if you are talking about digital projection though since they don't use anamorphic lenses for DCI projectors, they just crop vertically. So the anamorphic image would be converted to a spherical one and end up with the same pixel dimensions for projection digitally, though I guess there may be some improvement from downrezzing an anamorphic image vertically.

If you put a 2X anamorphic lens on a 4x3 (1.33 : 1) sensor, the unsqueezed image would be 2.66 : 1. So what gets used is slightly more square than 4x3.

The original intent of CinemaScope was to use Full Aperture (silent) 1.33 : 1 with the 2X anamorphic squeeze to get a 2.66 : 1 image that would compete with Cinerama (whose three 6-perf 35mm spherical images added up to a 2.66 : 1 frame).

And the sound would have run interlock on a separate 35mm mag track, as it was for Cinerama projection. But quickly they decided to put the soundtrack on the CinemaScope print, which shaved the width down from 2.66 : 1. With smaller CS perfs in the print and mag stripes on both sides of the projected frame, the image was shaved down to 2.55 : 1.

Then they decided to go with a standard optical soundtrack on the left side, which offset the image (as with standard Academy and 1.85) and trimmed the size further to 2.35 : 1. This is why modern contact prints of early CinemaScope movies like "20 Thousand Leagues Under the Sea" look offset, the titles not centered -- because the image was centered on the negative and meant to be projected in 2.55 : 1.

Then in the early 1970's, the anamorphic gate was shaved down top & bottom slightly, made a little less tall, to hide negative splices better, changing the aspect ratio to nearly 2.40 : 1 (2.39... : 1) once unsqueezed by the 2X anamorphic projector lens.

What this means is that IF the EPIC sensor is 5120 x 3840... then a "scope" image (2.39... : 1 with a 2X squeeze) would end up trimming the sensor image from 1.33 : 1 to 1.19.. : 1, or to around 4570 x 3840 if you used the max vertical pixel resolution.

And then for a 4K film-out to 35mm anamorphic, this would be downrezzed to 4096 x 3442-ish... and for 4K DCI projection, it would be downrezzed vertically and unsqueezed to 4096 x 1714-ish (assuming 4096 is the correct figure for 4K projection standards.)

At no point would the horizontal file size be doubled to the 9K range... you have to keep in mind that either you retain the square-ish file dimensions and keep the 2X optical image squeeze, which is fine for a film-out to 35mm anamorphic... or you unsqueeze the image to a standard file size for digital projection, and there's no reason to change the dimensions horizontally to the 9K range as opposed to stick to the 4K range and reduce the vertical. Not until we have 9K projectors...
 
Hi Tom,

Bare with me here, I'm not trying to patronize you or anything, just kinda thinking out loud to explain myself. :)

The theoretical sensor is 5k 4:3 with 5120 x 3840 res but when you shoot with the anamorphic glass, you're squeezing a 2.40:1 image into that 4:3 frame, so when its projected at the right aspect ration, you retain the vertical 3840 res, so in theory *holds up index finger*, you would get a projected, 9216 2.40:1 image. Am I way off or something? :)

EDIT: didn't see David's post above before posting this. Thanks David!

So what I learned; while the image will retain vertical res, the horizontal resolution won't change..and with current projection technology, the image is going to be converted to a cropped 4k file for digital spherical projection, which means oversampling which is always great.
 
You got to keep straight the difference between film projection and digital projection. 35mm anamorphic print projection doesn't have pixels... and when you shoot with standard 2X anamorphic lenses, you have a file that is roughly 1.19... : 1 with a 2X image squeeze. That is what gets recorded to 35mm.

If you shot with spherical lenses and cropped to 2.39... : 1, then your file size would be cropped vertically to 2.39... : 1 and the laser recorder would basically scan out every line twice to double the height of the image and create a 1.19... : 1 frame with a 2X image squeeze. The 2X anamorphic projector lens corrects this to 2.39... : 1.

Most digital projection nowadays uses spherical lenses so you have to convert your 2X anamorphic image to a spherical image in the dimensions that the digital projector uses. So while one could just double the horizontal pixel dimensions rather the cut in half the vertical pixel dimensions... there are no 9K projectors out there.
 
Which is why I have said in the beginning I don't see reason for EPIC to be 4:3. It only makes sense for anamorphic film out. Now - realistically - how many people will buy Epic to shoot 4:3 with anamorphic lenses for analog film out for anamorphic projection??? This would make one "elitist" camera - no offense...

4:3 would make sense for still photography, but then again - who is going to buy $40K Epic to shoot stills?

I think the way forward is 16:9 - which seems to be the standard nowadays for all new digital cine & video cameras. This way new 1.33x anamorphic lenses could be developed for both filming and projection if there is substantial demand...

Just my two pesos...
 
shooting anamorphic in digital makes less quality than cropping from the native capture.(this one is for the less smart people - i'm talking about the digital capturing and manipulation of the files not to do anything with any imperfections with the anamorphic lens)

there are allot of advantages from a 4:3 camera as oppose to a 16:9.

for example, a 4:3 camera that have an option of 2.4 aspect, would run much smoother than a 16:9 camera.(and that can start a whole new chain reaction that can also lead to faster fps, better audio recording, added features in the viewers, better sync with other cameras or ext audio.)

shooting 4:3 and having about or 2x the height can lead to all kinds of new possibilities.

it would have more look around room.

there are tons more of advantages, but i'm not going too deep into it for the sake of my peace.
 
Peter Majtan said:
Which is why I have said in the beginning I don't see reason for EPIC to be 4:3. It only makes sense for anamorphic film out. Now - realistically - how many people will buy Epic to shoot 4:3 with anamorphic lenses for analog film out for anamorphic projection??? This would make one "elitist" camera - no offense...

4:3 would make sense for still photography, but then again - who is going to buy $40K Epic to shoot stills?

I think the way forward is 16:9 - which seems to be the standard nowadays for all new digital cine & video cameras. This way new 1.33x anamorphic lenses could be developed for both filming and projection if there is substantial demand...

Just my two pesos...
Click to expand...
Do you meant there are no advantages to use 4:3 sensor other than for anamorphic film out???
 
There's no reason why a 4:3 digital camera would run "smoother" than a 16:9 camera. In fact, look at the problems of getting 4K 16:9 to work compared to 4K 2:1 in the RED -- more vertical information is more data to process and compress, etc. More data means reduced frame rate options, more chance for codec errors, etc.

Certainly if you are going to crop to 2.40, there is no advantage of 4:3 over 16:9 other than you are wasting a lot more of the sensor with 4:3 being cropped. It's the same reason why 3-perf 35mm (16:9) is becoming more popular than 4-perf 35mm (4:3) even for 2.40 projects.

The advantages of 4:3 sensor are:
* For 4:3 projects (which lie in the extremes -- standard def TV and IMAX...)
* For vertical repositioning, especially useful for visual efx plates and material to be rear-projected for process shots
* 2X anamorphic lens photography for 2.40 projects

Greater lookaround in the viewfinder doesn't necessarily mean you need a 4:3 sensor, you could just have an oversized 16:9 sensor for extra space on all sides, not just top & bottom.

Also, the higher the resolution of the sensor, the less it matters one way or the other since there is not much loss from cropping.
 
To me, the #1 reason for 4:3 is IMAX.

The specs being discussed for Epic don't seem that far off from 5-perf 65mm if the film is put through a scanner.

BTW, David, is there much or any degraining done to 5-perf 65mm in the DMR to 15-perf? Or it is just a straight optical blow up?
 
I don't know of any 5-perf 65mm project that did a straight optical printer blow-up to IMAX. There have been clips, I remember some older IMAX movies about visual effects that had a letterboxed image from "2001" that was probably an optical blow-up.

But nowadays, any conversion to 15-perf IMAX will probably be done digitally. As to whether it needs some sharpening + degraining... well, it would depend on the quality of the 5-perf 65mm photography. I'm sure Dave Keighley at the DMR facility would do some tests to determine the amount of sharpening + degraining needed to not be distracting on a big IMAX screen, maybe very little would be needed for 5-perf 65mm photography. It may depend on if it were shot on 50 ASA film or 500 ASA film.
 
David Mullen ASC said:
There's no reason why a 4:3 digital camera would run "smoother" than a 16:9 camera. In fact, look at the problems of getting 4K 16:9 to work compared to 4K 2:1 in the RED -- more vertical information is more data to process and compress, etc. More data means reduced frame rate options, more chance for codec errors, etc.

Certainly if you are going to crop to 2.40, there is no advantage of 4:3 over 16:9 other than you are wasting a lot more of the sensor with 4:3 being cropped. It's the same reason why 3-perf 35mm (16:9) is becoming more popular than 4-perf 35mm (4:3) even for 2.40 projects.

The advantages of 4:3 sensor are:
* For 4:3 projects (which lie in the extremes -- standard def TV and IMAX...)
* For vertical repositioning, especially useful for visual efx plates and material to be rear-projected for process shots
* 2X anamorphic lens photography for 2.40 projects

Greater lookaround in the viewfinder doesn't necessarily mean you need a 4:3 sensor, you could just have an oversized 16:9 sensor for extra space on all sides, not just top & bottom.

Also, the higher the resolution of the sensor, the less it matters one way or the other since there is not much loss from cropping.
Click to expand...
If we take a 4:3 active frame from a 16:9 sensor of 5K, we get an active frame smaller than 5120x3890 (full aperture from 4:3 sensor of 5K) right?
 
David Mullen ASC said:
I don't know of any 5-perf 65mm project that did a straight optical printer blow-up to IMAX. There have been clips, I remember some older IMAX movies about visual effects that had a letterboxed image from "2001" that was probably an optical blow-up.

But nowadays, any conversion to 15-perf IMAX will probably be done digitally. As to whether it needs some sharpening + degraining... well, it would depend on the quality of the 5-perf 65mm photography. I'm sure Dave Keighley at the DMR facility would do some tests to determine the amount of sharpening + degraining needed to not be distracting on a big IMAX screen, maybe very little would be needed for 5-perf 65mm photography. It may depend on if it were shot on 50 ASA film or 500 ASA film.
Click to expand...

Didn't Baraka get an IMAX run? I was living outside the US when Baraka was released so I am unsure about that.

If you happen to talk to Dave Keighley, would you mind asking him if he thinks a 21MP Canon 1DsM3 frame would blow up nicely to 15-perf IMAX, and same thing with EPIC? I'm curious to know if these technologies are on their radar screen.

I guess they could always take a 5- or 6K movie and downsample it to 4K, then show it on their new "4K IMAX" system. :(
 
Tom said:
Didn't Baraka get an IMAX run?
Click to expand...

"Baraka" was released in standard 5-perf 70mm; the prints still play now & then at 70mm festivals. If it were shown in an IMAX theater, odds are that they would have dragged in a 5-perf 70mm projector into the theater to show it. I don't recall a blow-up to IMAX for that movie. Ron Fricke did make "Chronos" (1985) in IMAX, I remember seeing that.
 
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