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If you want a very in depth technical look at the differences between IMAX 70mm, 70mm and 35mm for _The Odyssey_, I wrote an article about this last month. htt

If you want a very in depth technical look at the differences between IMAX 70mm, 70mm and 35mm for _The Odyssey_, I wrote an article about this last month. https://www.theppt.org/rewind/articles/where-can-you-watch-the-odyssey-on-35mm-70mm-imax-70mm-film-and-what-format-should-you-pick/ https://www.theppt.org/rewind/articles/where-can-you-watch-t... But here are my nit-picks from the article linked here. I'm only commenting on the 15/70mm IMAX parts, because I'm not knowledgable enough about the digital IMAX foramats. > The extra resolution, up to 18K equivalent The claim of 18K is entirely untested. No one has ever measured what the theoretical resolution of an 15/70mm IMAX system is. Kodak's film may me theoretically capable of resolving this, but what about the camera lens, the GT projector lens and field flattener, and everything else involved? Until a study is actually done, I don't think the 18K is a good number to band about. > thanks to the use of single or even dual 15kW water-cooled xenon bulbs No cinema is using dual lamps. The dual lamps are used for 3D - one lamp per "eye" (right and left). But no 15/70mm IMAX is currently showing 3D, I think the last was the London Science Museum (but that's a guess, so don't take as truth). So it is only single lamp. 15kW is also not always true - some smaller 15/70mm IMAXes use 12kW or around that. > However, there are only around 24 such theaters in the US, nine in Canada and six elsewhere around the world. This is incorrect. There are actually 25 in the US, and 7 in the rest of the world, totalling 41 prints.

derbOac 2mo ago
Not a complaint about your post but this stuff about film formats and aspect ratios has always had me scratching my head. For years I heard people arguing that wider aspect ratios were preferable because they afforded a wider view, and that narrower aspect ratios were too restrictive horizontally. This always seemed confusing to me because theoretically they should allow for more vertical space for the same width. Now we're being told the opposite. Obviously if the full frame is being cut for different formats, you're losing some of the shot, so maybe this all reduces to what the director wants, and what is being lost relative to that in different formats. But then this brings me to my second source of confusion: > If you watch it in IMAX 70mm, you are seeing it in the full 1.43:1 aspect ratio, which will probably be the only way to experience this format. It would be unprecedented for this full picture to be released on Blu-ray or on streaming, so watching it in a cinema on IMAX 70mm is your chance to experience this. Why can't releases just be scaled to fit on a screen? You could take that IMAX70mm and scale it down to fit on a different aspect ratios. You'd end up with black bars on the sides of the screen, but then you'd see the same shot, just shrunk down. Everyone has a different TV size anyway so it's all relative. Clearly resolution plays a role, but IMAX70mm isn't going to be low resolution, and none of this will matter for home viewing anyway. All of these discussions ultimately seem odd to me. I understand the projection format constraints in movie theaters, but at some point it seems possible to just downscale everything to every aspect ratio format. They've done it here, so in theory they could just release all these versions as part of a physical disc set (or stream them all): https://www.odysseymovie.com/explore-formats/ https://www.odysseymovie.com/explore-formats/
- ubercore 2mo ago
  Originally a lot of HDTV would present SDTV with black bars on the sides. People don't like it.
- xdertz 2mo ago
  You can also watch 1.43:1 in a virtual cinema in VR.
  - MetaWhirledPeas 2mo ago
    Only if the media is published in that format.
  - SirMaster 2mo ago
    Pretty much no movies are released in that aspect except like justice league Snyder cut.
- mchristen 2mo ago
  It can definitely be confusing. For example, traditionally still film cameras used 35mm film, but cinema cameras also used 35mm film. However the cinema cameras capture the image vertically instead of horizontally on the film, otherwise known as a Super 35. Literally the film runs through the camera vertically instead of horizontally. In order to make an image work that is understandable to our brains you either need to do heavy cropping and waste tons of film, or you use an anamorphic lens to "squeeze" more light onto the film. You then have to reverse that when you go to project the film.
- ralferoo 2mo ago
  > Now we're being told the opposite. The choice of unusual film standards has always been to make the film a bit "special" when viewed in a suitable cinema. The original format 1.33:1 was simply using 35mm wide film (originally 1.35") and after putting sprocket holes on each side, there was 1" of usable width, and someone decided to make a frame 1" x 0.75". The projected image was just scaled linearly. When they started adding audio, the image was shrunk slightly to 22mm x 16mm (the ratio of this image was modified slightly to 1.375:1), and the audio track was just placed between the right hand edge and sprockets. They could use the same projector technology, just with a mask between the film and the lens so that the audio track didn't appear on the screen, and an optical pickup head for the audio that was placed below the mask and lens. As an aside - a silent movie projector has a complicated gear system that advances the film 4 sprockets in a jerk, once every 24 times per second, while before and after that it is fed smoothly (so you have a "loop" of film above and below to take up the slack). You also have a shutter that closes for half the frame to hide the film when it's actually moving, and open when it's stationary. When the audio passes the audio sensor after the bottom loop, it's moving linearly, so the amount of light that can pass through a narrow slit is proportional to the voltage sent to the speaker. Later when stereo was added to films, they just fit 2 audio tracks into the space of one, so mono films would work on stereo projectors and vice versa. And even later, Dolby surround was encoded as a dot matrix pattern in between the sprockets (actually, it was just a film ID and timecode that was encoded) and the audio itself came from the 3-5 CDs that came with each film. But I'm getting ahead of myself. These two standards stuck around for quite a while and then some of the later experimental TV systems started also using this ratio, probably to making filming non-live TV possible / easier as they could use the film process and show it on a TV using a telecine without wasting any of the image space. Once TVs started to become popular, directors started wanting to make their films more special, something that couldn't be experienced the same way on a TV. And so began the arms race on picture formats. For a while 1.66:1 was popular, which used the same projectors as before but changed out the lens for an anamorphic lens which squished the image to make it wider. And soon, 1.85:1 was standardised (with a different anamorphic lens and mask). This was known as "flat" and was used by the majority of films. Some of the higher budget films were produced in 2.35:1, known as cinemascope or just "scope" and so now most cinemas had 3 sets of masks and lenses - square, flat and scope - and could show pretty much everything with a pair of projectors just by swapping the lenses. A few special aspect ratios were tried, but these were usually limited distribution to specialised cinemas, and cropped to a standard size for regular cinemas. In this era, usually the curtains could move to the correct width for each film, or fully closed. 70mm film has been around for quite a long time, but never really caught on as it was expensive to shoot - non standard cameras, roughly 4 times the area of film (and so at least 4 times the cost, but more because demand was lower), and limited where it could be seen as most projectors were 35mm only. It was possible to get projectors that had a swappable gate so you could also show 70mm film, but they were relatively rare - probably less than 10% of cinemas had these. The aspect ratio was almost always 2.2:1, and so while it was narrower than scope format, people would pay extra for the 70mm experience because of the higher quality (and less grainy look). In the 1990s, TVs started shifting to 16:9 (1.77:1) which was a half-way compromise between improving the quality for films (1.85:1 scope doesn't need to be cropped much or only has small bars top and bottom) and leaving masses of unused space for older 4:3 TV broadcasts. However 16:9 was never used for cinema, and more directors switched to 2.35:1 for films after that to keep the "better in cinema" quality. So personally, I don't think 1.43:1 is really any better for 70mm (after all the film is so much bigger, the quality is already improved), rather it's almost certainly been chosen so that it looks different, and much better at cinema. Just as films shown in "letterbox format" on TV with half the screen black looked bad on a 4:3 TV, now pretty much every TV is 16:9, watching a 1.43:1 film on it will have big black bars on the side and detract from the experience. The cinema will be the best place to watch this. So, IMHO, it's all just a marketing gimmick aimed at those that want to pay a premium to see a film as the director intended it.
JimsonYang 2mo ago
7 or 8 of which are in California
qingcharles 2mo ago
18K seems high. I did some tests for Universal once and we pulled 10K from some 70mm IMAX ride prints. 8K was solid, 10K was very borderline.
- KaiserPro 2mo ago
  I'm trying to remember what resolution we rendered two face for when it went into imax. This was using 32bit renderman, and it was constantly OOM'ing because we were really pushing it. I seem to recall that we rendered out at 7k, even though the optical resolution was meant to be 12k.
  - BuildTheRobots 2mo ago
    I wonder if the render resolution was actually determined by the output resolution of the film recorder being used to get the sfx out onto film for display? I can't obviously find a film recorder that offers more than 8k on 65mm/15-perf. As I've not seen anyone else mention it, I feel the need to point out that Digital IMAX (which is the vast majority of screens and showings) maxes out at 4K.
    - KaiserPro 2mo ago
      https://www.awn.com/news/framestore-puts-grave-face-harvey-dent https://www.awn.com/news/framestore-puts-grave-face-harvey-d... Tim webber says it was rendered at 4k. Which contradicts what I remember. If he meant 4k textures that would make sense. 4k textures might have been why renderman kept on OOMing though and we had to tile the render even more. Also I don't know how they printed it back out to film. It might have been sent to hollywood to laser/print out.
dagmx 2mo ago
Thank you very much for the corrections here. As someone else who has professionally worked in the film space, it always irks me when people talk about film in digital resolutions for the reason you mention. I also agree with many of your other corrections but that is the one I wanted to ageee with the most as it’s my biggest pet peeve when I see people claim “film” is equivalent to a given resolution. Anything analogue can be (almost) infinitely resolved but that doesn’t mean it’s going to be effectively good at all those resolutions. Almost nobody thinks of the quality of medium and lenses when making those claims.
SirMaster 2mo ago
I am not even sure why the theoretical resolution matters when they seem to have so much trouble pulling focus on the actors on an old film camera like the IMAX cameras they use to where the footage is fairly blurry in a lot of cases. If they used a 6.5K or 8K digital cinema camera they would get all the advanced autofocus abilities those camera have nowadays to keep the actors sharply focused and would end up with more detail in the end.
- kridsdale1 2mo ago
  Sensor size. Depth of field is optically different on large frame cell size or sensor size vs 35mm. That camera you reference is not optically equivalent.
  - SirMaster 2mo ago
    Sure, but if you watch the Odyssey, you would see how the camera operators struggled to keep focus in some scenes. A modern digital cinema camera would have no trouble with it's advanced auto focus abilities. So the resolution of the film is kinda irrelevant because of that some of the time.
qingcharles 2mo ago
To add another nit-pick to the list, the author confuses 18K as being four times the resolution of 4K. 8K is four times the resolution of 4K. (counter-intuitively to most people as it only measures the pixels in one dimension yet the image resolution is increased in both width and height) Diagram: https://i.pcmag.com/imagery/articles/07toBDd6lpyucCyM0xWrcQv-1..v1569470731.jpg https://i.pcmag.com/imagery/articles/07toBDd6lpyucCyM0xWrcQv...
prmoustache 2mo ago
There is no such thing as resolution in films. There is accutance and sharpness, but it is not resolution.
- anfractuosity 2mo ago
  Wouldn't line pairs / mm count as resolution.
486sx33 2mo ago
[dead]

derbOac 2mo ago

Not a complaint about your post but this stuff about film formats and aspect ratios has always had me scratching my head. For years I heard people arguing that wider aspect ratios were preferable because they afforded a wider view, and that narrower aspect ratios were too restrictive horizontally. This always seemed confusing to me because theoretically they should allow for more vertical space for the same width. Now we're being told the opposite. Obviously if the full frame is being cut for different formats, you're losing some of the shot, so maybe this all reduces to what the director wants, and what is being lost relative to that in different formats. But then this brings me to my second source of confusion: > If you watch it in IMAX 70mm, you are seeing it in the full 1.43:1 aspect ratio, which will probably be the only way to experience this format. It would be unprecedented for this full picture to be released on Blu-ray or on streaming, so watching it in a cinema on IMAX 70mm is your chance to experience this. Why can't releases just be scaled to fit on a screen? You could take that IMAX70mm and scale it down to fit on a different aspect ratios. You'd end up with black bars on the sides of the screen, but then you'd see the same shot, just shrunk down. Everyone has a different TV size anyway so it's all relative. Clearly resolution plays a role, but IMAX70mm isn't going to be low resolution, and none of this will matter for home viewing anyway. All of these discussions ultimately seem odd to me. I understand the projection format constraints in movie theaters, but at some point it seems possible to just downscale everything to every aspect ratio format. They've done it here, so in theory they could just release all these versions as part of a physical disc set (or stream them all): https://www.odysseymovie.com/explore-formats/ https://www.odysseymovie.com/explore-formats/

ubercore 2mo ago
Originally a lot of HDTV would present SDTV with black bars on the sides. People don't like it.
xdertz 2mo ago
You can also watch 1.43:1 in a virtual cinema in VR.
- MetaWhirledPeas 2mo ago
  Only if the media is published in that format.
- SirMaster 2mo ago
  Pretty much no movies are released in that aspect except like justice league Snyder cut.
mchristen 2mo ago
It can definitely be confusing. For example, traditionally still film cameras used 35mm film, but cinema cameras also used 35mm film. However the cinema cameras capture the image vertically instead of horizontally on the film, otherwise known as a Super 35. Literally the film runs through the camera vertically instead of horizontally. In order to make an image work that is understandable to our brains you either need to do heavy cropping and waste tons of film, or you use an anamorphic lens to "squeeze" more light onto the film. You then have to reverse that when you go to project the film.
ralferoo 2mo ago
> Now we're being told the opposite. The choice of unusual film standards has always been to make the film a bit "special" when viewed in a suitable cinema. The original format 1.33:1 was simply using 35mm wide film (originally 1.35") and after putting sprocket holes on each side, there was 1" of usable width, and someone decided to make a frame 1" x 0.75". The projected image was just scaled linearly. When they started adding audio, the image was shrunk slightly to 22mm x 16mm (the ratio of this image was modified slightly to 1.375:1), and the audio track was just placed between the right hand edge and sprockets. They could use the same projector technology, just with a mask between the film and the lens so that the audio track didn't appear on the screen, and an optical pickup head for the audio that was placed below the mask and lens. As an aside - a silent movie projector has a complicated gear system that advances the film 4 sprockets in a jerk, once every 24 times per second, while before and after that it is fed smoothly (so you have a "loop" of film above and below to take up the slack). You also have a shutter that closes for half the frame to hide the film when it's actually moving, and open when it's stationary. When the audio passes the audio sensor after the bottom loop, it's moving linearly, so the amount of light that can pass through a narrow slit is proportional to the voltage sent to the speaker. Later when stereo was added to films, they just fit 2 audio tracks into the space of one, so mono films would work on stereo projectors and vice versa. And even later, Dolby surround was encoded as a dot matrix pattern in between the sprockets (actually, it was just a film ID and timecode that was encoded) and the audio itself came from the 3-5 CDs that came with each film. But I'm getting ahead of myself. These two standards stuck around for quite a while and then some of the later experimental TV systems started also using this ratio, probably to making filming non-live TV possible / easier as they could use the film process and show it on a TV using a telecine without wasting any of the image space. Once TVs started to become popular, directors started wanting to make their films more special, something that couldn't be experienced the same way on a TV. And so began the arms race on picture formats. For a while 1.66:1 was popular, which used the same projectors as before but changed out the lens for an anamorphic lens which squished the image to make it wider. And soon, 1.85:1 was standardised (with a different anamorphic lens and mask). This was known as "flat" and was used by the majority of films. Some of the higher budget films were produced in 2.35:1, known as cinemascope or just "scope" and so now most cinemas had 3 sets of masks and lenses - square, flat and scope - and could show pretty much everything with a pair of projectors just by swapping the lenses. A few special aspect ratios were tried, but these were usually limited distribution to specialised cinemas, and cropped to a standard size for regular cinemas. In this era, usually the curtains could move to the correct width for each film, or fully closed. 70mm film has been around for quite a long time, but never really caught on as it was expensive to shoot - non standard cameras, roughly 4 times the area of film (and so at least 4 times the cost, but more because demand was lower), and limited where it could be seen as most projectors were 35mm only. It was possible to get projectors that had a swappable gate so you could also show 70mm film, but they were relatively rare - probably less than 10% of cinemas had these. The aspect ratio was almost always 2.2:1, and so while it was narrower than scope format, people would pay extra for the 70mm experience because of the higher quality (and less grainy look). In the 1990s, TVs started shifting to 16:9 (1.77:1) which was a half-way compromise between improving the quality for films (1.85:1 scope doesn't need to be cropped much or only has small bars top and bottom) and leaving masses of unused space for older 4:3 TV broadcasts. However 16:9 was never used for cinema, and more directors switched to 2.35:1 for films after that to keep the "better in cinema" quality. So personally, I don't think 1.43:1 is really any better for 70mm (after all the film is so much bigger, the quality is already improved), rather it's almost certainly been chosen so that it looks different, and much better at cinema. Just as films shown in "letterbox format" on TV with half the screen black looked bad on a 4:3 TV, now pretty much every TV is 16:9, watching a 1.43:1 film on it will have big black bars on the side and detract from the experience. The cinema will be the best place to watch this. So, IMHO, it's all just a marketing gimmick aimed at those that want to pay a premium to see a film as the director intended it.

JimsonYang 2mo ago

7 or 8 of which are in California

qingcharles 2mo ago

18K seems high. I did some tests for Universal once and we pulled 10K from some 70mm IMAX ride prints. 8K was solid, 10K was very borderline.

KaiserPro 2mo ago
I'm trying to remember what resolution we rendered two face for when it went into imax. This was using 32bit renderman, and it was constantly OOM'ing because we were really pushing it. I seem to recall that we rendered out at 7k, even though the optical resolution was meant to be 12k.
- BuildTheRobots 2mo ago
  I wonder if the render resolution was actually determined by the output resolution of the film recorder being used to get the sfx out onto film for display? I can't obviously find a film recorder that offers more than 8k on 65mm/15-perf. As I've not seen anyone else mention it, I feel the need to point out that Digital IMAX (which is the vast majority of screens and showings) maxes out at 4K.
  - KaiserPro 2mo ago
    https://www.awn.com/news/framestore-puts-grave-face-harvey-dent https://www.awn.com/news/framestore-puts-grave-face-harvey-d... Tim webber says it was rendered at 4k. Which contradicts what I remember. If he meant 4k textures that would make sense. 4k textures might have been why renderman kept on OOMing though and we had to tile the render even more. Also I don't know how they printed it back out to film. It might have been sent to hollywood to laser/print out.

dagmx 2mo ago

Thank you very much for the corrections here. As someone else who has professionally worked in the film space, it always irks me when people talk about film in digital resolutions for the reason you mention. I also agree with many of your other corrections but that is the one I wanted to ageee with the most as it’s my biggest pet peeve when I see people claim “film” is equivalent to a given resolution. Anything analogue can be (almost) infinitely resolved but that doesn’t mean it’s going to be effectively good at all those resolutions. Almost nobody thinks of the quality of medium and lenses when making those claims.

SirMaster 2mo ago

I am not even sure why the theoretical resolution matters when they seem to have so much trouble pulling focus on the actors on an old film camera like the IMAX cameras they use to where the footage is fairly blurry in a lot of cases. If they used a 6.5K or 8K digital cinema camera they would get all the advanced autofocus abilities those camera have nowadays to keep the actors sharply focused and would end up with more detail in the end.

kridsdale1 2mo ago
Sensor size. Depth of field is optically different on large frame cell size or sensor size vs 35mm. That camera you reference is not optically equivalent.
- SirMaster 2mo ago
  Sure, but if you watch the Odyssey, you would see how the camera operators struggled to keep focus in some scenes. A modern digital cinema camera would have no trouble with it's advanced auto focus abilities. So the resolution of the film is kinda irrelevant because of that some of the time.

qingcharles 2mo ago

To add another nit-pick to the list, the author confuses 18K as being four times the resolution of 4K. 8K is four times the resolution of 4K. (counter-intuitively to most people as it only measures the pixels in one dimension yet the image resolution is increased in both width and height) Diagram: https://i.pcmag.com/imagery/articles/07toBDd6lpyucCyM0xWrcQv-1..v1569470731.jpg https://i.pcmag.com/imagery/articles/07toBDd6lpyucCyM0xWrcQv...

prmoustache 2mo ago

There is no such thing as resolution in films. There is accutance and sharpness, but it is not resolution.

anfractuosity 2mo ago
Wouldn't line pairs / mm count as resolution.

486sx33 2mo ago

[dead]