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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 :)

2.40 to 1 vs 2.35 to 1

Linda Barzini

Linda Barzini

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I frequently see both of these ratios. Lately, it seems I see more people talking about 2.35 to 1, but what is the practical difference? Obviously, they are both really close, but is there a preferred format for final delivery for a feature? Are there any definite times to use one or the other?
 
It's fairly subjective in practice at this point. 2.40:1, 2.39:1, 2.37:1, and 2.35:1 are all considered widescreen. RED's WS format is 2.37:1 to allow for a small crop to 2.35:1 or 2.40:1, or just simply leaving it as is at 2.37:1.

Personally I like 2.40:1, but that's just what my jam is for widescreen in these modern times.
 
2.35 hasn't been a SMPTE standard since 1970 when the specs were changed to allow for a little space between the top of one FILM frame and the bottom of the next frame to allow for splices in projection. 2.40 is not actually a format either, it's a generalization... rounding up the number of 2.39:1... The DCI standard for widescreen IS in fact 2.39:1 (2048x858 for 2K and 4096x1716 for 4K delivery)...

That Dragon 6K is 3792x3160 (1.2) is because it allows for an unsqueezed 2.40:1 image that can be slightly cropped to a 2.39 delivery in post.
 
Technically, 35mm scope print projection hasn't been 2.35 since the early 1970's when the standards were changed -- the height of the projector gate mask was reduced slightly to hide frame line splices better, making the shape slightly more widescreen, around 2.39. The standards were changed again in the early 1980's to make both flat and scope prints use a common width for their masks, but the proportion for scope remained around 2.39.

Current DCI specs for 2K scope projection is 2048 x 858, which is about 2.387 : 1.

Of course for letterboxed HD of scope movies, you can choose 2.35 or 2.40.

(Chris beat me to it...)
 
Christopher Probst said:
2.35 hasn't been a SMPTE standard since 1970 when the specs were changed to allow for a little space between the top of one FILM frame and the bottom of the next frame to allow for splices in projection. 2.40 is not actually a format either, it's a generalization... rounding up the number of 2.39:1... The DCI standard for widescreen IS in fact 2.39:1 (2048x858 for 2K and 4096x1716 for 4K delivery)...
Click to expand...
Christopher and David Mullen have it exactly right. For home video, I've always nagged studios to transfer at 2.40 because it gives us a sliver more room top and bottom to obscure splice lines from dodgy film elements. Otherwise, we'd have to zoom in on all four sides, which is a terrible compromise. The negative splicing got better as the 1970s went on. And there were 2.55 anamorphic CinemaScope features prior to 1958 (placing picture in the area normally reserved for optical tracks).

The side of the anamorphic Panavision lens barrel does have "2.39" etched on it, last time I checked. But in truth, we'll just transfer whatever the client wants. 2.39 is indeed the DCI standard for projection. If you provide some distributors with 2.37 or 2.35, they may have the right to reject it depending on the nature of the contract.
 
The thing is that "2.35" has become such a common label that just because it says "2.35" doesn't mean it might not actually be something more like 2.39.

I once went to a screening of one of my scope movies at the Kodak headquarters and the old projectionist there proudly told me he had just cut a new 2.35 projector mask for the projector; I didn't have the heart to tell him that it hasn't been 2.35 since the early 1970's.
 
Unfortunately, I'm old enough to remember this.
2:40 was primarily seen with 35mm prints that had 4 magnetic stripes on the print for the audio tracks. (AKA "Cinemascope" mag prints)
This allowed for a slightly wider image area, and thus, slightly wider aspect ratio.
The cameras, mostly Mitchells, had full frame apertures, but the ground glasses in the viewfinders were marked to exclude the sound track area for composing.
The fact that the full frame aperture was used meant that part of the extra amount of image recorded was used for the 2:40 aspect ratio, and it was contact printed all the way to the "Cinemascope" mag striped release print, which had a slightly different image area than standard academy.
 
The original CinemaScope print with "CS" perfs and mag stripes on the left and right side of the print had a 2.55 : 1 aspect ratio with the image centered on the print as with Full Aperture / Silent. It then become 2.35 : 1 when they switched to the standard optical track on the left side, shifting the center of the image to the right as with Academy and 1.85. It was all contact printed though, the groundless in the viewfinder was just adjusted for the new center and eventually the lens was shifted over to the new optical center.

The original plan for CinemaScope was to project Full Aperture and thus get a 2.66 : 1 aspect ratio (2X 1.33 : 1) with the sound run in interlock with 35mm full coat mag ala Cinerama.
 
Having paid my way through film school as a projectionist I remember that there was a big difference between shooting aspect ratios and projection ratios. The ap ratio for scope cameras was I believe 1.19:1 with a 2X squeeze. So you could possibly have a ratio of 2.38:1. But in our 5 projection booths we had aperture plates anywhere from 2.35:1 to 2.4:1 but so many were filed to abstract ratios. (and this was at USC) Also projection masks on screens were sometimes arbitrary. Many theaters had a fixed 2.0:1 screen. So 1.85:1 films and scope films were all fitted to that 2:1 screen. "Oh the Horror, the Horror"
 
I use 2,35:1 on all my widescreen projects. I think that's the sweetspot for widescreen nowadays due to the fact that most people use smaller screens. 2,40:1 is too wide for me. I like the 16:9 format, always looks good on a large high res screen (look at Better Call Saul), so when going wide I feel that 2,35:1 is better for composition and the viewing experience on anything outside the silver screen.
 
For everyone's amusement, here are images of 35mm magnetic striped print stock.
Small CS Cinemascope perforations, and an offset image center, not quite all the way to academy offset.
Hmm. "Insert image" feature does not seem to be working for me.


 
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I appreciate the history behind these aspect ratios, but is there an expected aspect ratio for final delivery. If someone wanted to do a widescreen feature in 4k or 6k, would the main distributors expect 2:35 to 1 or if it is slightly different does it matter? Can all modern projectors manage any of these widescreen ratios? Is one safer than another?
 
DCI standards are set, so anything outside of them would require letterboxing of some sort, which some distributors can object to, which is why it is safer to stick to the standards. For a 4K DCP of a "scope" movie, it would be 4096 x 1716 pixels (which comes to 2.3869463 : 1) -- if you wanted it to be 2.35, you'd have to put thin black borders on the sides of the 4096 x 1716 file (it would be a 4033 x 1716 pixel image inside a 4096 x 1716 pixel file).

For an HD release on home video, HD is 1920 x 1080 pixels so it matters less to a distributor if you want to letterbox to 2.35 versus 2.39, etc.
 
When I'm grading I go with 2.39:1 (2048x858). If I'm then delivering for HD I just export as HD, Resolve adds the letter boxing automatically and does a flawless job of scaling.

I'm a younger guy, so to me the historic standards (2.40 and 2.35) matter a lot less, what matters to me is: if it goes to DCP, will it be pixel-to-pixel flawless? 2.39:1 is that way to go IMHO (and you can bet audiences can't tell the difference).

EDIT: not that there's not room for lots of different aspect ratios in this world, really only referring to stuff shot anamorphic/framed for scope.
 
In theory, but in practice most theaters' screen masking and projection throw is set-up for 1.85 and 2.39 movies, so other ratios have to work within those parameters. The basic idea with the DCI specs is that 1.85 uses the max possible height (1080 for 2K) and 2.39 uses the max possible width (2048 for 2K), hence the "container" being 2048 x 1080.

From:
https://en.wikipedia.org/wiki/Digital_Cinema_Initiatives
Quote:
Even though it specifies what kind of information is required, the DCI Specification does not include specific information about how data within a distribution package is to be formatted. Formatting of this information is defined by the Society of Motion Picture and Television Engineers (SMPTE) digital cinema standards.

So the DCI specifications for 1.85 and 2.39 come from SMPTE (which you linked to as well).
 
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