Jump to content

2.39 / 2.40 aspect ratios


Nadia McGowan

Recommended Posts

Good morning,

 

I'm currently working on my PhD, and the topic is, as must be obvious, cinematography. I'm having a bit of trouble with aspect ratios.

 

On several occasions, the specs on imdb and American Cinematographer don't match. DP's will say the aspect ratio is 2.40:1 and Imdb will list it as 2.39:1 - there are some instances of confusion between 2.39:1 and 2.35:1, such as in the Harry Potter franchise.

 

Is 2.40 a round-up of 2.39 as I've read in the net? I find this strange because I've read it justified as "2.39 being too difficult to remember". We can remember the exact chroma subsampling and menu configurations and the shutter angle or f-stop of a thousand shots - DPs can remember 2.39 without any problem.

 

At first I thought it could be that they shot 2.35 for 2.39 extraction or the other way round, since the first incongruencies were between those two aspect ratios. But as I go through more and more films, it seems to happen mainly between 2.39 and 2.40.

 

Are they different formats? Is imdb just wrong? What's going on here?

 

Any help is appreciated.

 

Regards,

N

 

 

 

 

Link to comment
Share on other sites

Best book to read is John Belton's widescreen cinema

 

It will explain the History of aspect ratios and widescreen

 

In short

 

Cinemascope started at a 2.55:1 aspect ratio (in the late 50's)

After getting tweaked around to accommodate various sound track configurations most "scope" anamorphic prints had a 2.35:1 aspect ratio

I believe in the late 70's this was tweaked down to 2.39:1 - this was to prevent splices made on the frame lines creeping on screen when projected - the slight crop prevented that.

 

So scope films have been 2.39:1 since the late 70s/80s - thats the standard cinema scope projection. When you see 2.35:1 on IMDB or a DVD case its either from an early film or its wrong. Most people incorrectly call 2.39:1 scope - 2.35:1 for historical reasons even though its wrong.

 

2.40:1 isn't an actual aspect ratio - its just 2.39:1 rounded up, if a film is labelled 2.40:1 chances are its actually 2.39:1.

Saying "two four oh" is slightly quicker then "two point three nine" - when a DOP uses 2.40 she knows its not actually 2.40:1 or 2.4:1 - its just a short hand. Whats printed or on imdb is created by marketing peeps and graphic designers - they won't understand the specifics of aspect ratios.

 

Plenty of film people say "two three five" even when they know its "wrong", but it flows off the tongue in English in a nice way. Or we could stick with Flat and Scope to describe the main two ratios.

 

The aspect ratios listed on IMDB can be wrong at lot of the time and in the early days of widescreen (50s, 60s) there were many AEs in use: 1.66:1, 1,70:1, 1.75:1, 1.85:1, 2.0:1, 2.21:1, 2.35:1, 2.55:1, 2,65:1, 2.76:1 etc..

 

But late 70's early 80's onwards 99% of cinema content is either 1.85:1 flat or 2.39:1 scope

 

Of course the aspect ratio flexibility digital and digital projection has offered means - we are moving towards more and different ratios - e.g imax, 2:1 etc...

  • Upvote 1
Link to comment
Share on other sites

  • Premium Member

with DCP on normal screens it is still the choice of whether to letterbox the oddball aspect ratio inside the 1.85 "flat" format OR to pillar box it to 2.39 "scope" format.

projectionists may be lazy and/or uninformed so even if the dcp spec would allow other aspect ratios it is best to stick with the standard ones...

 

cinema screens tend to be natively 2.39:1 shaped and pillar boxing 2.35 into it would just annoy the audience without bringing anything extra to the viewing experience (very slight difference between aspect ratios so they are virtually the "same" but the unused screen area would disturb some people) . projectionists might also just zoom the image a little bit so that it fills the sides of the screen completely and thus the top and bottom would be cropped a little which would annoy the director and DP even though the audience would be happy :P

Link to comment
Share on other sites

with DCP on normal screens it is still the choice of whether to letterbox the oddball aspect ratio inside the 1.85 "flat" format OR to pillar box it to 2.39 "scope" format.

projectionists may be lazy and/or uninformed so even if the dcp spec would allow other aspect ratios it is best to stick with the standard ones...

 

cinema screens tend to be natively 2.39:1 shaped and pillar boxing 2.35 into it would just annoy the audience without bringing anything extra to the viewing experience (very slight difference between aspect ratios so they are virtually the "same" but the unused screen area would disturb some people) . projectionists might also just zoom the image a little bit so that it fills the sides of the screen completely and thus the top and bottom would be cropped a little which would annoy the director and DP even though the audience would be happy :P

Quite "Grand Budapest Hotel" - had 1.37, 1.85 and 2.39:1 segments all within a 1.85:1 digital container.

Link to comment
Share on other sites

  • Premium Member

Keep in mind that 35mm anamorphic film projection has a constant 2X desqueeze.

 

Originally CinemaScope, which uses 2X anamorphic lenses, was going to use the Full Aperture of 4-perf 35mm, which is 1.33 : 1, creating a 2.66 : 1 image once unsqueezed, to compete with Cinerama, which had a 2.66 : 1 ratio. Like Cinerama, this would mean the sound would be run separately on mag rolls interlocked with the projector. This idea was ditched in favor of putting four tiny magnetic stripes on the 35mm print, and using special print stock with smaller sprocket holes to make room for those stripes, which was on each side of the image. This reduced the usable area of the 4-perf 35mm frame from 2.66 : 1 to 2.55 : 1.

 

Then in 1957, it was decided to ditch the mag stripes in favor of the standard optical track on the left side of the print, shifting the center of the projected area over to the right. The dimensions of the anamorphic projector gate became .839" x .715" = 2.34685... : 1 once unsqueezed, commonly called 2.35 : 1.

 

Then in 1971, it was decided to reduce the height of the projector gate to hide splices along the frame lines better. The new gate was .838" x .700" = 2.3942857... : 1 once unsqueezed.

 

Then in 1993, it was decided to standardize the width of all sound formats to .825", so the new anamorphic gate was .825" x .690" = 2.391304... : 1 once unsqueezed.

 

4K DCP scope specs are 4096 x 1716 pixels = 2.386946... : 1.

 

Sometimes I say "2.40" just to be able to say that the unsqueezed image is 1.20 : 1, making it simpler to describe.

Link to comment
Share on other sites

  • Premium Member
Then in 1971, it was decided to reduce the height of the projector gate to hide splices along the frame lines better.

 

I’ve always found that ridiculous. CinemaScope productions generally are of a volume that allows a little bit more elaborate negative assembly and interpos. making. Like 16mm it can be made up in two bands to make splices disappear. No, one would rather waste image surface.

Link to comment
Share on other sites

  • Premium Member

Oughtn’t. Cutting tools need to be asymmetrical, black spacer overlaps and hides splices. The end of the black spacer should lie in the middle of the frame line. Duplicator’s aperture should block out frame line additionally so that it will turn out all black on release prints. I wonder why it works with 16mm film but not with 35. Have had flashing prints myself and that’s the reason why this thing annoys me. If I find out that early CinemaScope prints don’t flash, I pour my anger over the industry. Which will laugh at me.

Link to comment
Share on other sites

Oughtn’t. Cutting tools need to be asymmetrical, black spacer overlaps and hides splices. The end of the black spacer should lie in the middle of the frame line. Duplicator’s aperture should block out frame line additionally so that it will turn out all black on release prints. I wonder why it works with 16mm film but not with 35. Have had flashing prints myself and that’s the reason why this thing annoys me. If I find out that early CinemaScope prints don’t flash, I pour my anger over the industry. Which will laugh at me.

I assume the problem arises when frameline splices are attempted, rather than the wide splices (wide, that is, compared with the frame height) used in 16mm A/B.

Link to comment
Share on other sites

  • Premium Member

Please don’t blame the projectionists. We have ISO 2939 that defines picture image area on prints, position and dimensions. We have ISO 2906 and 2907 to regulate the maximum projectable image area on camera originals and fresh prints. Projectionists can’t compensate all the time for variations that come from cameras. The tolerance on the vertical image centering is 0.008" or 0,2 mm. It is the duty of the lab to produce prints within specs but if the producer doesn’t care about vertical centering with the cameras they use, the lab people would need to smooth out too big differences on precision printers. The projectionists aren’t responsible for the often oblique geometry of theatres complicating matters, either.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...