2.35? Or is it... 2.39?

[Ranguvar]

Came across this on Wikipedia (http://en.wikipedia.org/wiki/Aspect_ratio_(image)#Previous_and_presently_used_aspect_ratios):

2.35:1 - 35 mm anamorphic prior to 1970, used by CinemaScope ("'Scope") and early Panavision. The anamorphic standard has subtly changed so that modern anamorphic productions are actually 2.39,[1] but often referred to as 2.35 anyway, due to old convention. (Note that anamorphic refers to the compression of the image on film to maximize an area slightly taller than standard 4-perf academy aperture, but presents the widest of aspect ratios.)

2.39:1 - 35 mm anamorphic from 1970 onwards. Sometimes rounded up to 2.40:1[1] Often commercially branded as Panavision format or 'Scope.

Also, from here (http://en.wikipedia.org/wiki/Anamorphic#2.35.2C_2.39.2C_or_2.40.3F):

One common misconception about the anamorphic format concerns the actual number of the aspect ratio itself. Since the anamorphic lenses in virtually all 35 mm anamorphic systems provide a 2:1 squeeze; one would logically conclude that a 1.37:1 full academy gate would lead to a 2.74:1 aspect ratio if used with anamorphic lenses. However, due to a difference in the camera gate aperture and projection mask sizes for anamorphic films, the image dimensions used for anamorphic film vary from flat (spherical) counterparts. To complicate matters, the SMPTE standards for the format have varied over time; to further complicate things, pre-1957 prints took up the optical soundtrack space of the print (instead having magnetic sound on the sides), which made for a 2.55:1 ratio.

The first SMPTE definition for anamorphic projection with an optical sound track down the side (PH22.106-1957), made in December 1957, standardized the aperture to 0.839 in by 0.715 in (1.17:1). The aspect ratio for this aperture, after a 2x unsqueeze, rounds to 2.35:1. A new definition was created in October 1970 (PH22.106-1971) which made the vertical dimension slightly smaller in order to make splices less noticeable (as anamorphic prints use more of the negative frame area than any other modern format) when projected. This new aperture size, 0.838 in by 0.700 in, (1.19:1) makes for an unsqueezed ratio of 2.39:1 (more commonly referred to as 2.40:1). The most recent revision, from August 1993 (SMPTE 195-1993), slightly altered the dimensions so as to standardize a common aperture width (0.825 in) for all formats, anamorphic and flat. At these modern dimensions (0.825 in by 0.690 in—1.19:1), the unsqueezed ratio remains at 2.39:1. [2]

Anamorphic prints are still often called Scope or 2.35 by projectionists, cinematographers, and others working in the field, if only by force of habit. 2.39 is in fact what they generally are referring to (unless discussing films using the process between 1958 and 1970), which is itself usually rounded up to 2.40. With the exception of certain specialist and archivist areas, generally 2.35, 2.39, and 2.40 mean the same to most professionals, whether they themselves are even aware of the changes or not.

So what do you guys think? When I have a claimed 2.35:1 DVD, should I rip it aiming for 2.35:1? Or 2.39:1?

[laserfan]

How do you "rip it" differently from whatever it is? It's whatever conversion you are attempting where you have to adjust, yes?

I have found that movies claiming to be 2.35:1 are often 2.40. Also there are a lot of 2.20 movies which may be mis-identified as 2.35 also.

[Ranguvar]

I rip it differently by encoding to a different resolution, and/or changing the anamorphic flag in the container or video stream.

[foxyshadis]

It's simple: Autocrop, then adjust dar for the pixel aspect ratio and the new dimensions. (or set par directly.) The "standard" is followed with far too many little variations to be reliable.

[laserfan]

The "standard" is followed with far too many little variations to be reliable.I've also noticed that sometimes the widescreen movies aren't perfectly centered vertically in the frame. :(

[Ranguvar]

foxyshadis, give it to me straight :p Should I be aiming for an end result of 2.35:1, or 2.39:1?

[Mug Funky]

if you shoot 35mm with a 2:1 anamorphic lens you'll get both, sort of.

it's a matter of whether you frame for academy (which leaves room on the left of the film for sound) or super35 (which is full width).

if a film isn't centred properly horizontally it's probably because it was framed for academy but transferred "full gate". that would be quite sloppy, so i doubt there'd be any discs like this around. if a movie isn't centred vertically it may have been to leave room for subtitles to prevent them overlapping the picture.

then you've got funky formats like 2-perf, where the footage is non-anamorphic but on half of the film height. one example is "the good, the bad and the ugly", the advantage being you can shoot twice as long on the same amount of film (so you can get about 8 mins out of a 400' camera roll instead of 4). these will finish in 2.35 usually because it typically pre-dates the use of super35 (though this is changing with DI becoming the norm).

[Brother John]

Should I be aiming for an end result of 2.35:1, or 2.39:1?
None of those. Crop, apply 16:9 PAR and your done. Relying on fixed DAR values won’t give you accurate and reliable results because DARs vary from movie to movie. Especially with »2.35« sources I’ve seen anything from around 2.3 to around 2.5. Or in other words: Do not use DAR for SD sources. PAR is all you’ll ever need.

[Wilbert]

Crop, apply 16:9 PAR and your done. Relying on fixed DAR values won’t give you accurate and reliable results because DARs vary from movie to movie.
The DAR is fixed, being either 4/3 or 16/9. The "real aspect ratio" varies from movie to movie.

[SeeMoreDigital]

Just play your DVD movie in a software player and grab a still "image" frame (from a well lite scene). Feed the still image into some imaging software and crop away all the black mattes.

The image pixel frame size of your cropped image will reveal the true aspect ratio of your movie.

[manono]

I agree. What's the big deal? You make it what it is. I also have seen so-called 2.35:1 movies anywhere from about 2.2:1 to about 2.45:1.

[Ranguvar]

Thanks, Brother John. I did not know that :)

[Brother John]

@Wilbert
You're illustrating the problem with the whole concept perfectly. »Display AR« can be so many things that you can hardly use it without a lengthy explanation of what you actually mean. Of course the DAR is fixed. At the same time of course the DAR varies between movies. Oh, and let's not forget, as soon as you crop the DAR changes.
PAR doesn't have any of these issues. That's why I'm so strongly in favour of PAR, even if it might seem less intuitive than DAR on first glance.

@SMD
You can of course use that screenshot method. But why would you want to? Crop-and-PAR gets you the exact same result (apart from rounding errors) and is faster and easier.

[Ranguvar]

Sorry to bring this back from the dead, but do you know of any good aspect ratio calculators capable of applying 16:9 PAR?

This (http://blog.somestuff.org/resizecalculator.htm) one appears to do it, but I can't get it to work right. I always end up with either a ~2.0 or ~3.5 DAR, which is far from the assumed 2.35.

[talen9]

You have to distinguish between NTSC and PAL DVDs too, the PAR differs ;)

There was VideoSizeCalculator from Moitah ... but I can't find it anymore in his restyled home page :confused:

[Ranguvar]

Never mind, found out how :)

[Blue_MiSfit]

What exactly is wrong with not cropping at all, and just encoding the video as-is?

I mean... sometimes when I look at the histograms, there's noise in the black mattes or some goofiness on the edge of the image, in which case I will just crop and then re-apply the same exact mattes...

Just set 16x9 or 4x3 when you mux. I don't get why you would need to do anything else :) Black takes almost no bits to encode. Heck, even if your mattes aren't mod8 the penalty is minor...

~MiSfit