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#1 P S Manushpsnandan

P S Manushpsnandan
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Posted 16 October 2007 - 01:12 AM

Hi
Am a first ac from india, i have been working with super 35 format in my last two feature projects, we use a 235 ground glass and use a universal gate to record the whole negative and later adjust frame in the post when needed, am quite clear about this,but when we shoot adfilms which are meant only for television, we use the same universal gate and the ground glass depends on the director,we hav used fullgate,66 or 85 according to the purpose, my doubts start here.
1)Is the universal gate different for a normal 35 and super 35, since the super35 occupies sound area also?
2)Is there separate 1:1.85, 1:1.66 groundglasses for super 35 and normal 35?
3)Is there a major difference betwen 1:1.85 and 235 in terms of aspect ratio?
4)Is the universal gate different for 3perf?
5)what is univisium exactly?
It would be great if someone could clarify my doubts.

Regards
Manush
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#2 David Mullen ASC

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Posted 16 October 2007 - 01:58 AM

DON'T CROSS-POST THE SAME QUESTION TO MULTIPLE SUBFORUMS

Here's one diagram I did to show the different apertures, although "matted widescreen" (like 1.66, 1.85, etc.) does not normally used a matted gate, it's just composed for later matting during projection:

Posted Image

Super-35 is essentially the same thing as Full Aperture / Silent Aperture. You expose an image across the full width possible in 35mm, just as you did in the Silent Era, from sprocket row to sprocket row. The maximum height and width in 4-perf creates a 1.33 : 1 image (4x3).

Then there is Academy Aperture (1.37 : 1), in which the center of the frame is optically offset because of the soundtrack that will be added during printing on the left side. Widescreen projection formats (1.66 to 1.85) matte Academy further top & bottom during projection.

So for a camera set-up for standard "sound aperture" 35mm (Academy / matted widescreen / anamorphic widescreen) the optical center of the frame is offset, so the lens is offset relative to the gate.

However, what's confusing to many people, is that many cameras set-up for standard 35mm expose the Full Aperture (Super-35) gate -- only the lens is off-centered. The idea is that it doesn't matter if the Super-35 area gets exposed because the soundtrack is going to cover-up the left edge of the print. There are a few camera though (like older Arri-2C's and III's) that sometimes have a 1.37 Academy gate and thus don't expose Full Aperture. However, most modern sound cameras expose Full Aperture. This way, it is easy to convert the camera to Super-35 just by moving the lens position over to recenter it.

Anamorphic widescreen uses a camera lens with a 2X squeeze to expose an image onto a 1.20 : 1 gate; when the image is expanded back out by 2X, the aspect ratio becomes 2.40 : 1 (I'm rounding everything up; these days, anamorphic projection is 2.39 : 1 but often still called 2.35 : 1.)

Obviously, the difference between a rectangle that is 1 x 1.85 in proportions compared to a rectangle that is 1 x 2.35 in proportions is that the 1.85 rectangle is less wide, is squarer, compared to the 2.35 rectangle.

When shooting Super-35 (Full Aperture) you can compose for cropping to whatever aspect ratio you want. So yes, there are groundglasses for composing all these aspect ratios in Super-35 and there are groundglasses for composing them in standard 35mm.

3-perf photography is always Full Aperture (image is exposed sprocket row to sprocket row, optically centered between the rows). 3-perf Full Aperture is 1.78 : 1. You can compose within that for cropping to other aspect ratios.

Univisium is a 3-perf 35mm format with a gate that is cut to expose a 2.00 : 1 (2x1) image. Technically, it is also a 25 fps format.
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