Film-Tech Forum ARCHIVE: aspect ratios and equipment requirements

This is topic aspect ratios and equipment requirements in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Dave Ganoe (Member # 53) on 09-15-2000, 01:35 PM:

The theatre that I help out with is thinking of renting some older films for some special shows and the catalog with the films states that aspect ratios of 1.33:1 require a special lens and aperature plate. Anyone have some suggestions as to what we could do? HOw can you tell if a lens is for this ratio? Would another aperature plate give satisfactory results? Thanks.

Posted by John Pytlak (Member # 331) on 09-15-2000, 02:24 PM:

Sound prints prior to the early 1950's almost all used the "Academy" format, which has an aspect ratio of 1.37:1. Standard SMPTE 195 defines the projected image area of this format as 0.825 x 0.602 inches (20.96 x 15.29 mm).

To choose the proper focal length lens needed to fill the height of your screen for this format, use the lens calculators provided on Film-Tech, or by the lens manufacturers. Schneider and IscoOptic provide on-line calculators:
http://www.schneideroptics.com/theatre/desprodn.html
http://www.iscooptic.de/english.html

You will need to know the throw, film format, image desired on the screen, etc. The Schneider software even allows you to factor in projection angle to calculate keystone distortion.

In a pinch, many theatres use the prime lens from the "scope" format with the appropriate 1.37:1 aperture. It will not fill the height of the screen, but you will maintain the original composition of the images. If you can, adjust your black masking to properly frame the image. Because of the lesser magnification, you will find that you have a brighter image than current widescreen formats, so you may need to reduce light level to get the SMPTE aim of 16 footlamberts.

IMHO, any theatre that shows more than a few "classic" films each year should consider equipping themselves to properly project the format to fill the height of their screen.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Ian Price (Member # 14) on 09-15-2000, 06:32 PM:

When we opened our cinema in January we had only the 1.85:1 lens and Scope or 2.35:1 lens. We then did a classic film in 1.37:1 and we didn't quite know what to do.

We took the base lens off of the scope and used that with the scope aperture plate and it worked ok. We were a little undersized and the edges were rough.

The next batch of classic films came in at 1.37:1 so we called our cinema supplier. He had a used lens that was 5mm smaller than our scope back up and that made the picture a bit bigger. We have been using that ever since. We still use the scope aperture plate as well. The lens had damaged threads so it couldn't be used as a scope back up and we were charged $150.00 for it. Not bad.

Our next goal is to find a couple of 1.66:1 lenses. I guess we will have to break out the lens calculator and the aperture files.

Posted by Harry Robinson (Member # 265) on 09-15-2000, 11:33 PM:

I've got to put in a good word for one of our local Regal houses (The Green Hills Cinema in Nashville). They are showing Gimmie Shelter this week. Their regional tech came out with the appropriate lens and aperture plate for 1.37:1. The booth guys are having a blast with it. They're also getting a lesson in basic rock and roll history. I'll be looking at it tomorrow, but they say the 16mm to 35mm blowup looks great.

By the way. they're also showing Raiders of the Lost Ark in their big room this week.

Posted by John Wilson (Member # 269) on 09-16-2000, 01:26 AM:

OK, so everyone knew I would jump in here...

Why are they running Raiders? A special event perhaps? Is it in 35mm or 70mm and what is the print like?

Enquiring minds want to know.

PS: Has anyone heard if Stevie baby is planning a theatrical re-issue of Raiders for its 20th anniversary next year? (Let's hope he doesn't digitally remove the guns...that would spoil a good gag!)

Posted by Tim Reed (Member # 137) on 09-16-2000, 07:14 PM:

Humm, I thought they were reissuing that picture for an anniversary?

Anyhow, I'm still waiting for "Raiders of the Lost Arc".

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Better Projection Pays!

Posted by Leo Enticknap (Member # 534) on 09-18-2000, 10:45 AM:

The other use for a 'scope backing lens is for the so-called 'early sound' or 'full height' ratio (of approx. 1:1.15, depending on the printer matte), which was used for sound-on-film productions between its introduction in 1927 and the standardisation of the 'Academy ratio' in (I think) 1933.

These are films which were shot using a camera with a full-gate silent aperture, but which had a strip masked off the left hand side when printed in order to fit the soundtrack on. It doesn't apply to films that were originally sound-on-disc because the frames were full-gate silent, and modern re-releases tend to be optically reduced to Academy (thus preserving the full frame area).

Some early sound films look OK in Academy - because theatre masking systems weren't adjustable in those days, cinematographers tended to frame their shots bearing in mind that the top and bottom of the frame might end up being masked off. But other films, especially European ones from the early '30s, really do need the full height screen to avoid noticeable cropping. I find it useful to have the anamorph on a bracket rather than screwed into the front of the backing prime, so that the prime can be used separately with a minimum of fuss if necessary.

Posted by Martin Frandsen (Member # 74) on 09-21-2000, 03:23 PM:

A theater over here was running 'singin in the rain' in 1.85, they could not even run 1.66.

Posted by Florian Pausch (Member # 708) on 09-22-2000, 03:26 AM:

When we screened the restored Laurel & Hardy films three years ago, the distributor was really astonished about our huge success (cropped openair every night). He had shown the films in some multiplexes around Austria, with more or less no income. No wonder, some prints were pencil- marked: "mono, 1:1,85" - they had screened just 1/3 of the whole picture !!!

best wishes from Vienna,
Flo