Film-Tech Forum ARCHIVE: SMPTE RP35A and RP110 diffs?

This is topic SMPTE RP35A and RP110 diffs? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Jim Henk (Member # 3628) on 03-31-2013, 01:52 PM:

They both seem to be scope alignment/focus loops. What is the difference between the two?

Posted by Steve Guttag (Member # 268) on 03-31-2013, 05:44 PM:

What are you talking about? What is RP35A?

SMPTE has documents that they publish that can lead to test material that has its own catalog number as a material.

In the case of RP-110...that is the document that describes a test film for anamorphic alignment. The actual test film is 35-AT

This will be analogous to RP40...which is the document that defines/describes the test films called 35-PA and 35-IQ

Note SMPTE is NOT the exclusive manufacturer of test material it defines. In fact, the documents are designed such that others can make the test material. NTAV made their own 35mm target film that pretty much followed RP40 (they added some higher resolution targets too).

http://www.ntaudio.com/services/projection-target.php

Note 35-AT was never really made to the precision of 35-PA (camera original). 35-AT has changed over the years too. It has allowed for magnetic tracks and has had two different centerlines. Most have found its usefulness to a bit more dubious as 35-PA's target evolved to bring about much of the benefits that 35-AT brought to the table.

Posted by Jim Henk (Member # 3628) on 04-01-2013, 12:55 AM:

Yes and no.

Got the first loop name from the Tips section on Focussing Anamorphics:
1. Thread the loop of PA35 test film into the projector, making sure the loop does not hang in front of the lens. Depending on the particular anamorphic you are using, you may have a small thumbscrew, set screw, or a ring collar at the front of the lens. Loosen the locking mechanism so that you can freely turn the outer focusing ring (labeled with measurements, commonly from 20 feet to 150 feet). Note the current setting before changing it for reference.

Sorry about making PA35 into RP35A. Never rush.

As far as the RP110, I'm confused. If the RP110 is only a document, then what's this?

Posted by Steve Guttag (Member # 268) on 04-01-2013, 06:17 AM:

A version of 35-AT test film based on the document RP110. If you procure/obtain a copy of the SMPTE RP-110 document, you'll see how that target was defined.

Posted by Jim Henk (Member # 3628) on 04-01-2013, 08:48 PM:

Understood. Thanks. Didn't know if somehow this was a later upgrade of some kind that people were either recommending or reviling.

Posted by Bruce Hansen (Member # 281) on 04-05-2013, 10:42 AM:

SMPTE test films: SMPTE test stuff