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If the shift is greater than this, there may be a problem with the positioning of the image on the printing negative that was supplied to the lab.

You can check the image position to see if it conforms to standard SMPTE 195, which says the image should be "within 0.012 inches" of the nominal horizontal centerline centered between perfs.

One time a guy wanted us to run a 35mm short he had copied from a video source. While it was running, I noticed it was too high, but did not touch the framing knob, because I wanted him to know exactly how it was printed. Of course, he came into the booth telling me to frame up. I told him, OK, but at theaters with few or no operators, it would remain too high. We got into a slight arguement. Luckly, I just happened to have my SMPTE standards with me. First, I proved to him that theaters run 1.85 at 446 x 825. Then I threaded alignment film to prove the framing was correct.

He couldn't belive it. He asked if I could show the alignment film and his film at the same time. So, after warning him about possiable damage to his film (he didn't care) I threaded both a test loop and his film. We could measure how far off it had been printed.

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Like I said, it's either the PA-35 is correct and EVERY other film ever printed is wrong, or everything else is correct and the PA-35 is wrong. Hmmmm, I'm not putting my money on SMPTE here. I can't be the only person who's ever noticed this.

SMPTE Recommended Practice RP 40 specifies location on the film and tolerances for the 35-PA test film:

"The center of the test image shall be within +/- 0.001 in (0.03 mm) of the center of the projectable image area specified in ANSI/SMPTE 195. All projectable image area lines shall be within +/- 0.002 in (0.05 mm) of the nominal dimensions of the test image."

ANSI/SMPTE 195 specifies the horizontal centerline of the image to be exactly between two perforations, or a "nominally equal" distance between them.

So look at your 35-PA (RP 40) film under a measuring (toolmakers) microscope. The horizontal centerline of the 35-PA (RP 40) film should line up exactly between two perforations within 0.001 inches (0.03 mm). If it doesn't, it does not meet the SMPTE practice.

I just looked at a copy of 35-PA-200 that I bought from SMPTE late last year, and it appears to be "on the money" for vertical centering.

One possible reason for the vertical "shift" you see may be that SMPTE usually manufactures 35-PA on film perforated BH-1866, having a 0.073 inch perforation height, and 0.1866 inch perforation pitch. This is because many labs use it for optical printer line-up. Normal release prints are made on a contact printer, using film perforated KS-1870, with a 0.078 inch perforation height, and a 0.1870 pitch.

Are the framelines of the prints that are vertically shifted centered between two perfs? If not, the shift is in the print, and not the 35-PA test film.

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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

Back in the late 80s/early 90s every Universal film was horribly "low" in framing. Why this affected only Universal prints is beyond me. Nothing else from the same lab suffered such problems. Now Universal prints are centered perfectly along with every other film (not counting the PA-35).

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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

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I think you hit the nail on the head...the 35-PA test film is indeed centered (to a much higher tolerence than any release print would ever be).

But why then does Brad (and others) notice that using 35-PA to vertically center the image doesn't work? It is indeed the perforation height (and pitch if it is not .1870"). The intermittent pulls down biased to one edge of the perforation (not the CENTER) thus an error is set up.

Perhaps on the next review of RP-40, we should recommend that standard 35-PA and 35-IQ be made on KS-1870 perforation. If the labs need a test film based on the BH standard then it should be a separate film. 35-PA should be correct for exhibition. I have often questioned the use of BH perforations, even though, technically, 35-PA is a camera negative. It would be best to modify the camera to handle the KS-1870 perforation so it would "correct" for exhibition (now where is Stan's number).

Steve

SMPTE RP 40 is ambivalent on the pitch question. Section 5 says: "A perforation pitch of 0.1866 in (4.74 mm) or 0.1870 in (4.75 mm) is acceptable."

It does specify film perforated in accordance with ANSI/SMPTE 93, which is the Bell and Howell BH perf, and NOT KS.

As I noted, the 35-PA film is used by labs for lineup of (BH) pin registered printers, which would make BH-1866 the preferred perforation for that application. But I agree with you, that the bulk of the film is used for projector alignment, so it would make sense to use KS-1870 perfs. As you note, it may boil down to the ability of Stan D. to modify his camera to use KS pins and 0.1870 inch pitch film.

Let's get this on the agenda for the Projection Technology Committee meeting at ShowEast.

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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

But that thing is so out of date that it's really academic. Get the Sonic Landscapes. They are much more pleasing to the eye and the ear. They are also much more generic meaning you can run them with 'Elizabeth' and also run the smae version with 'Road Trip'.

...and they seem to be framed just fine.

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