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Topic: Buying Test Loops

Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 05-13-2006 06:43 PM

SMPTE is nothing short of a joke as far as its test film department goes. There is simply no excuse for it either in this day of ESTAR base film which does not change dimension sitting on the shelf.

Get your target and sound alignment films from NT Audio Visual. Their sound alignment film, Pink Noise, Tone, and Buzz is the best available period. The pink noise is dead on so be sure to throw your old inconsistant dolby p.n. loops in the trash! I have yet to do a critical comparison of N-T's target and RP-40 but the sample I received looked excellent and is camera original, targeted for aligning systems and filing plates of all common sizes. Contact Edel Adam for purchases, Tel 310.828.1098 .

Mark

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 05-13-2006 07:53 PM

First off...35-PA is not different dimensionally though it is shot on BH-1866 film so it may be used with Telecine machines. I have long claimed that the film should be available in standard KS-1870 as well as BH-1866, depending on one's needs.

The magenta film is known as 35-IQ SMPTE has always packaged it as 100' of B&W and 100' of Magenta. The reason for both films is to see the difference in your projection system between the radiant energy absorbed between the two (B&W soaking up more heat than just the top layer of color film). Both films were shot in the same camera with only the allowance for the perforation difference made. Details are given in the 35-IQ (and 70-IQ) instructions.

One can splice the two together and note the difference in the focus between the two to get an idea of how much heat one is putting into the system...the closer the focus matches, the lower the heat.

As for dimensions...historically, you could not do better than the SMPTE test films...they are camera originals. The to test the camera, the image is photographed forward, then backward, then forward again to verify perfect registration on a period basis.

Why does some test film not show good steadiness? This comes down to how the film is photographed and how it is projected (true for not just test films). Cameras (and Telecines) register off of the perforations. Projectors register off of the edges of the film (laterally). What happens if the film to perforation registration is not perfect? The image moves about. Virtually all of the image unsteadiness in various batches of 35-PA can be attibuted to either mis-slitting or more commonly, skewed perforations. One has to get the film under a microscope to measure the perf to edge relationship in a perf-by-perf fashion.

Generally, the 35-IQ is a much steadier film since the polyester film came into existance. The B&W film tends to have more skewed perfs. One reason 35-PA has been so expensive (and there are many reasons) is the low-volume, high-reject rate and that it is camera original. Note, you don't get to see if your batch is good until after it is all shot and processed.

If you can buy target film for the under $2/ft price...there is a reason...it is not measured nor guaranteed to be anything and most likely a duplicated film. That is okay for checking focus, I guess but it totally and completely worthless as an alignment aid. It would be like trying to use an uncalibrated meter (and you don't know how far it is off) to make adjustments to an electrical circuit.

As to the sound test films...Dolby has definately not been producing worthy products since they went to color. The HF response on their pink noise has been horrible and inconsistant.

About the only thing they are really good for is to check Dolby Digital alignment IF you know how far off your test film is. We resorted to buying 1000' feet of it and then measuring it against reference film to come up with an offset. That has worked out quite well for us. For analog, NTAV is probably the best, after all, they were the last ones to actually make accurate stuff before (they made the twin track Cat. 69).

As for Buzz-Track...the Buzztrack that SMPTE was providing was VERY accurate, more so than it had been as it was shot in the same camera that did 35-PA and it was measured to be correct. Some didn't like the frame overlap that caused noise in the sound...personally, I liked that artifact since it provided a "blip" on both scope traces as well as an audible verification that everything was on and picking up...it was clearly different than the two tones one is listening/looking for.

Steve

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 05-14-2006 08:01 AM

quote: Steve Guttag
As for dimensions...historically, you could not do better than the SMPTE test films...they are camera originals. The to test the camera, the image is photographed forward, then backward, then forward again to verify perfect registration on a period basis.

I would be willing to bet that the NTAV is as good as the SMPTE target and as accurate. It is camera original and is over 2.00 a foot cost but still below the SMPTE stuff. NTAV did their target film because a large national chain was desperate for target alignment film.

As for foreword/reverse camera exposure tests this is nothing special at all, is very commonly done.... sometimes done a bit more often for highly important cameras in use. Its also done on all film prodiction cameras after any repairs are done, before they leave the rental house(say Panavision), before any sort of important film is shot by a production crew. I've also seen it done midway during a feature production on several occasions where live action takes are going to be combined with effects shots. All in all its very S.O.P.

quote: Steve Guttag
One has to get the film under a microscope to measure the perf to edge relationship in a perf-by-perf fashion.

Actually an optical comparator with the right optics and screen overlay is the best for this sort of thing. It can be used to verify the target size/position/skew, etc., and the optical tracks size/position, etc. There are also highly accurate video optical comparators in use that increase the ability to accurately check dimensions even more over the direct view type.

Mark

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 05-14-2006 08:07 AM

It would not surprise me that NTAV would make a good film...that is their reputation. SMPTE's films get expensive partly due to their 100% mark up of whatever source they pay. So something approaching $3.00/foot directly from the source would make sense.

BTW...there is nothing wrong with someone making an exact 35-PA target (without the SMPTE name on it). The RP40 document describes how to make it...that is the purpose of the document.

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John Hawkinson
Film God

Posts: 2273
From: Cambridge, MA, USA
Registered: Feb 2002

posted 05-14-2006 09:52 AM

Instead of speculating, perhaps someone should ask NTAV what their QC process is like?

--jhawk

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 05-14-2006 06:38 PM

No one should take my comments about the quality of the SMPTE products to take anything away from NTAV...in fact NTAV has been the source of some SMPTE products in the past as well as Dolby's only reliable test films in the past.

NTAV is known for making excellent products. Those that have tested the NTAV test films have come back completely with superior results. As for their target...I have not seen it but be sure that if I try it out I will compare it to existing 35-PA or 35-IQ to verify that it is correct.

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Nicholas Grieco
Film Handler

Posts: 1
From: Los Angeles, CA
Registered: Oct 2005

posted 05-18-2006 03:27 AM

I have been informed by Anne Seminara at the SMPTE that 35-IQ is out of production for lack of demand.

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Shawn Jones
Film Handler

Posts: 2
From: Santa Monica, CA, USA
Registered: May 2006

posted 05-20-2006 12:33 AM

Hello All,

I am the Chief Engineer at NT Audio and supervise the production of our test films. Hopefully the following will answer some of your questions regarding the manufacturing and quality control of our products.

The sound test films - NT Buzz, NT Tone, & NT Pink - are all camera original films produced with a laser recorder we developed for our optical soundtrack negatives. Our recorder creates the necessary patterns to produce a postive soundtrack image onto Kodak 2376 B&W sound negative film. This film stock is KS-1870 peforated on the same polyester base as the vision print stocks. We develop the test films in our lab and monitor all of the control aims. Once the film is processed, the dimensions are checked at several points in the reel under the microscope. We then run all of the audio film we sell on our reference optical reproducer and check the necessary sound parameters with an Audio Precision. The goal is to keep any variances to less than 0.1 dB.

We are also finishing development of a replacement RP40 / 35PA film that some of you have mentioned. We created samples prior to Showest that we sent to potential customers for feedback. Based on the comments, we are in the process of making most of the requested changes. The final product will be a camera original film and will be produced on a KS-1870 peforated polyester film. The camera we use is pin-registered with an ACME step movement. The dimensional characteristics will meet the specifications outlined by SMPTE etc..

The goal is to make the product as close as possible to the 35PA/RP40 everyone is using while keeping the cost down in the $2-$3/foot range.

We hope to have the film ready in limited quantities by the first week of June. If you have further technical questions, please send me an email or contact Edel Adams at (310) 828-1098 for any sales info.

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Richard Hamilton
Phenomenal Film Handler

Posts: 1341
From: Evansville, Indiana
Registered: Jan 2000

posted 05-23-2006 09:17 AM

35-PA from SMPTE is available now. Clyde McKinney started making it a few months ago. To get the industry standard, you have to buy it through SMPTE.

quote: Steve Guttag
BTW...there is nothing wrong with someone making an exact 35-PA target (without the SMPTE name on it). The RP40 document describes how to make it...that is the purpose of the document.

This is available also, without crossing any copyright laws. I was thinking of something that said "Hamilton Technical Services" Or "Rick was here", and leaving loops at all the theaters I service!

Rick

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Christian Appelt
Jedi Master Film Handler

Posts: 505
From: Frankfurt, Germany
Registered: Dec 2001

posted 05-23-2006 10:17 AM

Dealers should also be able to get the Schneider Lens Test Film, but I have no idea about the present price. I have used Schneider loops for years.

Full resolution image can be downloaded here:

Schneider Lens test Film

quote:
* MTF test patterns (up to 100 LP/mm) are located at areas that are critical for anamorphic evaluation, as well as for flat lenses.
* The horizontal and vertical grid allow evaluation of lens distortion as well as keystoning and curved screen geometric distortion.
* The high contrast black background reveals excess projector heat problems. It also shows lens chromatic aberration clearly.
* All common formats are shown, with their inch and metric units readily visible, for filing plates.
* The high contrast of this Test Film is ideal for evaluating lens flare and veiling glare.
* Format dimensions correspond to SMPTE recommended practices and standards.

Available in 50, 100, and 200 feet.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 05-23-2006 07:28 PM

quote: Richard Hamilton
Clyde McKinney started making it a few months ago.

Humm.... Clyde seems to be a man of any talent... All I can think of is the pile of el crapo Peavey equipment he deposited here in Salt Lake City.... He sure left his mark here.....

Mark

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Richard Hamilton
Phenomenal Film Handler

Posts: 1341
From: Evansville, Indiana
Registered: Jan 2000

posted 05-24-2006 08:03 AM

Mark, did something bad happen to you at Jordon Commons? [Razz]

I'm not sure he was involved with that theater except for the Mega booth. The Cinema Acoustics wasn't that bad was it?

I left my mark in Salt Lake City last week at the new District 20 plex. Dont say anything bad about it, or I'll have to come kick your ass next time I'm there! [Big Grin]

Rick

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Louis Bornwasser
Film God

Posts: 4441
From: prospect ky usa
Registered: Mar 2005

posted 05-24-2006 08:20 AM

Yep...Peavey is that bad! OK for the carnival or PTA, though. Louis

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Richard Hamilton
Phenomenal Film Handler

Posts: 1341
From: Evansville, Indiana
Registered: Jan 2000

posted 05-24-2006 08:37 AM

quote: Louis Bornwasser
Yep...Peavey is that bad! OK for the carnival or PTA, though. Louis

Really? I've installed their Media Matrix line all over the world in special venues with no problems. I haven't done any carnivals or PTAs yet, but I'd probably just run to Radio Shack for those jobs. [Wink]

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Sam D. Chavez
Film God

Posts: 2153
From: Martinez, CA USA
Registered: Aug 2003

posted 05-24-2006 02:51 PM

WTF is PTA? Like school?

Mark's comment on Clyde is a bit over the line. We all have to make a living and sometimes get our hands dirty doing less than top shelf stuff. I never heard tell of him selling RGM, TECO or such, and we've all gotten dirty messing wih some variant of Ballantyne so chill already.

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