Film-Tech Forum ARCHIVE: Emulsion-in Emulsion-out and SMPTE RP39

This is topic Emulsion-in Emulsion-out and SMPTE RP39 in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Antonio Marcheselli (Member # 373) on 03-11-2005, 02:26 PM:

Hi everyone

I read few posts about which is the correct way to wind the print on platters, many of you prefer to wind it emulsion-out (soundtrack up) for many reasons.

Few days ago I was on Kodak website reading the 2383 and 2393 print features and I found this:

quote:
For optimum projection focus performance, processed prints should always be wound emulsion-in, in accordance with SMPTE Recommended Practice RP 39-1993

Now, I read on many posts, basically from John Pytlak, that Rp39 is referred to Triacetate prints only and that there are still no tests made on Polyester prints that can prove which side is better...

Is something changed? Has RP39 updated for Polyester prints?

Bye!
Antonio

Posted by John Pytlak (Member # 331) on 03-11-2005, 10:23 PM:

No, SMPTE RP39 is still based on the characteristics of triacetate base. The curl of polyester is somewhat more humidity dependent than triacetate, because triacetate base absorbs more moisture. As others have posted, with polyester prints, use whatever works best with the equipment and humidity conditions you work with.

Posted by Antonio Marcheselli (Member # 373) on 03-12-2005, 10:00 AM:

Thank you John!

Have ALL Kodak prints got the edge number that indicate the print type?

Does someone know if I can say that the print is from FUJI if no numbers is printed on the edge?

Bye

Antonio

Posted by John Pytlak (Member # 331) on 03-12-2005, 10:19 AM:

Kodak has been printing the full film batch identification (magenta-colored edgeprint) on Kodak VISION Color Print film for about the last 5 years. Kodak worked closely with the digital sound vendors and labs to be sure its magenta edgeprint did not interfere with reading digital tracks. Fujifilm followed with their magenta edgeprint a few years later. Last I knew, Agfa-Gevaert (AGS) still prints a dark yellow or brown ID between the perforations, and it does not carry full tracking information. If there is no edgeprint at all, it is "off brand" film.

Posted by Antonio Marcheselli (Member # 373) on 03-12-2005, 10:24 AM:

Uhm, very interesting!

I just checked many of my copies, I didn't noted the edgeprint of Fuji before. Does AGFA makes Film prints too? Does "no brand" prints exist?????

Bye
A

Posted by John Pytlak (Member # 331) on 03-12-2005, 12:20 PM:

Yes, Agfa-Gevaert still makes color print film and sound negative film, but they stopped making motion picture camera films years ago. Kodak still makes a full line of color and B&W motion-picture products, including the small volume products used for mattes, titling, internegatives, B&W separations, etc.

In addition to "no brand" films without edgeprint ID, mistakes do happen and the edge printer can on rare occasions fail to print the edgeprint. Before Kodak developed digital-compatible magenta edgeprint, labs sometimes ordered print film without edgeprint for features having Sony SDDS tracks to avoid any chance of the old yellow-brown edgeprint interfering.

Posted by Antonio Marcheselli (Member # 373) on 03-12-2005, 01:32 PM:

Thank you John

I understand the SDDS initial issue! So, if I correctly understanding, manufacturer that are making film print now are Kodak, Fuji and Agfa?

Bye
A

Posted by John Pytlak (Member # 331) on 03-12-2005, 02:42 PM:

Those are the "big three".

Posted by Antonio Marcheselli (Member # 373) on 03-19-2005, 12:07 PM:

John

"AGS" on the edge means that the print comes from Agfa?

Ciao
A

Posted by Aaron Sisemore (Member # 145) on 03-19-2005, 02:02 PM:

quote: Antonio Marcheselli
"AGS" on the edge means that the print comes from Agfa?

Yes. Agfa changed to placing the 'A G S' printing on the extreme edge of the film around the time of Dolby SRD tracks becoming popular (Agfa used to put their edge markings in between the perfs prior to then). Of course, 'A G S' stands for Agfa Gevaert Safety.

-Aaron

Posted by Antonio Marcheselli (Member # 373) on 03-19-2005, 05:46 PM:

Thanks

Posted by Darren Briggs (Member # 1071) on 03-19-2005, 06:12 PM:

i would say if running on a platter go emulsion out, (sound up on the deck) this helps prevent wraps a little and if a miss aligned roller is feeding the film onto the deck the base will be scratched not emulsion (not that nay part of any film should ever have to run on a bad roller and get scratched)

Darren

Posted by Leo Enticknap (Member # 534) on 03-23-2005, 03:42 AM:

quote: Antonio Marcheselli
Have ALL Kodak prints got the edge number that indicate the print type?

You can determine the base type without any edge number. Triacetate is a lot thicker than polyester and has a distinct 'solventy' smell (especially when you first open the can), even if it's a newish element without any discernible VS. Polyester is extremely thin and generates static electricity as it's wound, very easily. The foolproof test is to take a section of film at the hear and tail of a reel (not from the picture section!) and try to pull it apart. If it tears, the base is nitrate or acetate; it it stretches slightly, but will not come apart however hard you pull, it's polyester. Polyester film simply cannot be torn with your bare hands.

Posted by John Pytlak (Member # 331) on 03-23-2005, 05:34 AM:

quote: Leo Enticknap
Polyester is extremely thin and generates static electricity as it's wound, very easily.

Kodak VISION Color Print Film has a transparent conductive anti-static backing layer that quickly dissipates any static charge, so "shocks" during winding have essentially been eliminated. Kodak VISION Color Print Film ESTAR base is 0.0047 inches (120 micrometers) thick. 35mm print triacetate base was nominally 0.0056 inches (142 micrometers) thick.

Another way to identify polyester base is to view it between "crossed polarizers". If you take two polarizing filters and orient them so they block light passing through them, look at a clear piece of print film placed BETWEEN the two polarizers. Triacetate base will have little effect, but polyester will change the polarization and let some light pass due to its birefringent properties. When polyester base is manufactured, the hot plastic is extruded in a thick sheet, then a huge machine is used to "stretch and tenter" the sheet, orienting the plastic molecules to give the film base it's strength (kind of like pulling taffy). These oriented molecules have birefringent properties.

Posted by Mitchell Dvoskin (Member # 751) on 03-23-2005, 07:27 AM:

but polyester will change the polarization and let some light pass due to its birefringent properties.

Does this imply that polyester film can not be used for polarized 3D?

Posted by John Pytlak (Member # 331) on 03-23-2005, 02:55 PM:

quote: Mitchell Dvoskin
Does this imply that polyester film can not be used for polarized 3D?

It works fine in polarized 3D systems. Kodak VISION Color Print Film on ESTAR base is routinely used for 3D prints showed in polarized systems (e.g., all the prints for "Polar Express").

The birefringent properties of polyester base are only apparent when the film is BETWEEN the crossed polarizers, which is not the situation in 3D polarized projection.

Posted by Darren Briggs (Member # 1071) on 03-24-2005, 12:58 PM:

the polarizing filters are after the film so doesn't matter ehat happens to the light before it