This is topic best/worst lab - redux in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by Scott Norwood (Member # 30) on 08-03-1999, 09:16 PM:
 
Just a followup to the old "best/worst lab" thread of a month or two ago: what's everyone's opinion of Foto-Kem? I have a really nice recent 35mm print of theirs here at home; no lab splices in five reels, no scratches, no negative dust. I don't have much experience with Foto-Kem prints; how's the color stability? Hopefully, it's better than Technicolor Hollywood or Deluxe Hollywood...
 
Posted by Ken Layton (Member # 133) on 08-04-1999, 12:50 AM:
 
My friend Tom Moyer shoots his television program, CRITTER GITTERS on Fuji film stock and has it processed at Foto-Kem. They are an excellent lab. Highly recommended!
 
Posted by Christopher Seo (Member # 7) on 08-04-1999, 05:50 PM:
 
I had been wondering about the issue of how a lab can affect color fading. Given today's low-fade stocks, what can a lab do to *decrease* the color stability?

And how can you separate the inherent stability (or instability) of color dyes themselves from a lab's careful (or sloppy) processing, when trying to compare labwork?
 


Posted by John Pytlak (Member # 331) on 08-05-1999, 08:30 AM:
 
Inadequate washing or poor control of the pH of the processed film can affect the long-term dye stability. Residual thiosulfate (hypo or fixer left in the film) must be held to low levels by proper washing of the film prior to entering the dryer --- usually counter-current washes are used. The Kodak Processing Manual H-24.03 details the Methylene Blue Test Method for residual thiosulfate, which labs can run.

Film storage conditions are also very important for long-term film preservation. In brief, storage should be cool and dry. Film should be stored in vented containers so harmful degradation by-products ("vinegar syndrome") don't build up, or Molecular Sieves should be used in closed containers.

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John Pytlak
 


Posted by Scott Norwood (Member # 30) on 08-05-1999, 09:39 AM:
 
Are molecular sieves or ventilated containers necessary for prints on ESTAR-base stock, which supposedly isn't susceptible to vinegar syndrome? Or is it acceptible to store an ESTAR-base print in something like ICC shipping cases? I know about storing acetate-base prints out in the open or in loose cardboard boxes, but I like the idea of storing film in cans to protect it from dust.
 
Posted by John Pytlak (Member # 331) on 08-05-1999, 11:34 AM:
 
Polyester support is much less prone to the hydrolysis (acid and moisture-related degradation of the polymer molecule) that degrades cellulose nitrate and cellulose triacetate base. But the organic materials (e.g., emulsion, dyes, and binders) used in the film still are affected by moisture and can have minute amounts of volatile degradation by-products. Excess moisture also adversely affects dye stability and can cause ferrotyping/sticking. So the use of molecular sieves in sealed-container long-term storage would likely still be beneficial. The same logic would also apply to magnetic media, which usually has oxide and hydrolysis-prone binders coated on polyester support.

Do not use excessive molecular sieve material --- use just enough to get the enclosed atmosphere down to about 30%RH and adsorb any anticipated by-products over the typical 2-year inspection/replacement schedule. You don't want to dessicate the film or magnetic media to bone-dry brittle condition.

Even with molecular sieves, cool or even cold storage is recommended for long-term storage. See SMPTE Recommended Practice RP 131 "Storage of Motion-Picture Films".

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John Pytlak
 






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