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"Some 35mm KODAK color print film is packaged in compression boxes with individual strips up to 6000 feet long. Each roll of film in compression boxes is in an airtight vacuum bag."

For more information on Kodak's innovative film packaging, see the paper "Packaging Innovations for Motion-Picture Films" by Ann P. Griffen, published in the March 1989 SMPTE Journal.

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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 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Strange thing this morning, rewound (Westrex Tower) Captain Corelli's Mandolin (Deluxe London print), and it is not completely evenly flat throughout therefore forcing the spool wider than normal. Seem to remember this happening two years ago. Large well ventilated projection room with plenty of access to the open air which it was last night. Weather conditions cool evening, rain earlier.
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Greg: Wonderful idea, so much better than on top of the head!

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If the print wound evenly before, and now tends to dish on rewinding, it's possible that the film has stretched slightly along one side (check for excessive tension), has sprocket tooth "roping" or perf damage that prevents it from winding evenly, or has excessive film curl caused by improper humidity. Even a slight difference in curl or film thickness adds up with the hundreds of convolutions in winding a large roll.

Any chance the cool rainy weather has produced humidity much higher than 60%RH?

Hello John,

Running 90 minutes now and everything appears to be satisfactory with perferations & perfectly smooth take-up. Will let you know on Monday how things are.

Many thanks for your help.

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Further to your Questions: posting 05-11-2001
[1] Check for excessive tension.
[2] Sprocket tooth "roping" or perf damage.
[3] Humidity higher than 60%RH? (unable to answer).
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I am extremely relieved to say that there is no sign of any damage to the print,-which is now taking-up & rewinding perfectly smooth (again!). Reel 4 however is a slight exception on rewinding only.

Could the problem last Wednesday have been a curl caused by humidity, and it has 'ironed'
itself out ? I have had these problems before and some shedding. A new copy of Billy Elliot, replacement reel 2 (unsteady) shedded, the other reels didn't, WHY ? Good 2nd hand USA rejuvenated copies (last one was Chocolat) never seem to be a problem, I suppose due to the treatment and cleaning process ?

With Pearl Harbor soon I am considering a humidifier, I would be grateful for any advice as to the efficient size for a projection room measuring 26' x 13'.

Many thanks John for your time and comments.

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Kodak recommends maintaining an ideal relative humidity of 50-60 percent in film handling areas. In this humidity range, processed print film will lie flat, or have just a bit of benficial positive curl. Very dry conditions lead to excessive positive curl, and more static. Very damp conditons lead to negative curl, and the gelatin emulsion becomes softer and easier to scratch and build up hardened deposits in the hot projector gate. Sometimes freshly processed "green" prints have higher moisture content, leading to more focus flutter and "stickiness" until the gelatin emulsion dries out and hardens after a few times through the projector. You may find that you need to use an evaporative humidifier in the winter, and a refrigerated dehumidifier or air conditioning in the wet spring or humid summer.

For your relatively small projection room, any of the larger units sold for household use should be sufficient. But the amount of air drawn up the stack to cool the lamp can be a factor. Providing a separate source of air to cool lamps and power supplies would make maintaining the proper humidity an easier task.

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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 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

The RS website is searchable: see http://www.rswww.com

Thank you both for your kind advice. I’m relieved and pleased to say that the copy is still behaving and taking-up & rewinding smoothly. I have installed around the projection box three 15” fans, and a bucket of water in front of the Tower (with a grill cover on I must mention). I didn’t realize RS stocked humidifiers and will look into today, as I do have an account for my electrical needs.

There is no noticeable evaporation of the water so humidity must be zero, weather is cool & wet here anyway at the moment. Perhaps I should check weather reports daily for any humidity levels ?
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Thanks.

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Accurate digital humidity gauges are relatively inexpensive, and should be used to monitor the relative humidity in the projection room. Again, the ideal is between 50 and 60 percent RH.

The amount of moisture added to the air by a "bucket of water in front of the Tower" is insignificant. Evaporative humidifiers blow air through a moist foam or paper pad, and can add many litres of moisture per day. Do NOT use a humidifier or vaporizer that SPRAYS water mist into the air --- the minerals in the water will deposit as a white powder throughout the projection room (salts are not good for film or electronics).