my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » How often should you rewind prints in storage? (Page 2)

This topic comprises 2 pages: 1  2

Author Topic: How often should you rewind prints in storage? Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 01-13-2004 08:45 AM                        So, why hasn't the SMPTE done a study on polyester base film winding orientation? (Or have they done one already?) It's really confusing to see that several people (all of whose opinions I respect highly) have polar opposite views on which winding orientation causes the least amount of focus drift. Personally, I haven't noticed any difference in focus drift that can be directly attributed to winding orientation. Focus drift is pretty rare with 2kw and under lamps and modern lenses. Old, warped prints are a different story, of course.  |  IP: Logged Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 01-13-2004 08:50 AM                        quote: So, why hasn't the SMPTE done a study on polyester base film winding orientation? (Or have they done one already?) John? I should really join the SMPTE and subscribe to the journal but it's hellish expensive. Being based in the US I couldn't even claim any tax back on it (plus I've just coughed up my AMIA dues this month...).  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-13-2004 09:54 AM                     Another example of base out storage being better is full coat mag tracks. They are almost impossible to get to lie flat on the head block if stored Oxide out and it is polyester support  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 01-13-2004 09:55 AM                     Just unlike Brad...I've yet to have any issues with emulsion-in winding on storage or projection. In fact, at the Uptown in DC we switched to emulsion-in winding to stop (quite effectively) focus drift that was attributed to prolonged projection/storage emulsion out (films tend to play there for 2-3 months). There has yet to be any issue when polyester films came there too so I'm remaining an emulsion-in person for all reel-to-reel projection and out for platter projection. With platters, the diameters are much greater (and progressively so towards the outer reels) and emulsion-out wind presents the base, not the emulsion to potenitally hazardous spining decks or guide posts. Steve  |  IP: Logged Christopher Seo Jedi Master Film Handler Posts: 530 From: Los Angeles, CA Registered: Jun 99 posted 01-13-2004 01:57 PM                     Steve, Just to clarify... you feel that emulsion-in on the feed reel is best for both acetate and polyester? That may be an interesting experiment to try, as I certainly have my share of focus drift problems.  |  IP: Logged Daryl C. W. O'Shea Film God Posts: 3977 From: Midland Ontario Canada (where Panavision & IMAX lenses come from) Registered: Jun 2002 posted 01-13-2004 02:13 PM                        Also unlike Brad and Danny and everyone else down south, I've had much better experience with films stored emulsion in. In fact, I've run into similar focus problems as Steve has with emulsion out winding. quote: It's really confusing to see that several people (all of whose opinions I respect highly) have polar opposite views on which winding orientation causes the least amount of focus drift. The only difference I see is everyone's latitude. Literally.  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 01-13-2004 02:16 PM                        Maybe there's a humidity issue or other climate-control (or lack thereof) factor here. Brad's in the south and likes emulsion out, Gordon's in the north and likes emulsion in. Hmm. Personally, I don't care. I run emulsion out on platters (soundtrack up) and S-wind on reels and don't have problems with most prints.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 01-13-2004 04:25 PM                     To be quite clear...yes...I run emulsion-in on both the feed and take up reels whenever possible. As to climate...that can certainly be a factor. In the Mid-Atlantic area...don't both with tin-plated contacts on connectors...they WILL go noisey. There is probably something to this in the QSC 1400 thread. Steve  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 01-14-2004 01:31 AM                     Scott asks, "So, why hasn't the SMPTE done a study on polyester base film winding orientation? (Or have they done one already?)" I don't think SMPTE does many studies. The SMTPE recommendation for emulsion-in winding is based on work by Kodak's Paul Preo and Eric Yavitz (see paper on this site). One assumes if someone repeated the work for polyester, and it stood the test of time, P3 would look at it. It seems a possible source of confusion is the S-wind issue -- that SMTPE RP39 (for acetate only) recommends not only that you store emulsion-in, but that you do not S-wind but instead wind from emulsion-in supply to emulsion-in takeup. So not only is storage orientation relevent, but whether the film gets S-wound or C-wound during projection, if projecting on reels. Similarly, the same work shows that these effects are a function of hub diameter. So storage and use on 6k reels is much less likely to show an issue than 2k reels. Also use on 5" hub house 2k house reels is dramatically better than 3" or 4" shipping reels. As a wild-assed guess (WAG), I expect that maintaining a consistent orientation is probably more important than which orientation you pick, as long as you are within the humidity constraints for the curl. At low humidity, positive curl is induced, meaning emulsion-in winding is consistent with how the film wants to curl. At high humidity, negative curl happens, consistent with emulsion-out winding. At normal humidity levels, presumably it doesn't matter much (but nominally slight positive curl is the norm, suggesting emulsion-in). --jhawk  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.