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Author Topic: Cleaning up prints John Wilson Film God Posts: 5438 From: Sydney, Australia. Registered: Dec 1999 posted 04-29-2007 12:57 AM                     Even the CSI guys use FilmGuard? Amazing...  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 04-29-2007 01:03 AM                     Gordon writes, "the warble is the fact that the delay is not set acuratley and one hears the toggling at high speed between analogue and digital". Chris replies, "Really? Because I've noticed it happen when the processor wasn't showing switching between formats. But maybe it was switching too fast for the processor to show. " The warble doesn't have to mean high-speed toggling, no. All 4 digital formats (even CDS!) clock themselves based on the speed of film through the digital sound reader -- this is necessary to maintain sound sync. So if the film is unstable through the digital sound reader (particurly a problem with penthouse readers and platter systems), this instability can translate into wow-ing. You won't hear this on the analog sound, or with a basement reader, because the driven sprockets force the film to constant speed. (Of course you can see wow and flutter in an analog soundhead, but rarely is it as bad as it can be with penthouse readers.) Of course, this has nothing to do with wear on the digital track. If you have a tension problem and a perfectly printed print and a perfectly aligned reader that reads '1' all the time, you'll still hear the wow. --jhawk  |  IP: Logged Chris Slycord Film God Posts: 2986 From: 청주시, 경북도, South Korea Registered: Mar 2007 posted 04-29-2007 01:58 AM                     That's a nice thought but... we use a basement reader. Ones from component engineering.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 04-29-2007 02:00 AM                     Well, maybe you really do have a wow/flutter problem then. But it should affect analog and digital both. Well, perhaps digital may be less sensitive to flutter. Describe more precisely the "warble" you're referring to, the precise conditions under which it occurs, state of the processor, etc. --jhawk  |  IP: Logged Chris Slycord Film God Posts: 2986 From: 청주시, 경북도, South Korea Registered: Mar 2007 posted 04-29-2007 02:21 AM                     I'm bad at describing stuff; my guess is it's probably the delay issue. But next time I see our tech I'll ask him to have a look at it.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 04-29-2007 02:26 AM                     Well, you should get better at it! No time like the present to practice. Having the delay mis-set should not result in variation -- it should result in lipsync problems, and maaaaaaybe weirdness at changeovers. You can try turning off the analog or digital LED so you can guarantee what format you're in and then listen. You can try fiddling with the tension of the running film (apply some more tension with you finger, etc.) and see if you can reproduce the audio defect. Another possibly issue is the air dashpot on the CE readers need adjustment. --jhawk  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 04-29-2007 02:30 AM                     Gordon is correct, but I have also seen a wow from SRD and DTS if there is any bounce in the film feeding into the projector. It shows up worse at the end of a reel when running on reels and when using platters with wobbly rollers. Physical tension going into the projector makes ZERO difference on the tracking ability for either format, but bouncing DOES. There should be no real bob up and down of the film in between the platter and projector on the feed side, or if there is some, it should be slow and steady. You can actually simulate this by bumping the two tension rollers on either side of the sound drum. For a basement reader, bad bearings can produce this effect. (Also if a print is sitting on 6/7 it can be faulting without dropping to analog at all or displaying an "F".)  |  IP: Logged Ron Curran Jedi Master Film Handler Posts: 504 From: Springwood NSW Australia Registered: Feb 2006 posted 04-29-2007 08:00 PM                        Any bounce could be smoothed out by the cleaner before the print enters the DD reader.  |  IP: Logged John Koutsoumis Master Film Handler Posts: 261 From: Melbourne, Victoria, Australia Registered: Aug 2003 posted 05-23-2007 07:57 PM                     I have a print of a current film called "Noise" that's shedding a lot since it got here and it is now sitting on 7-8 and constantly goes to F. Does the shedding effect the SR-D track?This was new print. I don't seem to have any problems with SR-D tracks other prints except for the ones that shed a lot. On the other hand, last week I ran a used season print of "Rabbit Proof Fence" for some school kids and it sat on 3-4 throughout the entire length of the film. Any ideas? The film "Noise" relies heavily on the (5.1)sound mix and I am investigating how to get the SR-D track back online. I have PTR rollers and a Christie FC-1 media cleaner but as yet I have neither up and running. I just found the latter in the bottom of an unmarked box.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-23-2007 08:11 PM                     SRD tracks are damaged in one of two ways. #1 The print is dirty. Prints that are shedding absolutely will cause an SRD track to fail. Just think about it, for SRD to work the system has to be able to see those super tiny dots in between the perforations. Dirt seriously hurts the reader's ability to see the data. #2 The print has scratches in the SRD track, almost always from gate bands with emulsion deposits on them, but also sometimes from a projector with a rough spot somewhere in the sprocket's film path. PTRs won't save you. Neither will a dry media cleaner. FilmGuard is your only chance to save that print.  |  IP: Logged Chris Slycord Film God Posts: 2986 From: 청주시, 경북도, South Korea Registered: Mar 2007 posted 05-23-2007 08:20 PM                     Also, the dry media by itself will certainly work better than PTRs. If you notice the PTR review on this site, a print "cleaned" with PTRs ends up looking dirtier than a print not cleaned at all.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-23-2007 08:44 PM                     Actually Chris, no. The dry media won't help the SRD tracks in one bit. By the time the print gets dirty enough to kill the SRD tracks, a dry media pass won't save it.  |  IP: Logged Chris Slycord Film God Posts: 2986 From: 청주시, 경북도, South Korea Registered: Mar 2007 posted 05-23-2007 09:26 PM                     I'll have to take your word for it since we've never had prints get quite that bad. [edit]And while dry media may not help in this situation, from what I've heard PTRs don't help things (in fact, usually hurt things) regardless of the situation at hand. But that's a bit of a tangent.[/edit] To John: How long have you had the print in question? It seems odd that you'd get a print that dirty really quickly. Unless, of course, your fellow booth people don't care about keeping stuff clean.  |  IP: Logged Cameron Glendinning Jedi Master Film Handler Posts: 845 From: West Ryde, Sydney, NSW Australia Registered: Dec 2005 posted 05-24-2007 10:51 PM                     Chris, the print is shedding, ie white powder is falling off it!!!! Some prints do this. Not as common today, but in the past it has been seen far too many times.  |  IP: Logged Chris Slycord Film God Posts: 2986 From: 청주시, 경북도, South Korea Registered: Mar 2007 posted 05-24-2007 11:38 PM                     I'm well aware what shedding is. I've had prints that shed. I've NEVER had so much shedding that your soundtrack gets covered up by the shedding. The reason I asked about how dirty it was is because I think the whole soundtrack issue likely would've been avoided by cleaning the print regularly. That is, of course, unless there's something more going on that we aren't seeing.  |  IP: Logged

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