This is topic VOTE NOW...PTRs vs. Media Cleaners in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=000146
Posted by Brad Miller (Member # 2) on 07-17-1999, 01:09 AM:
Since this forum requires valid email addresses for posting, this should be reasonably accurate and not just one guy reposting over and over to sway the vote.What does everyone get better results with, PTRs or dry web media cleaners? All answers need to be in reference to the 35mm format only to be fair.
I'll start with my vote for media cleaners.
Posted by Joe Redifer (Member # 3) on 07-17-1999, 03:13 AM:
Media cleaners win.PTRs actually make the film DIRTIER over time. I don't personally think that a dry media cleaner does a whole lot of good by itself, it is still leaps and bounds better than PTRs.
Posted by Ken Layton (Member # 133) on 07-17-1999, 03:37 AM:
Media cleaners---Yes!
Posted by Erika Hellgren (Member # 22) on 07-17-1999, 11:55 AM:
Actually, I've never been entirely impressed by either PTR's or media cleaners (which is why I'm waiting with baited breath for FilmGuard), but if I had to choose between the two ... I guess I'd go with media cleaners. The concept just makes more sense to me than PTR's. You know what PTR's are really good for though? Removing lint from your clothes.
Posted by Mike Blakesley (Member # 26) on 07-17-1999, 06:52 PM:
We have a PTR. I wish we had a media cleaner. The only thing the PTR is really great at is removing the dust from film. We always play 3-5 weeks after the break and you all would probably be amazed at the amount of crap that arrives on some of the prints we play.I think PTRs are OK if you clean them religiously, but I'd still rather have the media type. So that's where my vote goes.
Posted by Brian Paymer (Member # 57) on 07-17-1999, 10:09 PM:
MEDIA CLEANING MACHINE. We threw our transfer rollers away because they don't work.
Posted by Tim Spencer (Member # 58) on 07-18-1999, 04:27 AM:
media cleaners. that one was too easy. the ones we have are almost new and were never even sticky at all. the cat hair rollers at k-mart work better. i've cut them into strips and placed onto a ptr. plus they are only a couple of dollars.
Posted by Aaron Mehocic (Member # 15) on 07-23-1999, 01:36 PM:
I've never used a media cleaner, but on thing is for certain . . . PTR's SUCK!!!
Posted by Paul Konen (Member # 41) on 07-26-1999, 01:03 PM:
Media Cleaners
Posted by John Pytlak (Member # 331) on 08-04-1999, 10:55 AM:
PTRs are widely used by the film laboratories to clean the film during printing (less "white" dirt). They are used on most telecines when transferring film to video. They are widely used for special-venue projection like IMAX. They are generally recognized as the most effective, lowest cost, and safest film cleaning method in these applications.Several people in this thread note that the PTRs are removing lots of dirt from the film. So why aren't they working well? Are certain types of dirt harder to remove? Are they not "sticky" enough? Is the mounting equipment poorly designed (e.g., poor guiding, not enough tension, not enough wrap)?
In my experience, dry web media cleaners can be effective, but are much higher risk for scratching the film if an abrasive dirt particle gets caught on the cleaning media. I saw an entire print scratched by one of these cleaners when a projectionist tried to remove abrasive cement dust that had built up on the print during booth reconstruction.
Please help me understand why PTRs aren't meeting your needs, and how they might be improved.
Posted by Brad Miller (Member # 2) on 08-04-1999, 03:01 PM:
In a perfect environment, I can see where PTRs could be of use. However, in typical projection rooms, something a little more powerful than a slightly tacky roller must be implemented. PTRs will fill up with dirt before the trailers are over. (Hence the name Particle Transfer Rollers...transferring the dirt particles from one part of the print to another.) Also the latest ones I saw brand new weren't sticky at all. It was like a piece of rubber. Gordon McLeod has noted to me a brand of PTRs (sorry, not Kodak) he found to work well, but he is using them on IMAX prints which I do not believe is a fair comparison. To me, if they aren't made more stickier, they will never be effective. In my tests the PTR prints were always dirtier than ones left alone. I can explain the testing conditions if you wish, but they were perfectly fair.
As to dry web media cleaners, yes they can scratch...when run "dry". I extend my invitation for you to come witness for yourself the power of FilmGuard in Dallas. Perhaps you would care to take in a screening of Phantom Meance? You won't believe it until you see it
Posted by John Pytlak (Member # 331) on 08-04-1999, 04:13 PM:
I agree that once the surface of the PTR becomes loaded with dirt, it will no longer stick, and the PTR may transfer it from one part of the print to another. Interesting that most of the lab, telecine and IMAX applications, the rollers rarely get so much buildup that this occurs. Is the loading problem restricted to the abrasive projectors?The surface of the PTR is intended to be only slightly sticky. Higher levels of stickiness may cause the film to wrap around and jam, or pluck pieces from the soft polyurethane surface. As you know, PTRs come in a shiny finish (for lower speed applications) and "matte" finish (for higher speeds and accelerations). I test the effectiveness of used PTRs by rolling the PTR across an obviously dusty surface. If it picks up 95% of the particles, the PTR is still effective.
Have you retried PTRs with film treated with FilmGuard? Since lubed film will be much less abraded by the projector, the debris level should be lower and the PTR won't load up as fast. Just wonder if the FilmGuard affects the stickiness of the PTR surface?
------------------
John Pytlak
Posted by Joe Redifer (Member # 3) on 08-04-1999, 04:50 PM:
OK I have to chime in here. Here is the way PTRs work: Put clean ones on, run film, PTRs are dirty by the end of the 2nd reel at best, take PTRs off, wash them, let them dry, repeat each and every show. Ug! Our PTRs have long lost their "sticky". They are not sticky when removed from the print to be cleaned. My estimates indicate that it would take over 6 months to get a dirty print clean using PTRs every show. The only way PTRs are effective is if you use them from day 1, every show, in an immaculately clean booth. But the constant cleaning and drying is not possible in real world booth conditions, especially for every projector. With FilmGuard, you just soak the media pads, thread the film, and don't soak the pads again for another week. Yes, you run the film through the same media pads each show, and the results are phenomenal. It doesn't take much time to rewind the pads each show (less than to wipe out a dirty projector) so the concept of having it on every screen in a large multiplex is sound. We have used PTRs for several months when our theatre first opened, and it is impossible for them to keep up with the amount of shedding coming off of the film. I'm sorry for the single, long, continuous paragraph.
Posted by Gordon McLeod (Member # 33) on 08-04-1999, 05:13 PM:
Personally I NEVER NEVER NEVER was aPTR roller.
Especially The SanLab Blue ones
The best way to clean them is to put a 3' long piece of clear packing tape (it is about 2" wide) sticky side up and tape it to the rewind bench.
Roll the PTR down the tape and just look how much stuff comes off and the roller pores are opened up again
The ones we sell and I have worked with the designer for several years (sorry John) I have found superior namely because the surface is actually machined in a double helix pattern called micromatte.
As the dirt comes off it actually migrates into the micro groves and is trapped there leaveing fresh tacky surface exposed. But they must be cleaned by tape method
The Large format test is really the acid one for Dirt is the single biggest problem. A spec of it is gigantic when it glues itself to a field flattner in the centre of the screen. Also the high film speed 336 feet per minute plus leaves very little time for the dirt to be removed
PTR's are not perfect and I have never said they should be looked at as the sole method of cleaning film but part of a battery of devices that are at our disposal. Every little bit helps
Posted by Gordon McLeod (Member # 33) on 08-04-1999, 05:18 PM:
One thing I forgot to mention
PTR's do not remove static and in fact increase the level of static. Any that are coated to reduce static will clean less efectivly
Posted by Brad Miller (Member # 2) on 08-04-1999, 06:56 PM:
Well, when Terry Westenshow.....whatever it was...I think it is Terry Smith now, sent me a sample of PTRs years ago, I found they didn't work well at all, and in fact made the print extremely dirty (Addams Family I...two prints, identical projectors) as opposed to the one cleaned once with a dry web media cleaner. Granted, I'm sure the PTR technology has improved much since then, but the most recent PTRs I have tested were about a year ago (from FPC) and were less sticky than the originals from that early 1990s test and did not work as well. I do believe they were to "reduce static." Since then a fellow recommended I blow 2 bucks on a "cat hair" roller at the impulse isle at the local Wal-Mart and cut it into strips for placement on the PTR. This actually worked fairly decent. The best part is I could peel it off and toss it when the show was done! How about getting FPC to make roller versions of these where at the end of the show, the top layer can simply be peeled off to reveal another 20 or so layers underneath??? That might sell and would certainly be quicker and easier on the projectionist.Gordon's idea of using packing tape does make sense. I will give it a try as I have many PTRs laying around to test with.
Gordon, can you give us the information as to the brand and supplier of the PTRs you are speaking of? It would be interesting to test. I am always willing to try new products and ideas, even though I doubt it could do any better than FilmGuard. Also, how about testing FilmGuard on an IMAX print?
Posted by Gordon McLeod (Member # 33) on 08-04-1999, 07:45 PM:
The PTR's are made by San Labs Systems in Collingwood Ont
They are distributed by Entertainment Equipment Corp in Buffalo
1 800 448 1656
specifiy that you want the same diametre as the FPC (large) rollers
The problem with the Imax and treated film is any residue that might come off and be left on the field flatner
One has to remeber that the complete image area is held by a vacume against the field flattning lens
Posted by John Pytlak (Member # 331) on 08-05-1999, 08:38 AM:
One risk of a really sticky roller ("cat hair roller" using adhesive tape) is that the film may stick to the roller and wrap-around, causing a jam. The adhesive may also transfer to the film.------------------
John Pytlak
Posted by Brad Miller (Member # 2) on 08-05-1999, 02:22 PM:
All depends on the "cat hair" roller used. It also depends on the back tension of your feed. I haven't done any serious testing with it, just a little bit of playing around and it actually worked.Anyone out there willing to spend some time at their theater after hours with some old trailers for testing this?
Posted by Charles Lubner (Member # 157) on 10-26-1999, 09:28 PM:
Does FilmGuard work with PTR's??
Posted by Joe Redifer (Member # 3) on 10-27-1999, 01:16 AM:
No, FilmGuard does not work with PTRs. In fact, PTRs don't work with anything!I mean really.... who wants to wash and dry a set of PTR rollers EVERY SHOW for every projector you have a cleaner mounted to, even if they were actually effective, which they are most certainly NOT? PTRs are an idiodic and impractical technology. With media cleaners and FilmGuard, you can just rewind the pads after each show (takes less time than wiping out the projector) and you don't have to dry them or take them to a sink.
Posted by Steve Guttag (Member # 268) on 10-29-1999, 07:50 PM:
The only way I have seen PTRs work effectively is to start with a clean print. If one cleans a print with a media cleaner so it is clean...then has 2-3 sets of PTRs for EACH screen...one can run EVERY show through the PTRs and carry his/her bucket-O-PTRs around and swap out used for fresh during thread up. By having 3-sets, you have one running the show, one cleaning and one drying (obviously doing the cleaning/drying while the shows are running).
This way, the film never gets any build up of dirt to clog the rollers.
Still seems like a lot of work to me! I think PTRs have their place but they are anything but a cure all and are sold to people not prepared on how to use them and using merely two rollers (one base side and one emultion) isn't necessarliy wise either...perhaps increasing the number of rollers in the cluster would improve the results.
But frankly, of the booths I've been in (with the exception of those operated by Gary Weyers...currently at the IMAX 3-D in Indianapolis, IN) they only use one set and they are mostly BLACK can covered with "stuff".
Then again, I often don't see the media cleaners with their media threaded right either...that upper one always gets em.
Steve
Posted by Joe Redifer (Member # 3) on 10-30-1999, 02:56 AM:
I do not follow the arrows when I thread my media pads on the media cleaner. Why not? Well, we are using Christie platters, and the cleaners mount UPSIDE DOWN on th platter tree (I actually prefer this rather than right on top of the projector -- just easier to deal with). When it is upside down, the "top" set of pads can over feed onto the film. They all take up the same, but I just have it feed off of the roll from the opposite side to prevent this.
Posted by Brad Miller (Member # 2) on 10-30-1999, 03:42 AM:
Same here. Even the photo on the brochure for FilmGuard has lower supply roll wound "backwards" on the cleaner. It runs better wet or dry.
Posted by David Johnson (Member # 173) on 10-31-1999, 02:08 AM:
We first used PTRs around 10 years ago now and it soon became evidient that they are of no use at all in a less than perfect enviroment. Once they load up with crapp they do just what the name says, transfer it to the rest of the print, so you have a nice clean first half and an even dirtier second half.
David