Film-Tech Forum ARCHIVE: Particle transfer roller effectiveness

This is topic Particle transfer roller effectiveness in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Adam Ladds (Member # 6757) on 11-04-2012, 09:55 AM:

Hi all.

We run an entirely second-run cinema in the heart of London, UK. This obviously means we get prints which have been mis-handled, poorly broken down etc.

We sometimes notice that some of the dirt and detritus on the film is things like bits of chinagraph pencil, the odd splicing tape "square" etc. Would it be worth investing in a set of particle transfer rollers to clean up our film or aren't they particularly effective at that? (I understand that it won't do anything for the occasional scratched print we encounter.)

Thanks!

Posted by Jake Spell (Member # 5294) on 11-04-2012, 10:53 AM:

Theres a review here on just how bad PTR rollers suck. Iv had great luck with film gaurd cleaning, lubricating and repairing minor scratches.

Posted by Christian Appelt (Member # 1067) on 11-04-2012, 11:27 AM:

A Kelmar-type cleaner with FilmGuard will help enormously. You also could get a Kinoton/Retheto wet cleaner, it can be used with any suitable film cleaner or simple isopropane alcohol.

The unit mounts on the projector or between platter and projector. Don't know whether Kinoton still sells it, but Sondor has a used one on their sales list for 50 swiss francs (about 34 GBP).

Sondor.ch

I use the Kinoton/Retheto cleaner with microfibre plush which is soft enough to take up small particles. Very little cleaning fluid is needed because of the special construction.

If you run the same prints often, go with the Kelmar/FilmGuard solution. If you have to show different prints once or twice only, I'd recommend the Kinoton cleaner because FG needs one or two runs to work best.

PTRs won't help in projection because there is more dirt on a used 35mm print than they can take, the place for PTRs is in printing, scanning and telecine operation to remove the last dust particles which may have escaped the previous negative cleaning.

Posted by Randy Stankey (Member # 64) on 11-04-2012, 01:34 PM:

We use PTRs on our 70mm at the TREC center.
In this case, they are needed to keep the film clean BUT the film is pretty clean to start. If the film was dirty when we got it, the PTRs would be swamped with dust and dirt. They would stop working part way through the film.

PTRs are for maintaining prints that are already in good condition but don't work on film that is dirty or damaged.

As others have said, a Kelmar (or other make) of film cleaner combined with FilmGuard is the right tool for this job.

Posted by Bajsic Bojan (Member # 4928) on 11-04-2012, 02:32 PM:

for 35mm use i only found it "convenient" in situations when you have:
- changeover booth
and
- 4 sets of rollers
and
- you clean/rinse them every reel
and
- a decent enough projectionist to do the above.

Otherwise they do more harm than good.

Posted by Mark Hajducki (Member # 1732) on 11-04-2012, 03:24 PM:

PTRs quickly become saturated and then just move the dirt about. I found that using PTRs (with a long play system) resulted in worse prints than using nothing.

Posted by Louis Bornwasser (Member # 3063) on 11-04-2012, 04:48 PM:

Pretend you have:

1. 6 cats, longhair

2. 1 used lint roller.

Hopeless, right?

Posted by Monte L Fullmer (Member # 2797) on 11-04-2012, 06:21 PM:

PTR = transfers particles from the front of the roll to the rear of the roll.

Kelmars units are tons better.

Posted by Cameron Glendinning (Member # 3516) on 11-04-2012, 06:23 PM:

Ive used PTR's and I have used Film Guard, Film Guard is much better for use in rep cinemas as it can fill in light base scratches and also improves the picture overall including colour. We used it on a beat up 60's print of "Thunderbirds Are Go" many years ago and after a couple of runs it was looking near new. Brad Miller's invention is brilliant!

Posted by Joe Redifer (Member # 3) on 11-04-2012, 09:08 PM:

quote: Louis Bornwasser
Pretend you have:

1. 6 cats, longhair

2. 1 used lint roller.

Hopeless, right?

That really says it all. I wish I had thought of this when I wrote that review a billion years ago.

Posted by John Wilson (Member # 269) on 11-05-2012, 05:51 AM:

Lol @ Louis. Brilliant! [thumbsup]

Save your money if you intend to buy PTR's. [puke]

Posted by Adam Ladds (Member # 6757) on 11-05-2012, 06:04 AM:

Thanks for the insight! We usually run films for a couple of showings at most (or in the case of special events, just once in addition to previewing) so I'll have a look at a Kinoton/Retheto wet cleaner; especially since it's got a lower upfront cost than many of the other options!

Posted by John Wilson (Member # 269) on 11-05-2012, 06:24 AM:

Add Filmguard and all your worries are over.

Posted by Frank Angel (Member # 248) on 11-05-2012, 09:47 AM:

Particle Transfer Rollers only do what the name says. It transfers particles. It won't take away the real dirt that is grease or adhesive based, i.e., most of what you see on the screen marring the picture. PTRs are useless against things like finger prints, adhesive residue or grease pencil marks. For that you need a solvent. So they only remove particles that are only adhering to the print by static electricity; if the particles are held there by their own adhesive properties of chemical composition, like finger prints or china pencil or white-out, they will just laugh at being tickled by a passing PTR roller.

The PTR is also true to its "transferring" function;" it almost always transfers the particles to some other part of the print once the roller gets dirty which, if you are lucky won't be before the end of the first reel.

But for all the faults of the PTR, it's concept was laudable and it does work if you were running 2000ft reels of from-the-lab new prints in changeover and have the time and inclination to wash the PTRs after every reel or if you had a few dozen of them at the ready that you could swap out after each reel and then wash at the end of the night. That said, any discussion of PTRs does remind me of one of this boards most knowledgeable and generous and kind member/contributors, the late John Film-Done-Right Pytlak, who was instrumental in their invention an availablility -- an early attempt to address the problem of dirty prints which was at the time escalating exponentially in exhibition and to which he called to attention of the whole industry with this effort.

We remember him here fondly; a tip of the hat to John.

Posted by Manny Knowles (Member # 1171) on 11-06-2012, 01:35 PM:

I use them...sometimes.

I don't bother using PTR's on "hopeless" prints -- because I agree with everything that was said about that. (Especially Frank Angel's comments.)

Also, PTR's work best with a dry print. So if you have a print that still has a coating of liquid cleaner (like FilmGuard) on it, you're just going to end up with slippery PTR's if you use them on that print.

However -- IF you are running a clean, dry print -- IF you are projecting via changeovers -- and IF you will clean or swap out the used PTR's after each and every reel -- they can aid in keeping a clean, dry print looking clean -- basically, they will prevent new dust from accumulating on the print.

The "nutshell" version is -- In a repertory situation, most prints won't benefit from PTR's.

While FilmGuard is a fine product, you need to know that certain archives will not permit you to apply ANY liquid cleaner to their prints. So it's important to familiarize yourself with the rules/expectation of each particular lender.

I also don't use PTR's on old, brittle prints, because it's possible to separate the emulsion layer completely from the base. They make "less sticky" (matte) rollers, but I still don't use those on old prints. The benefit is insignificant, compared to the risk.

Posted by Leo Enticknap (Member # 534) on 11-06-2012, 02:06 PM:

Agreed completely with Manny. I used to find that if you had a brand new print and were going to run it on a platter four times a day, then PTRs in the film path definitely helped to keep it clean. But if you've got a knackered old print, then using a PTR on it is like using a toothbrush to sweep a yard - it's not going to help you very much.

Posted by Brent Francis (Member # 5008) on 11-07-2012, 03:44 PM:

Thank you for confirming.

Posted by Mark Hajducki (Member # 1732) on 11-08-2012, 09:01 AM:

quote: Leo Enticknap
if you had a brand new print and were going to run it on a platter four times a day, then PTRs in the film path definitely helped to keep it clean

Although if you had film adverts you would need to swap the PTRs before the start of the feature to remove the dirt supplied by the advertising company (who swapped adverts between cinemas).

Posted by Manny Knowles (Member # 1171) on 11-12-2012, 02:11 PM:

Or you could clean the ads before placing them...

Posted by Leo Enticknap (Member # 534) on 11-20-2012, 06:10 AM:

quote: Mark Hajducki
Although if you had film adverts you would need to swap the PTRs before the start of the feature to remove the dirt supplied by the advertising company (who swapped adverts between cinemas).

Good point. At the only place I worked that had PTRs, we typically ran two films, one at 2pm and 6pm and the other 4 and 8. Therefore, we ran the ads and trailers on a separate 2,000 foot reel and then the feature from the platter. The ads wouldn't go through the PTRs, but the feature would.

Manny - not sure if this is still the case (they're probably DCP only now), but when I was working in cinemas that showed adverts, the supplier did not send us complete reels that we could just swap out. They sent a box full of little 50-150foot rolls of individual ads (not even on cores), with instructions to remove the outgoing ads from our existing reels and return them, and splice the new ones in. It was a mind-numbingly boring job I hated it. Obviously, with dozens of cinemas editing these ads in and out of their reels all the time, the prints soon got totally knackered, especially if, like us, you were a second run cinema at the end of the chain. You would have needed an ultrasonic cleaner to make those prints even remotely presentable, and even then it probably wouldn't have done much good. I agree completely with Mark - if you'd have run an ads+feature programme straight from a platter through PTRs, then the PTRs would have exhausted their usefulness by the time you got half way through the ads.