B&W Film thickness difference?

I was loading my tanks tonight n had 2 different fiulms, TMY400 and TriX in 120 rolls. After winding on my TMAx, while spooling the TriX I noticed there was a significant difference in film thickness. The TriX seemed so much thinner n flexable than the TMAx.

Well just an observation, I doubt this has anything to do with the preformance of the film but maybe in spooling.

Both films have a film base that is appropriate for their respective make-ups and emulsions. That's it. All is as it should be and you don't have to worry at all about it.

There are two basic types of film stock: Triacetate & Polyester.

Triacetate stock made by Kodak has a nominal base thickness of 142 microns. (0.0056")
Polyester stock made by Kodak has a nominal base thickness of 119 microns. (0.0046")

Polyester is a bit stiffer than acetate but the difference in thickness gives them approximately the same stiffness however, the two types of film both have a distinctive feel to them. Once you get used to handling different types of film you can often tell the difference just by feel.

Secondarily, polyester is a lot stronger than acetate. The stuff is so strong you can literally tow a car with it! If you have a jam-up inside a cine camera or a movie projector there is a good possibility of doing damage to the sprockets and the transport mechanism. Most movies are photographed with acetate based film just for this reason.

The other difference is that polyester based films are less prone to degradation. Acetate films can degrade and start releasing acetic acid vapor which causes the dyes to fade. This is one reason why old, poorly stored, Kodachrome can turn red.

I do not know of any still camera film that is made form polyester. All the film I know of is acetate but that doesn't mean that some companies aren't using it.

If you can tear the film using your fingers, the film is acetate stock, NOT polyester.

Every manufacturer has their own way of doing things and I'm sure that different companies make film with different nominal thickness.

I know that Fuji movie film is different than Kodak movie film. If you pay close attention you can tell the difference just by feel.

I don't see any reason why the same thing wouldn't play out in still camera film.

Basically, you seem to be very observant!

Worker 11811 said:

I do not know of any still camera film that is made form polyester. All the film I know of is acetate but that doesn't mean that some companies aren't using it.

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I think Rollei CN 200 (negative) and CR 200 (reversible) have an acetate support.

Another difference between the two supports is that acetate conducts light more easily, it behaves a bit like a fibre optic so to speak, which means than one has to be extra careful in loading the camera in subdued light to avoid fogging.

One downside I encountered with Rollei's sheet IR film, which I bought from MACO last year, is that although the sheets appear to be the same size as my Fuji Acros sheet film, I have not been able to get them to remain in my dark slides! The Acros sheets are definately thicker, so could the thinness account for my inability to use the 100 sheets I bought (now languishing in my freezer)? I suppose I could try one of Schneider's rare vacuum sheet film holders, but at £600 secondhand, I think that's a step too far!

paul ron said:

I was loading my tanks tonight n had 2 different fiulms, TMY400 and TriX in 120 rolls. After winding on my TMAx, while spooling the TriX I noticed there was a significant difference in film thickness. The TriX seemed so much thinner n flexable than the TMAx.

Well just an observation, I doubt this has anything to do with the preformance of the film but maybe in spooling.

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You got that far before noticing. Many find out when the T-max gets held up between the rollers of their Automat loading Rollei.

I shoot either an RB, ETRS or a Kowa, all well maintained cameras, so no roller problems. The reason I picked up on it, I haven't shot TriX in such a long time, been using TMAx exclusively.

A concern I later thought of with the thickness difference would probably show up more during enlarging, buckling or heat pop. I have a cold light n this won't be an issue for me but people using incandesent lamps n halogen may see this as a problem. Perhaps Kodak had a reason to use thicker base material for their newer TMAx line as a result?

Thanks for the info.

paul ron said:

I shoot either an RB, ETRS or a Kowa, all well maintained cameras, so no roller problems. The reason I picked up on it, I haven't shot TriX in such a long time, been using TMAx exclusively.

A concern I later thought of with the thickness difference would probably show up more during enlarging, buckling or heat pop. I have a cold light n this won't be an issue for me but people using incandesent lamps n halogen may see this as a problem. Perhaps Kodak had a reason to use thicker base material for their newer TMAx line as a result?

Thanks for the info.

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In the 80s I had many instances of the T-max 120 film bulging in the frame during exposure with both my 6000 and TLR Rolleis and YASHICAMAT. I stopped using it for a while, but in the last 10 years or so, it does not seem to be any worse than any other film out there.

Diapositivo said:

I think Rollei CN 200 (negative) and CR 200 (reversible) have an acetate support.

Another difference between the two supports is that acetate conducts light more easily, it behaves a bit like a fibre optic so to speak, which means than one has to be extra careful in loading the camera in subdued light to avoid fogging.

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You have that exactly backwards. The current Rollei films, as well as the current EFKE stock is coated on Polyester. AGFA Says they only have the ability to make Poly base these days. (read their annual Report)

The Poly film will "light pipe" Quite well. I have many 16mm Movie prints and the poly ones pass much more light when viewed on the reel than the acetate ones.

I just developed a 135-36 roll of Efke 100 and it has some light piping near the perfs even though I loaded the camera in teh dark, the film also has a severe curl.

Years ago I work at a place where they used Microfilm, and they had 16mm thin Poly film (215 ft on a 100 ft spool) The techs made a game of trying to break scrap ends one day. Only one guy could do it and then only by using a Karate like move.

Ploy film will stretch however. Acetate will break cleanly.

Poly also cannot be spliced with Film cement. You have to use tape or an ultrasonic splicer.

Kodak calls their Poly ESTAR.

Acetate film shrinks over time, while polyester is way more stable. In the movie film business it's far more common to see polyester as a release print stock than a camera stock, for the above-mentioned reasons about camera jams and their results. But I've got a high speed (up to 10,000fps) 16mm camera that requires precision perf spacing, and I pretty much can't use acetate film in it because of the shrinkage, which occurs with time regardless of how well the film is stored. So I've concentrated on stockpiling ESTAR film for it. Runs smooth as silk... and trust me, the motors in this thing can overpower even polyester, no chance of it getting damaged if jammed!

Duncan

diapositivo said:

...Another difference between the two supports is that acetate conducts light more easily, it behaves a bit like a fibre optic so to speak...

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cmacd123 said:

You have that exactly backwards...

The Poly film will "light pipe" Quite well...

Ploy film will stretch however. Acetate will break cleanly....

Poly also cannot be spliced with Film cement. You have to use tape or an ultrasonic splicer....

Kodak calls their Poly ESTAR.

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See the attached photo: Acetate film on the left. Poly film on the right.

As a matter of fact, this is a quick way to tell film apart. Just hold a roll of it up to the light. If you can see through it, you have poly.

The stuff is so strong you can tow a car with it. I know... I did it just to prove it.
One night, after work, a bunch of us guys got the bright idea to tie some film between two pickup trucks and have a tug-of-war. Yes, the stuff stretches but it takes a heck of a lot to break it.

Duncan, I am guessing you have a Fastex camera? I have only seen one of those once. It was a film eating machine! I would imagine the sprocket holes would tear out before there was much damage to the mechanism.

When Estar film was becoming more popular in the late 1990's, one of the biggest problems was static electricity. The stuff would stick together due to static and cause film jams on the payout platter. There was lots of fun in the booth when that happened. Apparently Kodak had to put some kind of anti-static additive on the film to keep the problem at bay.

Nowadays, 95% of all movie stock is on polyester base. Aside from being more stable, one of the big reasons they say it is used is because it is easier to recycle.

Yes Charles, I wrote acetate but was thinking polyester. I'm glad you corrected me.

Fabrizio

PS I am a fast "blind 10-finger" typer and make such mistakes.

My camera is a Photec, but they're all basically the same idea: massive geartrain locked together at a .3000 perf pitch sending film past a rotating prism. Mine's the 132VDC model, so there is nothing that will stop that motor, not even polyester film. What is interesting is running old acetate film through it as a test - with the shrunken perfs it eventually climbs off of the sprockets and then literally explodes. I open the camera and have a camera full of tiny little film shards to clean up. Photonics even added an "acetate/Estar" switch to soften the acceleration when using acetate, to help limit this problem.

I've been experimenting with older 35mm movie film, including various intermediate an print stocks, and have run into the static problem on the older Estar stuff! I have to spool it realllllllly slowly off the big spool on the rewinds to keep from generating all that lightning. There's one type that I also have the latest version of, and clearly it has the "process-surviving antistatic coating" that Kodak touts, because no matter how fast I spool it off, no static.

Duncan

It was years ago when I saw the camera I was talking about. I don't remember much. I do remember that it ran through a 2,000 ft. roll in under 5 seconds. When it tailed out, it shredded the last 6 inches of film. It was run with the cover off and used junk film just as a demonstration. I remember it sounded like a mini buzz saw.

I am one of those guys who builds his film prints at the rewind bench then spools the pre-built sections of film onto the platter because it allows me to inspect the film as I work. I can do a better job if I have all my tools and supplies at hand and, in the long run, it saves time.
As such, I usually end up rewinding a 6,000 ft. reel full of film at the bench, using the motorized rewinder.

If you want to have some fun, lightly hold your hand on the edges of the film as it speeds by. Your body will build up a nice static charge. It's sort of like a spin-off of a Van de Graff generator, if you think about it.
One time, I had a xenon lamp on the table and, when I felt like I had a good charge, I touched the metal base of the lamp and discharged myself. It flashed for a split second. It was really funky!

Even with the antistatic coating, I still have the habit of keeping my leg in contact with the grounded, metal chassis of the rewinder control box to prevent static build up before it starts. It's funny at first but, after getting shocked 100 times in one day it gets annoying and, sometimes, downright painful!

Is Rollei Pan 25 made out of polyester? I tried to rip a negative apart with my hands a couple of days ago, had no chance!

Grainy said:

Is Rollei Pan 25 made out of polyester?

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35mm and rollfilm polyester, 100µm, crystal clear

acording to the data sheet at http://www.freestylephoto.biz/pdf/Rollei_Pan_25.pdf

One point to add is the different life expectancy between acetate and polyester film base.

The current standard for residual thiosulfate, ISO 18901:2002, recognizes the different life expectancies of roll and sheet film, most of which are coated on acetate and polyester substrates, respectively. According to the Image Permanence Institute (IPI), an acetate film base has a life expectancy of only 50-100 years, but a polyester base has a predicted life expectancy of over 500 years. Consequently, the LE500 value is only applicable for polyester-base sheet films, since acetate-base roll films don’t last for 500 years.

Who has a list of current polyester-base roll films?