Quality control experiences with 120 B&W negative films on PET base?

Oren Grad

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A number of vendors offer B&W negative films in 120 rolls coated on PET base rather than the cellulose acetate more commonly used for 35 and 120. I can get a decent sense of the sensitometric properties of these films by reading data sheets and posted reviews. What's harder to get a handle on is the risk of encountering production defects. So I'm interested here in any observations about quality control from people who have used these films - frequency and character of any sample defects you've encountered, and on the other hand whether you've had especially good luck with particular films.

We obviously won't have a statistically representative sample here, and reports may well be biased toward those who have had a problem. But I'm interested to hear about your experiences even on an anecdotal basis.

I should add a couple of things: I'm aware that Adox is working on bringing 120 film back to market, but also that it's likely to be a while yet. Also, I'm well aware of the various issues associated with backing paper and adverse and/or extended storage of Kodak and Ilford 120 films - no need to belabor those.

Thanks for any observations that anyone can share.
 

AgX

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What "production defects"? Films with PET base are being made by several manufacturers all over the world since many decades. For most demanding applications.
 
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Oren Grad

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120 B&W negative films on PET base that are currently marketed to consumers come either directly from a manufacturer that has an established reputation for QC issues (Foma) or from marketers who private-label films coated and finished by others (Freestyle/Arista, Holga, Bergger, Rollei, JCH, perhaps others). The long history of successful production of such films shows that in principle it can be done to a high standard but does not tell us what we can expect in practice from the current consumer products I'm asking about.
 

grat

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Aren't nearly all of Kodak's films now on Estar? That's PET.

I know the new Gold 200 is, I'm pretty sure Portra 400 is, and tr-x 320 (sheet film) is.

There was a comment on here last year about Portra 800 and Colorplus being moved to PET as well, due to problems with acetate supply.
 

Besk

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That is really interesting to hear. PET is far more archival. I would love for Kodak to go to PET base for its black and white roll films.
 
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Oren Grad

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Virtually all sheet films have been on polyester for a long time. However, so far as I know, none of Kodak's B&W negative films offered in 120 rolls has been moved to a polyester base, nor any of Ilford's. If and when that changes, or if it has already happened and I've missed it, I certainly want to know about it.
 

AgX

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The type 120 films with PET base that come to my mind are converted from current Agfa stock.

From that other manufacturer's quality issues you refer to I do not see any related to the base.
 

AgX

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One of the differences between TAC and PET is their tenacity. But so far no problem with PET has been reported. (Keep in mind that we got issues with TAC rollfims in some cameras due to their film path.)

We could discuss thicknesses too.
 
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Oren Grad

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I'm not concerned with whether problems are caused by the base, only whether the currently-marketed films that use that base have problems, whether related to base, emulsion, backing paper, or anything else. My interest here is practical, not academic - I'm deciding whether I want to invest the effort in trying any of these films.
 

cmacd123

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many 120 films are on Polyester base. some have been for years. 120 is transported and loaded with a protective backing paper, so the stronger base jamming in the sprockets, or the inevitable Light piping risk asocitaed with Polyester is less of a worry with 120.

I wonder if the folks who find "defects" with Foma are just unaware that it requires more care in handling than other films, being not as strongly hardened.
.
 

MattKing

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The Kodak version is Estar, which they have been making and using for a very long time. That is the base dealt with here: As mentioned in this thread: https://www.photrio.com/forum/threa...-manufacturing-from-smarter-every-day.190694/
Changing a film from acetate to Polyester requires some re-design, and there are potential issues with light piping, but those are issues that have been dealt with many times over many years.
Just don't try to tear the Estar film with your teeth!
 

AgX

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The problem is that Oren raises a question out of the blue without having any hints that may cause the question.
 

koraks

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AgX said:
The problem is that Oren raises a question out of the blue without having any hints that may cause the question.
Click to expand...
He seems to misinterpret the persistent problems with one particular emulsion (Foma 200) as somehow being indicative of risks associated with a certain base material. Don't ask me how the logic goes...

I've never seen a relationship between film manufacturing defects (quite rare to begin with) and film base material.
 

AgX

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Well, basically there is: adhesion of emulsion to base.
But as you say, we have no reports here of such specifically related to PET based films.
 

AgX

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Where Oren may have a point is that in the past PET-based type 120 films were all converted to 120 by an entity not being the film manufacturer and which may have lower quality standards.

In the long past Maco stated that they had the films converted by two different firms, which also resulted in different retail prices. You would have to search for old reports on the respective conversions. Their meaningfulness for today would be limited anyway.
 
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koraks

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AgX said:
Well, basically there is: adhesion of emulsion to base.
Click to expand...
Of course, but no horror stories from recent decades are known to me about emulsion peeling off of film under normal processing conditions. This is also pretty much the very first thing that even a DIY film maker would get right (let alone a professional outfit) because it's so fundamental.

IDK, anyway, I wouldn't hesitate to invest the time, effort and money in trying out film whether it happens to be on a polyester base or not.
 

AgX

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Adhesion is not that banal as you make it look like. One film manufacturer even hinted at respective possible issues for the user we never discussed here.
 

koraks

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I don't make it look banal. I'm pointing out it's the first hurdle that anyone will have to face and no manufacturer of film will release any product unless they have very thoroughly investigated it. Hence it's so rare to see adhesion problems "in the wild" despite the challenging nature of the issue.
You're confusing "fundamental" with "banal". They are NOT synonymous.
 
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Oren Grad

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koraks said:
He seems to misinterpret the persistent problems with one particular emulsion (Foma 200) as somehow being indicative of risks associated with a certain base material. Don't ask me how the logic goes...
Click to expand...

No, that's not what I meant at all. I am not attributing problems to the base per se - if that had been my concern I would have said so in my original post. See my post #9 above.
 

AgX

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I am not confusing these two terms, instead I tried to make you aware that you are just limiting your perspective in seeing possible issues. Issues outside the scope of this thread but nonetheless considered by the industry.
 

MattKing

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I've added a question mark at the end of the thread title.
 

grat

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I've used Arista EDU 400 and Rollei Infrared 200, both in sheet form.

The only film that meets the criteria I've used is Bergger Pancro 400. If it truly has an anti-curl layer, I'd hate to see what it's like without it.

Most of my shots came out reasonably well, but with noticeable mottling in the shadows in one or two frames. Having experimented with a number of films, Pancro 400 is so far, my kryptonite. I know there's potential I'm not reaching with the film, but I'm not sure what's stopping me.

And if someone can explain this abomination, I'd love to hear it:



So first, I mean the photo, not the cat. He defies explanation.

The photo is my first attempt at manual flash photography, and the negative is a bit thin-- perhaps 1, maybe 2 stops underexposed. It's also mostly unedited (slight anti-Epson sharpening).
 

Lachlan Young

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Oren Grad said:
What's harder to get a handle on is the risk of encountering production defects.
Click to expand...

If properly engineered for the intended end-use, there should be none. Kodak made numerous specialist aerial film products for extremely sensitive national security applications on incredibly thin Estar base materials - and given the nature of the missions they were used on, even small defects would present issues.

The problems arise when cross-conversion of products intended for one market into another (some of Maco's conversions of Agfa aerial materials) are not done well (cheaply/ or on out of adjustment machinery) or where the manufacturer feels pressured to produce as cheaply as possible (Foma) & seem unable to make the necessary investment to resolve an issue of this nature. If people were willing to pay Ilford money for Fomapan, I understand the Fomapan 200 issues would largely resolve themselves. Given the choice, I think that the manufacturers would prefer to coat on Estar, were it not for the risk of a film jam causing potential camera destruction - and it makes considerable sense to move to Estar bases for 120, as and when coating packages come up for review etc (or intro/ re-introduction to a new format).
 
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