T-Max 400 has boomerang curve

Shawn Dougherty · Apr 16, 2013

Michael R 1974 said:
On a personal note this curve wouldn't bother me as a user. From a printing perspective it is essentially a straight line with some extra contrast in the very high highlight densities. Actually - this is not all that different from Acros.

Thanks, Michael.

Photo Engineer · Apr 16, 2013

Ok, what I have seen here are good and bad curves. Now, what is it due to? If you have good and bad from one batch then it is processing but if you see good from one batch all the time and bad from others all the time, then it is probably a bad blend. Now bad? Well, what do the photos look like? If they are ok, then there is no problem.

You see, there is a curve tolerance spec, and if the film is within that (D76) then it is released. If not, it is destroyed as scrap. I cannot tell, without extensive tests, if these batches are good or bad, but the curves look like a bad blend due to the kink in the center. And this is the perennial problem encountered when you use blends of emulsions. If you miss, you have a kinked curve and if the kink is too bad, then the batch is bad.

I would not worry if the photos taken look good.

PE

Shawn Dougherty · Apr 16, 2013

Michael R 1974 said:
Shawn, here's a cleaner version showing only one curve of approximately 'normal' contrast from the series above.

To make it more relatable I changed the labeling on the X-axis and added "Zone" indicators.

What you have is a very straight curve (constant contrast) up to around Zone VIII. After that contrast increases and remains relatively straight until around Zone XII with a gradual shouldering (reduction in contrast) thereafter.

In the real world this means you have a pretty straight line until you get into the high highlights where you have a lot of local contrast. If you have those densities in the negative, it would take some extra burning in to bring them into the print. Not really a big deal. The extra contrast in the extreme highlights would tend to offset the compression in the toe of the paper. Basically all I'm saying is you'd have to do more burning in, but it would be slightly easier to retain local contrast (detail) in the highlights if you're burning them down at lower grades.

Fuji Acros has a similar curve, with a less gradual shoulder.

This type of curve could be a better candidate for compensating and other extreme contraction procedures because since the film inherently has high highlight contrast, it can stand more contraction without completely flattening the highlights.

Note different people might like or dislike a given curve shape so to some extent this is all subjective.

It is also important to note if you're regularly using TMY-2 you've probably subconciously adapted your printing to the curve anyway, so nothing to worry about - unless it is not the normal curve for the film.

Excellent. Thank you for laying that out there, Michael. I really appreciate it. This makes total sense. I will often times make a couple of test sheets with my highlights burned in at different grades and pick what I like the best, so I would definitely be compensating for any required change due to increased contrast in the highlights.

David Allen · Apr 16, 2013

I may be a philistine here but, do these test curves matter??

Surely the only thing that matters is whether you can get good results with any given film.

I have seen many technical tests of Delta 400 that demonstrate many strange and curious unexplainable things - all I can say is that with my exposure/development regime I ALWAYS get the results that I want using Delta 400 with an EI of 200 in Barry Thornton's Two-Bath developer.

Best,

David
www,dsallen.de

Andrew O'Neill · Apr 16, 2013

I'll have to check my curves for TMY-2. From what I can remember, the curve shape can change according to developer used and dilution. TMY-2 is one of the most flexible films in this regard.

albada · Apr 17, 2013

Michael R 1974 said:
Hi David - no you're not a Philistine at all. What is missing is the context. This thread was started by Mark in relation to the detailed testing he was doing with his developer (see his recent posting in the articles section regarding "Mocon").

Michael: Thanks for the reminder about this. I described the problem to Kodak, and a week later they sent me an email asking me to call them. That was a couple of weeks ago, and frankly, I'd forgotten about it. I'll call them tomorrow or Thursday and post an update.

PE: I appreciate the explanation that curves like this occur with blending problems. One thing that surprises me is that Michael's latest curves are from batch 0169, and my batch was 0167. Two batches later and it hasn't been corrected? Or is a master roll divided into multiple batches, so that several batch-numbers would have the same issue? Anyway, Kodak is hurting financially, so I wonder if a borderline run was marketed to avoid the cost of a re-run.

Curves tell a lot. With a couple of other films, I could detect a slight wiggle in the middle. It was certainly not an issue, but told me that something was happening in the film: The curve was transitioning between emulsions.

Mark Overton

Rudeofus · Apr 17, 2013

albada said:
Curves tell a lot. With a couple of other films, I could detect a slight wiggle in the middle. It was certainly not an issue, but told me that something was happening in the film: The curve was transitioning between emulsions.

The big question remains whether the batch is within tolerance or not. A 25 kg sack of rice doesn't always contain 25000 grams of rice. Note that your method of emulsion evaluation is more precise than what most folks here (including myself) ever did, at least privately.

I look forward to hearing what Kodak tells you about this issue.

Photo Engineer · Apr 17, 2013

You must remember that the number on the film does not relate to the emulsion used. Two different coating numbers may have used the same emulsion but may have been coated on a different date, or they may be the same coating date but from different master rolls. IDK. I don't keep track of that stuff any more.

PE

albada · Apr 18, 2013

Here's an update about Kodak's customer-support for this issue. For review, they sent me an email telling me to call a phone-number, which I just did.

The phone-number they gave me was general tech-support, probably in India, and they knew nothing about film. They gave me another number to call.

That number was tech-support in the USA (no accent anyway), but they also knew nothing about film. But the woman was helpful: she dug into some database and located a planner in the film division, and asked him to contact me by email. If he responds, that at least gets me into the film-division.

I'm surprised that my original report was not routed to their film-division. It sure is hard to contact anybody there.
Ron, do you know any employees there who would know where problem-reports should be sent?

Mark Overton

Photo Engineer · Apr 18, 2013

I'll try to get something for you, but offhand all of my numbers are old.

Did you try the 800# on the film box? They used to have one there.

PE

albada · Apr 19, 2013

Photo Engineer said:
I'll try to get something for you, but offhand all of my numbers are old.
Did you try the 800# on the film box? They used to have one there.
PE

I just checked; there are only a couple of Internet URLs on the box now, and no phone number.
Today, they emailed me about my complaint that this issue has not been resolved. Quote:

"We are sorry to inform you that we do not support Films please contact toll free: 1.800.698.0916 ext 16 or 800-847-8755 Ext 11".

Mark

Photo Engineer · Apr 19, 2013

Then call those numbers. That is about all I can say.

PE

albada · Apr 19, 2013

Photo Engineer said:
Then call those numbers. That is about all I can say.
PE

I called one number yesterday and the other today. Both cases led to customer support who knew nothing and tried to transfer me elsewhere. But today, it resulted in being put on hold and finally hearing this message: "We are presently too busy; please call us back at another time."

I think I'll try entering a new problem-report through their web-site, but I'll start it with "Film issue: ...". Hopefully that cause somebody to route it to their film-division. Surely Kodak has somebody in the film-division who can receive trouble-reports.

Mark Overton

L Gebhardt · Apr 19, 2013

You could also check with one of the vendors like Canham cameras; they may have a contact person who can help.

L Gebhardt · Apr 19, 2013

Also, have you checked another film size such as 120 or sheet film? Those at least need to be coated separately.

Rafal Lukawiecki · Apr 22, 2013

Mark, if you call 1-800-242-2424 (I got this number from John Sexton) and dial extension 19, then select no options and just wait for a person, you will get to the remnants of Kodak Pro support. I have just called to check, and I spoke to a nice lady who confirmed that they can offer TMax-related support, but they are very limited with the information they have, as they focus on equipment nowadays. However, she said she could pass your query on to someone else. I had an impression that this number used to go to a more dedicated team focused on Professional Imaging Solutions, but it is now being routed to a different group.

She was kind to give me her email address, too, I will PM you that in a moment.

Good luck, and thanks for all of your work.

albada · Apr 23, 2013

Rafal Lukawiecki said:
Mark, if you call 1-800-242-2424 (I got this number from John Sexton) and dial extension 19, then select no options and just wait for a person, you will get to the remnants of Kodak Pro support.

Rafal, thanks for the number, and for the PM with the contact. It's a pity that it's so difficult to get a trouble-report into Kodak's film-division. It appears that that division is isolated from its customers, which is a dangerous way for any company to operate. It only takes one hour per day for an employee to monitor and respond to a couple of Internet forums, which is a negligible expense even for a company fighting off bankruptcy.

@L Gethardt: Testing 120 film is a good idea. I've done all my work with 35mm, but after reading your suggestion, I realized that I have everything needed for testing 120 as well -- except the film. I think I'll add some to my next order.

Mark Overton

GraemeMitchell · May 13, 2013

I was wondering if anything ever developed further on this strange curve, the inquiry to Kodak, or further (non 35mm) tests?

albada · May 14, 2013

GraemeMitchell said:
I was wondering if anything ever developed further on this strange curve, the inquiry to Kodak, or further (non 35mm) tests?

A test-engineer at Kodak contacted me by email. He read this thread, and Kodak decided to run some tests. They ran samples from several batches of film which they had stored. These batches were dated before, during, and after the failing batches reported here. All turned out fine! He even sent me the graphs. All were fine.

I wanted to ask him to run tests of film purchased on the open market. Both Michael R and I saw this problem, and Kodak didn't, and that suggests to me that this issue is related to storage-conditions. But the last email sounded like Kodak had decided that everything was fine, and wasn't going to investigate this more, and that's how the story ended.

Mark Overton

Photo Engineer · May 14, 2013

Heroic work for us Mark.

PE

Photo Engineer · May 18, 2013

Michael, they do post curves on-line, but geez, I've got a few here that I've never scanned in.

Each division plotted them differently though, so it might surprise you to compare mine with the on-line curves to the ones sent to Mark.

PE

albada · May 21, 2013

Michael,

The best curve didn't have numbers on the X-axis, which would have been great for calibrating log-E.
The other was a group of six or so curves, all superimposed, forming a band in which you could see variations from each other. It showed that Kodak's manufacturing was staying within reasonably tight tolerances, but that's still not what we want for comparing with our own work.
Bottom line: I have no curves to post that would help us with our own measurements. But I can post what I got if you're still interested.

Mark

Shawn Dougherty · May 21, 2013

Michael R 1974 said:
Hi Mark - if it isn't too much trouble to post them I'd still be curious to see them.

Michael

I would also be curious to see them, Mark. Thank you!
Shawn

albada · May 22, 2013

That's two requests, and others are probably interested too, so here goes.
The curves below show the lower- and upper-contrasts for all recent batches of TMY2. It's clear that nothing has changed in the last few months:

And here are the curves of recent batches. They all fall within a reasonably close band, so once again, no problem:

As a result of my query, Kodak pulled some sample films from storage, exposed and developed them, and plotted the above curves. I was hoping they would include samples purchased from the open market, but I'm guessing the curves above convinced them that everything is fine.

Mark

Shawn Dougherty · May 22, 2013

Thanks for posting these, Mark!

T-Max 400 has boomerang curve

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