FP4 edge info very light

[calico]

For those of you who develop your own film......

Wondering if what a lab told me is true.

I wrote to them because I noticed that the edge info for two 120 FP4 rolls (in same job sent to them) looked very different. On one roll, it was very faint, barely legible. I figured that meant that roll was underdeveloped.

Most of the the photos on that roll looked okay, but I always overexpose, which would compensate to some degree for underdevelopment. There were three photos on that roll where I accidentally did not overexpose (or possibly underexposed) which were thin.

The reply from the lab was: “Edge code density varies – I wouldn’t judge over- or under-processing by it. I checked the log book, and we ran your two rolls of FP4 together on the same rack – so, they were processed the same.”

Attached are photos of negs on my light table from the two rolls. The roll with the darker edge code has images with a lot of light colors which may contribute to the negs looking denser compared to the other roll.

The image in my first jpeg, on what I thought was an underdeveloped roll, doesn’t look bad in terms of density. But, as I said, I tend to overexpose. My third jpeg shows one of the images on that roll which is thin, where I must’ve not overexposed or possibly underexposed.

I haven’t checked all the FP4 film I’ve had developed over the years (at various labs), but I’ve checked about 15 rolls, and the edge info is not as light as the roll discussed here.

The edge info on the Tmax 400 sent with these FP4 rolls looks nice and dark, as has edge info on all the Tmax 400 and HP5 rolls they've developed for me in past six months.

If the rolls were truly developed at the same time, as lab said, it does seem an issue with Ilford. Has anyone seen this themselves? I’ve always looked at edge info for clues re developing.

Thanks for your input.

And, yes, I need to start developing my own film : )

P.S. Unfortunately, I don't have a record of lots the two FP4 film rolls came from. I was keeping a record of that for a while, when I was having another problem with FP4 (the mottling from backing paper).

 

[ags2mikon]

I have had this issue with Pan F and it is film that has aged. The latent image, the edge markings, fade away. If you shoot it and wait long enough your image will also fade. Just a thought.

 

[koraks]

I have had this issue with Pan F and it is film that has aged. The latent image, the edge markings, fade away.

That's the first thing that comes to mind, yes. PanF+ is kind of notorious for this, but any film exhibits this phenomenon to an extent. IDK exactly where FP4+ fits on the spectrum. Given how faint those edge markings are, the film must have been pretty old; 15-20 years or so?

Edge code density varies

But generally not within the same film type and the same manufacturing era.

PS: development looks normal to me; perhaps a little on the brisk side. But it's always hard to judge density on photos of negatives. Anyway, I see nothing to worry about here.

 

[calico]

That's the first thing that comes to mind, yes. PanF+ is kind of notorious for this, but any film exhibits this phenomenon to an extent. IDK exactly where FP4+ fits on the spectrum. Given how faint those edge markings are, the film must have been pretty old; 15-20 years or so?


But generally not within the same film type and the same manufacturing era.

PS: development looks normal to me; perhaps a little on the brisk side. But it's always hard to judge density on photos of negatives. Anyway, I see nothing to worry about here.

The film most definitely was not 15-20 years old! If it was expired, it was not more than a few months expired. When I had the problem with the mottling in FP4, I became very careful to not use expired FP4, as Ilford said expired film more likely to have the mottling problem. I have allowed myself to use FP4 when it is maybe three months expired, not more.

Your comment that the fading generally would not happen "within the same film type and the same manufacturing era" would be relevant in my situation. Those two rolls of FP4 were certainly bought close in time to eachother (in past year? or two at most?)

 

[calico]

I have had this issue with Pan F and it is film that has aged. The latent image, the edge markings, fade away. If you shoot it and wait long enough your image will also fade. Just a thought.

Aged how long? This roll would not have been more than a few months from expiration date.

When you say image will fade, too, do you mean if the film is shot but not developed?

 

[koraks]

When you say image will fade, too, do you mean if the film is shot but not developed?

Exactly.

This amount of latent image fading on film just a couple of months past its due date at the longest is not something I've seen before.
Since the images came out OK, I'd not worry about it, but if you're curious, you could contact Ilford/Harman and ask them if they have an explanation. It would help if you could supply them with batch codes on the film boxes - in case you happen to have saved them.

 

[calico]

Miracle of miracles. I just checked my notebook where I note exposures and other info.

I have the info from the FP4 boxes for two rolls in question.

Roll with the light edge info:
05/2024 expiration
FF9331
Roll was shot 6/5/25, so a year and a month from expiration, longer than I had thought. Guess I decided to live dangerously : ) I had been so careful about not using expired FP4 when I was having the mottling problem (or I would only use if expired a few months).

Roll with darker edge info:
09/2025 expiration
FF2624/309/2025
Roll was shot 5/31/25

So the roll with light edge info was older than the other roll, about a year expired.

Interesting that being just a year expired would cause the edge info to get so light.

 

[koraks]

Interesting that being just a year expired would cause the edge info to get so light.

It's the best explanation we have, but I'm also highly surprised, especially since I've shot much, much more expired FP4+ that came out with much stronger edge markings.

 

[MattKing]

Contact Harman.
IIRC, over the years they have made adjustments to the edge printing equipment.
And of course the equipment must be reset every time they edge print another type of film.
So the newer batch may have been set with the edge print settings set normally, while the older batch might have been made with the settings accidentally set for HP5+.

 

[pentaxuser]

And of course the equipment must be reset every time they edge print another type of film.
So the newer batch may have been set with the edge print settings set normally, while the older batch might have been made with the settings accidentally set for HP5+.

So, Matt, does that mean that each setting is made so that it appears as a certain shade of black for a particular development time that the particular film needs in a standard developer, say ID11, so blacks for each film will be roughly the same for all types of film if correctly developed but accidentally using a higher speed film setting for HP5+ on an FP4 using a lower dev time results in the higher film speed edge setting coming out fainter since the FP4 needs much less development time?

I was thinking aloud here when I wrote the above as that was the way my logic seemed to be leading me based on what you said However I have just checked dev time for each film in ID11 stock and in fact HP5+ requires less time so if the HP5+ setting was used for an FP4+film then the extra minute needed for FP4+ applied to the HP5+ setting should have resulted in a darker edge marking not lighter?

I am confused. Really what I should be asking you to do if you will is explain as simply as possible how these settings you refer to are used and how they work

Thanks

pentaxuser

 

[calico]

Along the lines of development times which pentaxuser brought up.....

The lab who developed these two rolls of FP4 uses Ilfotec DD.

(I think DD is the version of DD-X that labs use, because they use replenisher. Correct me if I'm wrong.)

Before I got the reply from the lab where the person claims the two rolls of FP4 were developed together, I checked development times in DD-X for HP5 and FP4 (assume times same for DD as DD-X, didn't see separate tech sheet for DD).

The time for HP5 at 400 ISO is 9 minutes. The time for FP4 at 125 ISO is 10 minutes. I wondered if the FP4 with the light edge info had accidentally been developed with the HP5 rolls they developed that day (ie, underdeveloped).

The person at lab claims the two rolls of FP4 were developed together, though.

BTW, thanks everyone for your input.

 

[calico]

Contact Harman.
IIRC, over the years they have made adjustments to the edge printing equipment.
And of course the equipment must be reset every time they edge print another type of film.
So the newer batch may have been set with the edge print settings set normally, while the older batch might have been made with the settings accidentally set for HP5+.

Interesting.

But given that HP5 is developed less time than FP4, it seems if the edge info was set for HP5 on FP4 film, the edge info would be darker than usual if developed properly in FP4?

There's probably no way of knowing for sure what happened. Just trying to decide if I should keep sending FP4 to this particular lab.

Thanks everyone for your input.

 

[MattKing]

The time for HP5 at 400 ISO is 9 minutes. The time for FP4 at 125 ISO is 10 minutes. I wondered if the FP4 with the light edge info had accidentally been developed with the HP5 rolls they developed that day (ie, underdeveloped)

So, Matt, does that mean that each setting is made so that it appears as a certain shade of black for a particular development time that the particular film needs in a standard developer, say ID11, so blacks for each film will be roughly the same for all types of film if correctly developed but accidentally using a higher speed film setting for HP5+ on an FP4 using a lower dev time results in the higher film speed edge setting coming out fainter since the FP4 needs much less development time?

It is amazing how complex people on Photrio like to make things .
The edge printing is simply an exposure on the film - historically through a changeable mask, but I think it now may be done with electronically controlled light sources that "write" the characters and symbols.
And the machines that do this need to be adjusted to the light sensitivity - the "speed" - of the film receiving the exposure.
So, for example, Delta 100 needs two stops more exposure than Delta 400.
The exposure is set fairly simply - just to whatever level will give the same nice black as you will see in a dense but not over-exposed highlight in any well exposed (at ISO speed) and appropriately developed negative, no matter what the film.
And that will be independent of the developer used!
Because if a properly exposed negative is properly developed in ID-11 at whatever that developer needs for the film, then it will be properly developed in DD-X at whatever that developer requires.
The contrast might differ slightly from developer to developer, and film to film, but edge printing isn't going to require fine tonality!

 

[calico]

It is amazing how complex people on Photrio like to make things .

Agree. That's what makes these discussions so interesting!

The edge printing is simply an exposure on the film - historically through a changeable mask, but I think it now may be done with electronically controlled light sources that "write" the characters and symbols.
And the machines that do this need to be adjusted to the light sensitivity - the "speed" - of the film receiving the exposure.
So, for example, Delta 100 needs two stops more exposure than Delta 400.
The exposure is set fairly simply - just to whatever level will give the same nice black as you will see in a dense but not over-exposed highlight in any well exposed (at ISO speed) and appropriately developed negative, no matter what the film.
And that will be independent of the developer used!
Because if a properly exposed negative is properly developed in ID-11 at whatever that developer needs for the film, then it will be properly developed in DD-X at whatever that developer requires.
The contrast might differ slightly from developer to developer, and film to film, but edge printing isn't going to require fine tonality!

So with that info, my FP4 roll with the light edge info would not have had edge info mistakenly printed with the HP5 edge info setting. If it had, it would be darker than expected, not lighter.

From what everyone has said, either the edge info had faded -- even though the film was just a year + one month expired -- or the film was underdeveloped (which the lab denies).

Thanks.

 

[MattKing]

So with that info, my FP4 roll with the light edge info would not have had edge info mistakenly printed with the HP5 edge info setting. If it had, it would be darker than expected, not lighter.

Nope.
HP5+ is two stops more sensitive to the exposure. So the setting for that would provide two stops less light than the setting for FP4+.
Meaning that if you put the FP4+ in front of the edge printer set to HP5+, your edge printing will end up two stops lighter.
If the same error was made the other way - the edge printer setting was left on the Pan-F setting instead of being switched to the FP4+ setting - the edge printing would be too dark, and probably blown out as well.

And if there is a full range of tones in the image bearing part of the negative, with contrast appropriate to the contrast conditions at the scene, then the film was probably developed properly.

But despite all that, you still really can't count on thoroughly reliable consistency when it comes to edge printing.
Particularly if the film has experienced adverse storage conditions prior to your giving it in-camera exposure, then the years old latent image that is the edge printing may very well deteriorate more than the rest of the film's light sensitive functionality might deteriorate. It is inherently unpredictable, even if it is rarely particularly important.

 

[calico]

Nope.
HP5+ is two stops more sensitive to the exposure. So the setting for that would provide two stops less light than the setting for FP4+.
Meaning that if you put the FP4+ in front of the edge printer set to HP5+, your edge printing will end up two stops lighter.
If the same error was made the other way - the edge printer setting was left on the Pan-F setting instead of being switched to the FP4+ setting - the edge printing would be too dark, and probably blown out as well.

Okay, thanks. I was confused.

And if there is a full range of tones in the image bearing part of the negative, with contrast appropriate to the contrast conditions at the scene, then the film was probably developed properly.

But despite all that, you still really can't count on thoroughly reliable consistency when it comes to edge printing.

Didn't realize there were so many factors to consider when assessing the edge printing.

Particularly if the film has experienced adverse storage conditions prior to your giving it in-camera exposure, then the years old latent image that is the edge printing may very well deteriorate more than the rest of the film's light sensitive functionality might deteriorate. It is inherently unpredictable, even if it is rarely particularly important.

In the case of my roll under discussion, it was only one year old, not years old. But good to keep in mind that very old film might have faded edge info.

Thanks.

 

[MattKing]

Roll with the light edge info:
05/2024 expiration
FF9331

In the case of my roll under discussion, it was only one year old, not years old. But good to keep in mind that very old film might have faded edge info.

A 2024 expiration date means it was probably manufactured in or around 2022 - so the latent image is around three years old.
A lot can happen to an image that is exposed in 2022, and not developed until 2025.
In most cases, the variability of three year old latent images isn't of concern. But if you are trying to draw inferences from the edge print density in the developed film, you probably should do so cautiously.
Particularly when it is film with backing paper.

 

[bedrof]

One week ago I developed few test frames shot the same day on 135 Pan F+ (exp.date 07/2008) and was surprised to see edge markings nice, visible and rather dense for this stock. I've never seen Pan F+ edge markings this clear.

 

[calico]

A 2024 expiration date means it was probably manufactured in or around 2022 - so the latent image is around three years old.
A lot can happen to an image that is exposed in 2022, and not developed until 2025.
In most cases, the variability of three year old latent images isn't of concern. But if you are trying to draw inferences from the edge print density in the developed film, you probably should do so cautiously.
Particularly when it is film with backing paper.

Okay, so a roll of FP4's life is considered to be about two years, per manufacturer. Interesting.

I'm not one to shoot long-expired film, but I've been able to shoot older Tmax 400 with no problems at all. I recently shot a roll that was seven years old, for example. The edge info was clear and dark as can be. Images fine. Exposed as I expose new film.

But I've always had to treat FP4 like a delicate flower. I had the awful mottling issue around 2020 where I communicated extensively with someone at Ilford, sent scans of images, etc. That person told me I was more likely to have the mottling if film expired or if film not kept in proper environment (I am always careful about that). So I didn't use expired film. Then I had the mottling problem even with unexpired film. The mottling issue has been discussed at length here before, don't need to discuss now. I haven't had the problem lately. Now I see the edge info can fade a year after expiration date. As you said, that's not important issue, but it adds to the delicate nature of FP4. I do love FP4 but.....

 

[retina_restoration]

if you are trying to draw inferences from the edge print density in the developed film, you probably should do so cautiously.

You should avoid drawing inferences at all, really. The density of the film ID lettering varies from batch to batch and does not provide any meaningful information to indicate whether or not the film was developed properly.

There’s nothing “delicate” about FP4. I don’t think you can reasonably conclude that the edge ID lettering ”fades after its expiration date” just because you’ve observed variations in the lettering density. There are too many variables to pin the effect on a single factor. It’s irrelevant anyway - as long as your film is not seriously expired and/or been mishandled (stored for months/years in warm conditions) then you need not concern yourself with the lettering density.

The backing paper mottling problem is a separate issue and is extremely unlikely to occur unless the film is expired and/or been mishandled. I’ve exposed hundreds of rolls of Ilford 120 films in the past five years and once I stopped taking chances on long-expired film, I never saw the problem again.

 

[Alex Benjamin]

Following this thread with curiosity, as the same thing happened to me this month. Two FP4+ films with very, very light edge markings. Expiration date October 2023. One was developed in Rodianl 1+75, the other in Barry Thornton two bath developer.

Negatives in both are fine — the one developed in Rodinal was slightly under-exposed, but has a couple of good images on it. The negative developed in BTTB looks good (haven't printed any yet, will do shortly).

The edge markings in the Rodinal-developed negative are uneven — some darker than others, but none as dark as usual. The ones in the BTTB-developed negative are barely visible.

 

[calico]

You should avoid drawing inferences at all, really. The density of the film ID lettering varies from batch to batch and does not provide any meaningful information to indicate whether or not the film was developed properly.

Does the same hold true for color film?

I shot a roll of Provia 100F some years ago that came back really dark. It was a few years expired. Had been shooting from the same expired batch with no problems at all. I use a hand held meter and am very careful about exposures. Have never had problem exposing transparency film. Then this roll came back from a lab where the images were really dark. They had just started to develop E6 film.

When I posted here, showing a sample of the dark roll next to sample from normal-looking roll, someone pointed to the edge info being the wrong color (too red, as I remember) on the dark roll. Said that indicated the film was not developed properly and proved the problem was not with my exposures (which is what I had thought).

But now I'm wondering.....Is it possible for edge numbers on color transparency film to look wrong and images look fine, as in my FP4 roll where the images were fine but edge info faded? Same question for color negative film.

Thanks.

 

[calico]

Following this thread with curiosity, as the same thing happened to me this month. Two FP4+ films with very, very light edge markings. Expiration date October 2023. One was developed in Rodianl 1+75, the other in Barry Thornton two bath developer.

Negatives in both are fine — the one developed in Rodinal was slightly under-exposed, but has a couple of good images on it. The negative developed in BTTB looks good (haven't printed any yet, will do shortly).

The edge markings in the Rodinal-developed negative are uneven — some darker than others, but none as dark as usual. The ones in the BTTB-developed negative are barely visible.

Good to know you had this problem, too.

 

[retina_restoration]

Does the same hold true for color film?

I have no idea. I don't work with color materials.

 

[retina_restoration]

Good to know you had this problem, too.

In reality, it's not "a problem"!

It's like observing that your car's engine is running really rough, and then seeing some scratches on the front bumper and concluding that the scratches on the bumper are somehow related to the engine issue.