FP4 edge info very light

koraks · Tuesday at 10:00 AM

calico said:
Does the same hold true for color film?

In general, I couldn't say, but specifically concerning Kodak's KEYKODEs I know that no inferences should be made about the hue or density of these edge printings. I have a feeling they're quite consistent - but it's really just that, a feeling. There's some discussion on it here: https://www.photrio.com/forum/threa...-edge-printing-on-kodak-vision3-films.202974/ But most of that is about the meaning of the numbers, not so much the density.

calico said:
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).

That might have been me; at least I vaguely recall something along these lines. I've shot quite a bit of Fuji slide film in the past and the edge markings on those films were all a golden yellow. I never specifically went looking for how consistent they were, but a more reddish orange is something I don't associate with those edge markings.

Prest_400 · Tuesday at 10:33 AM

Interesting, during the winter I noted that the edge markings of Delta 3200 were of a different density between two rolls I had and the same developer (XT-3) used and the negative appeared a bit thin. I chucked the last ml of the developer thinking it had lost activity but then the negatives printed very well. Could very well rather unrelated and I had not been that much of a consistent user of the film as to assess this.

Matt's setting change could be a manufacturing culprit, though would think Harman are very good at QC. Recall sometime reading that someone got mismarked Delta 400/HP5, if that would be a circumstance. Not finding it so cannot cite, so take it as anecdotical.

With the topic discussion I was curious if there is any standard in the exposure of the edge markings aka DMax. Found this thread from 2003 in which there are comments that no, it is just a general guideline.

https://www.photo.net/forums/topic/53820-the-markings-along-the-edges-of-the-film/

As of color, I have noted some scans of people where the colour shade of the edge markings very, specifically for Color Negative which might show just inversion adjustments. IIRC these are golden yellow in both Kodak and Fuji (E6, C41) where I would be considering a properly processed E6 as the reference for the precise color.

koraks said:
That might have been me; at least I vaguely recall something along these lines. I've shot quite a bit of Fuji slide film in the past and the edge markings on those films were all a golden yellow. I never specifically went looking for how consistent they were, but a more reddish orange is something I don't associate with those edge markings.

OP: I am a new P645n user and the data imprinting feature is cool! Was thinking to comment about it, but really it would not make so much of a difference but you would have seen how consistent the exposure data would be across the two rolls.

calico · Tuesday at 11:49 AM

koraks said:
That might have been me; at least I vaguely recall something along these lines. I've shot quite a bit of Fuji slide film in the past and the edge markings on those films were all a golden yellow. I never specifically went looking for how consistent they were, but a more reddish orange is something I don't associate with those edge markings.

Yes, maybe it was you. And the edge info on the presumably mis-developed roll was reddish orange instead of the usual golden yellow.

calico · Tuesday at 12:00 PM

Prest_400 said:
OP: I am a new P645n user and the data imprinting feature is cool! Was thinking to comment about it, but really it would not make so much of a difference but you would have seen how consistent the exposure data would be across the two rolls.

Good point!

Interestingly, the roll of FP4 with the light edge info was shot on my new-to-me Pentax 645NII. It was one of the rolls I shot to test the camera. But I had turned off the function where the camera records the aperture, etc. on the film.

Darn. That would've been interesting -- to compare the camera's edge info with Ilford's. If the film was not underdeveloped, the camera's edge info would've been dark as it should be.

The other FP4 roll, the unexpired one, developed at same time as above roll, was shot on Contax 645. Both the Ilford edge info and the camera's edge info were dark as should be.

I'll have to turn that function on for the Pentax 645NII so I can use as reference, compare to manufacturer's info, in future.

Thanks.

koraks · Tuesday at 12:04 PM

You already know that the film wasn't underdeveloped. You can tell by the negatives.

retina_restoration · Tuesday at 12:07 PM

koraks said:
You already know that the film wasn't underdeveloped. You can tell by the negatives.

Yep. There's no doubt about that, which is why looking at the edge lettering is a useless diagnostic for development (in this instance)

calico · Tuesday at 12:22 PM

koraks said:
You already know that the film wasn't underdeveloped. You can tell by the negatives.

Yes, the images basically look fine. But I always overexpose a little (100 ISO instead of 125) which would compensate for some underdevelopment, and the images looked a bit less dense than those on the other FP4 roll with the dark edge info. So development, in my mind, seemed slightly ambiguous.

pentaxuser · Tuesday at 12:25 PM

MattKing said:
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!

Well Matt some if us are simple souls who need help in understanding how different edge setting for different films work I certainly need help. So is it possible to explain to me exactly how a longer dev time for FP4 which has an HP5 edge setting imprinted on it by mistake results in a fainter edge marking when you'd think that the reverse would be true ?

It sounds as if calico has a similar query to mine

Thanks

pentaxuser

prado333 · Tuesday at 1:29 PM

I usually Shot fp4 120 and always have the lettering gray . I use an ie 80 and underdevelop in Perceptol -15% or -20% . I think the important part is in the negative not the rebate

MattKing · Tuesday at 1:30 PM

pentaxuser said:
Well Matt some if us are simple souls who need help in understanding how different edge setting for different films work I certainly need help. So is it possible to explain to me exactly how a longer dev time for FP4 which has an HP5 edge setting imprinted on it by mistake results in a fainter edge marking when you'd think that the reverse would be true ?

It sounds as if calico has a similar query to mine

Thanks

pentaxuser

The developing time doesn't matter - as long as the developing time is matched to what gives good negatives with that film and that developer.
And don't you always give less camera exposure to HP5+ then you do for FP4+, in order to get good negatives? The edge printing machines are set to do the same. So if the machine is set for 400 ISO film, but there is only 125 ISO film in it, the edge numbers will be 1.75 stops under-exposed, and therefore faint.

And addressing @calico more generally, the ISO specifications for procedures for determining "Develop before" dates are based on all sorts of statistical "worst case" analyses.
Basically, the approximate two year lead time means that an exceptionally high percentage of film will still perform within narrow specifications for up to two years in almost all generally encountered storage and handling conditions - thus the choice of that period.
There are lots of older films out there that are still fine. And if you take care with longer term storage and handling, with one caveat, you can probably count on much longer life. Particularly with black and white film.
The caveat is particular to 120 film, in that backing paper adds a whole bunch of variables, and many of the steps taken to extend the life of unexposed film, such as refrigeration or freezing, actually increase the problems with backing paper interaction. Which is why I usually recommend cool, dry storage for 120 film, rather than refrigeration or freezing.

The other qualification to the foregoing is to remember that variable edge printing is not uncommon, and is not a reason to refrain from using film - it can still make entirely suitable pictures, whether or not the edge printing density has varied. It just isn't one of the factors considered when determining "develop before dates".

koraks · Tuesday at 1:30 PM

calico said:
But I always overexpose a little (100 ISO instead of 125) which would compensate for some underdevelopment

Not to this extent. Rest assured, your film looks well-cooked. That third of a stop isn't going to make much of a difference at all.

prado333 · Tuesday at 1:32 PM

Not outdated film shoot a week ago

pentaxuser · Tuesday at 4:20 PM

MattKing said:
The developing time doesn't matter - as long as the developing time is matched to what gives good negatives with that film and that developer.
And don't you always give less camera exposure to HP5+ then you do for FP4+, in order to get good negatives? The edge printing machines are set to do the same. So if the machine is set for 400 ISO film, but there is only 125 ISO film in it, the edge numbers will be 1.75 stops under-exposed, and therefore faint.

Thanks so are the edge markings specific to a named film or do they apply to the speed of the film i.e a 400 speed film ( be that HP5 or D400 ) edge marking wrongly placed on a slower film will always be 1.75 stops underexposed and thus fainter? Do edge markings reflect this kind of underexposure accurately i.e. can their depth of colour( shade of darkness) be measured accurately enough to verify that that is what happened in calico's case?

Could Ilford if given calico's film be able to say:" Mea culpa" it was our fault for putting another film's edge marking on your FP4?Your negs are fíne but the edge markings are wrong because we made the mistake of setting the edge setting for anohter higher speed film?

On that basis it sounds as if it will be worth calico's time to send his film to Ilford as it will, if willing to admit it made a mistake to say it has to be our fault for your edge makings to have turned out this way

On the basis on what you have said above I think it follows that the edge markings on any film will not vary in depth irrespective of in camera exposure so HP5 set at an EI of 1600 will not show any difference in depth of edge markings? Had you not realised that you had set your EI at 1600 and had developed the film for 400 then your frames will be both underexposed on purpose and underdeveloped by accident but the edge markings will remain the same?

So in that case the edge markings now tell you nothing of what you did wrong. You have to be able to work out from the negs that they are both underexposed and underdeveloped?

However you say above :
"The developing time doesn't matter - as long as the developing time is matched to what gives good negatives with that film and that developer."

So does that mean as long as the development time is right to give good negatives( albeit underexposed ) then the edge markings will remain the same? If good negatives can be achieved at different EIs by the correct development time then I am puzzled how in advance of the use of the film Ilford decides the correct edge setting Is that edge setting for a specific film made to give the correct shade of darkness for a whole range of E.I. s provided the development time used is correct for that E.I?

Do you know how llford sets its edge markings so that the depth of colour comes out "right" for want of a better word for that specific film as long as the dev time is matched to what gives good negatives with that film and that developer irrespective of the development time?

I am still finding it difficult to get my head how Ilford distinguishes different films or is that different film speeds within the range of edge settings it applies

Thanks

pentaxuser

calico · Tuesday at 5:22 PM

MattKing said:
And addressing @calico more generally, the ISO specifications for procedures for determining "Develop before" dates are based on all sorts of statistical "worst case" analyses.
Basically, the approximate two year lead time means that an exceptionally high percentage of film will still perform within narrow specifications for up to two years in almost all generally encountered storage and handling conditions - thus the choice of that period.
There are lots of older films out there that are still fine. And if you take care with longer term storage and handling, with one caveat, you can probably count on much longer life. Particularly with black and white film.

Interesting, thanks.

MattKing said:
The caveat is particular to 120 film, in that backing paper adds a whole bunch of variables, and many of the steps taken to extend the life of unexposed film, such as refrigeration or freezing, actually increase the problems with backing paper interaction. Which is why I usually recommend cool, dry storage for 120 film, rather than refrigeration or freezing.

I came to that conclusion, too, when I was dealing with the mottling on 120 FP4 around 2020. I stopped putting any 120 b&w film in freezer or refrigerator, just in case it worsened the backing paper issue.

MattKing said:
The other qualification to the foregoing is to remember that variable edge printing is not uncommon, and is not a reason to refrain from using film - it can still make entirely suitable pictures, whether or not the edge printing density has varied. It just isn't one of the factors considered when determining "develop before dates".

Good to know. This discussion about edge printing has been very educational. Thanks.

calico · Tuesday at 5:35 PM

prado333 said:
Not outdated film shoot a week ago

The edge info there looks pretty normal to me. The info in the roll I had questioned was barely legible (see first post, neg on the left).

MattKing · Tuesday at 8:01 PM

pentaxuser said:
Thanks so are the edge markings specific to a named film or do they apply to the speed of the film i.e a 400 speed film ( be that HP5 or D400 ) edge marking wrongly placed on a slower film will always be 1.75 stops underexposed and thus fainter? Do edge markings reflect this kind of underexposure accurately i.e. can their depth of colour( shade of darkness) be measured accurately enough to verify that that is what happened in calico's case?

Could Ilford if given calico's film be able to say:" Mea culpa" it was our fault for putting another film's edge marking on your FP4?Your negs are fíne but the edge markings are wrong because we made the mistake of setting the edge setting for anohter higher speed film?

On that basis it sounds as if it will be worth calico's time to send his film to Ilford as it will, if willing to admit it made a mistake to say it has to be our fault for your edge makings to have turned out this way

On the basis on what you have said above I think it follows that the edge markings on any film will not vary in depth irrespective of in camera exposure so HP5 set at an EI of 1600 will not show any difference in depth of edge markings? Had you not realised that you had set your EI at 1600 and had developed the film for 400 then your frames will be both underexposed on purpose and underdeveloped by accident but the edge markings will remain the same?

So in that case the edge markings now tell you nothing of what you did wrong. You have to be able to work out from the negs that they are both underexposed and underdeveloped?

However you say above :
"The developing time doesn't matter - as long as the developing time is matched to what gives good negatives with that film and that developer."

So does that mean as long as the development time is right to give good negatives( albeit underexposed ) then the edge markings will remain the same? If good negatives can be achieved at different EIs by the correct development time then I am puzzled how in advance of the use of the film Ilford decides the correct edge setting Is that edge setting for a specific film made to give the correct shade of darkness for a whole range of E.I. s provided the development time used is correct for that E.I?

Do you know how llford sets its edge markings so that the depth of colour comes out "right" for want of a better word for that specific film as long as the dev time is matched to what gives good negatives with that film and that developer irrespective of the development time?

I am still finding it difficult to get my head how Ilford distinguishes different films or is that different film speeds within the range of edge settings it applies

Thanks

pentaxuser

sigh
Changing development doesn't really change the sensitivity of film - at least not significantly.
People fool around with different EIs and different development times in order to make different uses of different parts of the characteristic curve, because there is more usable stuff at either end of the curve then we normally make much use of. When they do that, the parts of the scene that aren't a middle tone end up being in the negative either much less dense or much more dense than they would if the scene was metered at the ISO speed of the film, and developed normally.
The ISO speed is a decent measure of the film's inherent sensitivity - if you use that, and your light source and subject have typical amounts of contrast, then a normally developed negative, exposed when normally metered using the ISO speed, will end up with a middle density corresponding to where the subject has a middle tone, the less dense parts of the negative will correspond to where the subject has a shadow tone, and the more dense parts of the negative will correspond to where the subject has a highlight tone.
Most likely, the edge printing exposure is the right amount to create in a normally processed to ISO speed negative something close to a density akin to a highlight density.
If you change that exposure, that density will change, unless you screw around with the development in a way that will give you lousy shadow and mid-tone densities in your negative.
When compared to normal, suitable for regular ISO response development, If you over-develop/push develop film, the edge printing will end up with more density. And if you under-develop/pull develop film, the edge printing will be less dense.
But no one I know gauges the amount of development on their edge printing.

retina_restoration · Tuesday at 9:33 PM

calico said:
Yes, the images basically look fine. But I always overexpose a little (100 ISO instead of 125) which would compensate for some underdevelopment, and the images looked a bit less dense than those on the other FP4 roll with the dark edge info. So development, in my mind, seemed slightly ambiguous.

The difference

MattKing said:
But no one I know gauges the amount of development on their edge printing.

Nor should you. It is NOT a diagnostic tool for any kind of calibration effort.

koraks · 2025-07-23T01:18:44-0400

pentaxuser said:
Do edge markings reflect this kind of underexposure accurately i.e. can their depth of colour( shade of darkness) be measured accurately enough to verify that that is what happened in calico's case?

No.

FP4 edge info very light

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