FP4 Exposure Mistake: Developing Suggestions

Svenedin · Sep 11, 2016

I have made a basic error with the exposure of a roll of 120 FP4+. I accidentally exposed half the roll at ISO 400. I then realised and exposed the other half of the roll at ISO 125.

The photos are of the Three Peaks in the Italian Dolomites in 6x7 format. I would like to try to get the best possible quality from the negatives and I cannot do the hike again.

As I see it, I have 2 choices. I can either develop the roll as normal for ISO 125 and accept that half the roll will be nearly 2 stops underexposed OR develop the roll for ISO 200 and compromise for the whole roll.

Does anyone have any views or experience of results from this kind of mistake? I am inclined to develop for ISO 200.

Dali · Sep 11, 2016

I would try a developer giving a little push, Microphen maybe. Or the ultimate solution would be Diafine which give acceptable results through a wide range of exposure.

Svenedin · Sep 11, 2016

Yes. I have Ilford DD-X or Kodak Xtol. I was considering using DD-X for the time Ilford recommends for ISO 200.

removed account4 · Sep 11, 2016

200
i've regularly over xposed and/or over developed the same film
but i use either home brew caffenolC or sprint film developer
never have trouble.
since you have xtol, you might use that, its a much less harsh developer.
ive never liked it because it refused to let me build up density which might be helpful in your situation.

something you might try is buy another roll or 2 expose it the same way, half at 400 and half at your
regular speed, in the same sort of bright lighting and develop a few test rolls in whatever way you had hoped would work the best
and see what you like best. dry runs of film that isn't "the important roll/s" are helpful. why run the risk.

good luck with your situation !
john

Svenedin · Sep 11, 2016

Good to hear you have found this film forgiving. When I realised my mistake I did wonder whether it would have been better to just carry on and expose the whole roll at ISO 400 but I thought it was better to change to the correct film speed and get something than risk getting nothing.

LAG · Sep 11, 2016

Svenedin said:
I accidentally exposed half the roll at ISO 400. I then realised and exposed the other half of the roll at ISO 125. ...

As I see it, I have 2 choices...

Excuse me

Exactly 5/5 each? (or speaking idly) In that case you have more choices... Anyway, if I were you and had to develop the roll in one go to get the best, I would save half

Gerald C Koch · Sep 11, 2016

I would suggest going with Diafine. I use a two bath developer with films exposed in simple cameras which have no exposure control. Every negative on a roll is either under- or over-exposed. A two bath developer seems to even things out a bit. If the negatives are irreplaceable then the added expense of Dafine is worth the money.

Bill Burk · Sep 11, 2016

I'd have taken the roll out and set it aside once I noticed the mistake... But I understand you can't go back.

I think you might try to develop as for 400, then after you get the results, if the correctly-exposed film has promising photos... and they are unprintable on the very lowest paper grades/filters... You could use a reducer.

NedL · Sep 11, 2016

Gerald C Koch said:
I would suggest going with Diafine. I use a two bath developer with films exposed in simple cameras which have no exposure control. Every negative on a roll is either under- or over-exposed. A two bath developer seems to even things out a bit. If the negatives are irreplaceable then the added expense of Dafine is worth the money.

This is what I'd try too. If you want to be careful, you could try as John suggested and see how diafine does with a test roll.

MattKing · Sep 11, 2016

Svenedin said:
As I see it, I have 2 choices. I can either develop the roll as normal for ISO 125 and accept that half the roll will be nearly 2 stops underexposed OR develop the roll for ISO 200 and compromise for the whole roll.

No matter what, you will end up with a roll where nearly half the roll will be nearly 2 stops underexposed.

Your choices are to:

1) develop to optimize the frames exposed at an EI of 125. Those frames will have good shadow detail and good contrast and good highlight detail. The frames exposed at an EI of 400 will have poor shadow detail, low contrast in the near shadows and mid-tones and decent detail and contrast in the highlights;
2) push develop ( ~2 stops to EI 400) the film. The frames exposed at an EI of 125 will have excellent shadow detail, skewed contrast throughout the range, and potentially blocked up highlights. The frames exposed at an EI of 400 will have poor shadow detail, enhanced contrast in the near shadows and mid-tones and enhanced contrast in the highlights;
3) push develop (~2/3 stop to 200). The frames exposed at an EI of 125 will have excellent shadow detail, slightly skewed contrast throughout the range, and potentially slightly blocked up highlights. The frames exposed at an EI of 400 will have poor shadow detail, middling contrast in the near shadows and mid-tones and slightly enhanced contrast in the highlights;
4) use Diafine, and end up with better shadow detail in the EI 400 frames, but fairly low contrast throughout.

My guess is that the scene had fairly high contrast. If so, a lower contrast choice may be a good one.

timmct · Sep 11, 2016

Figure where your division is...cut the film...develop accordingly at both ends.

Or go another way.

Mild overexposure in combination with mild underdevelopment is always what a film geek wants.

Bill Burk · Sep 12, 2016

I just developed a roll of TMY-2 rated at EI 250 where I had spotmetered the people on stage and used the reading as-is (technically I should have "placed" the reading on Zone VI by giving one additional stop of exposure... but then I under-rated the film so that EI 250 rating canceled out this mistake).

Then I decided 1/60 second at f/1.4 for the ceremony and started taking pictures.

After a couple shots I found the camera was set at 1/250 second and f/2. No matter, I was just warming up anyway. I set 1/60 and 1.4 and proceeded through two rolls.

Because the ceremony was very flatly illuminated I decided to develop the film to 0.72 CI, and my properly exposed shots taken at 1/60 all look great.

The underexposed shots look lousy. Thin and barely visible detail.

Just suggesting... 2 stops is a pretty bad underexposure... you might not get anything for those shots.

Frank53 · Sep 12, 2016

There is not much that stand development won't fix.
Rodinal 1:100 1 hour.
Some agitation halfway if you feel like it.
Regards,
Frank

Ashfaque · Sep 12, 2016

Sven, cut the roll in half and go from there. Sounds like it is an important role to you.

Best wishes,
Ashfaque

Svenedin · Sep 12, 2016

Thank you for all of your suggestions. I have never used Diafine but it does seem like a good idea. A quick search suggests it is not readily available in the UK. It is also expensive. Does it keep?

pdeeh · Sep 12, 2016

not readily available?
Ag photographic show it

bernard_L · Sep 12, 2016

Advise against Diafine. Following my recollection, that developer will kill the highlight sparkle. Possibly OK for street photo, not for lanscape.

Dali · Sep 12, 2016

I agree, it gives pretty flat negatives but contrast is not the OP #1 issue there.

And yes, Diafine is expensive but it lasts forever.

Svenedin · Sep 12, 2016

pdeeh said:
not readily available?
Ag photographic show it

Yes they show it but it is not in stock. I would have to enquire about availability.

I climbed 4,000 feet today (to over 8,000 feet) I have taken some more pictures of the Drei Zinnen (Three Battlements) with correct exposure. The hike up and down took over 6 hours. The pictures are not from as close as the mistake shots but at least I should have some reasonable photos. I did take back ups on 35mm anyway.

pentaxuser · Sep 12, 2016

Svenedin, please show us the pictures after developing, letting us know in this thread what developer regime you followed.

We can learn a lot from this

Thanks

pentaxuser

Eric Rose · Sep 12, 2016

Just cut the darn roll in half and be done with it.

sedwards · Sep 12, 2016

I have printable negatives from FP4 in Diafine from when I first started out and thought I didn't need to use a meter or think about exposure...

Svenedin · Sep 13, 2016

Eric Rose said:
Just cut the darn roll in half and be done with it.

I could do that but I might cut right through a frame.

LAG · Sep 13, 2016

Svenedin said:
I could do that but I might cut right through a frame.

Not necessarily (that's why I asked before you if both ISO/halves were exactly 5/5?). Anyway, "it's always better to lose one than many", but that's up to you.

Svenedin · Sep 13, 2016

LAG said:
Not necessarily (that's why I asked before you if both ISO/halves were exactly 5/5?). Anyway, "it's always better to lose one than many", but that's up to you.

I am not entirely sure it is exactly 5/5. I was hiking on rocky paths at high altitude and had a lot else to think about. To be perfectly honest, I am not sure they would have been great photographs anyway. The lighting was difficult, the sun almost directly ahead. I managed some shots when the sun was temporarily obscured by cloud but even so it was far from ideal. I did expose some shots at +1 and +2 stops to try to bring the subject out of shadow so the film is going to be a very mixed bag even without my stupid, careless mistake. I have taken a lot of pictures on this 10 day hiking trip so I will not be too upset if these particular photos are terrible. I have had worse over the years. On more than one occasion I have idiotically taken 36 shots on a 35mm roll only to find that the film had never engaged properly so it was not exposed at all. I never make that particular mistake now! One lives and learns. There is a lot to be said for only using one type of film! No film speed mistakes!

FP4 Exposure Mistake: Developing Suggestions

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