Help with adjusting my processing.

[Cluster]

I have a small stash of Fomapan 100, Fomapan 200 (bulk roll, yet untried) and Kentmere Pan100 all in 35mm.
I have at last settled down on just a few cameras for my future film use (but there's always a danger of GAS adding more).
Past anomalies in my image developing weren't worth trying to correct as these were thought to be down to the old cameras I was trying. Some only got a couple of films through them.

I have a few "fun" cams to use now and then, as their flaws can give a certain character to my images, but my proper work will be done on my Pentax and Cosina SLRs.

One thing has been fairly clear whilst processing film from all cameras, this is the apparent image difference between my main films, Fomapan100 and Kentmere Pan100.
The scan (below) of negatives that I would consider to be reasonably well exposed and of a good density for scanning, shows a consistent difference between them.
The left image is typical of Fomapan 100 and the image on the right is typical of several from Kentmere Pan100, both developed in 1:50 Rodinal 20c, 5 secs agitation/min at the dev time given in the massive dev chart. (Fomapan suggests 8-9 mins so gets 8.5min).

As you will see, the contrast on the Fomapan is much higher than the Kentmere. I will reduce the dev time of the Fomapan to try to calm it down a little, but by how much, and.. should I adjust the exposure?

Test scene (close focus) out of direct sunlight.

 

[Harlequin565]

I'm sure better informed people will be along, but my understanding is that pulling to reduce contrast requires over exposure and under-developing.

The rule of thumb I saw on the MDC was for every stop, reduce/add a third of time.

So if you expose the Foma at 50, and dev for 5.5 minutes that should get you in the ballpark. Unless there's an MDC time for Foma 100 at 50.

I prepare to stand to be corrected

Edit to add: All films have their own characteristics. For me, I quite like the look of Foma 100, it's just not flexible enough at 100 ISO - especially where I am One thing to consider is having a roll of each in your cameras and then picking the right film for the conditions. Obviously to do this, you need more cameras

 

[StephenM]

It would be good to see the negatives rather than the adjusted by scanning version. My best advice will be based on what I can see, and if I give my reasoning, you can see if I'm correct or not by examining the negatives.

Based on the image of the tap, it looks as if the upper image was relative to the lower, underexposed (lacks detail in the shadows). The contrast is excessive. If the tap does lack detail in the shadows, I'll go with increasing the exposure - development should be cut in any case. If the tap does in fact have the same level of detail in the shadows in both, then the development is excessive. You said that both negatives appear to be correctly exposed; if so, leave exposure alone and cut development.

The impression I have is that the first is definitely over developed, and development should be cut. I'll stick my neck out and suggest knocking at least 20% off the time. If the tap shadow areas have detail, leave the exposure as is, otherwise try 1/2 or 1 stop more.

 

[Cluster]

I should have added that both films were shot at box speed. I read in several places where Fomapan 100 is better at reduced speed but was waiting to get consistent results before making a change. The developer used for these is old Rodinal (10yr+). (A new bottle of R09 is on its way to me, so will change after a few more films).

 

[soupdragon]

I can't help you here but I rather like the high contrast image.

 

[trypdal]

Just to add to the excellent info you've already been given, a reminder that Foma's film curves provided in their technical data sheet here

https://www.foma.cz/en/fomapan-100

have most likely been calculated for a target gamma at or around .7. Traditionally, however (and for wet lab printing purposes) a standard gamma value to allow easy printing on grade 2 paper would have been in the region of .5-.6. Tracing curves at higher gamma is not inherently wrong by the way - it's similar to what Agfa used to do with their published curves.

You can observe this by yourself on page two of their pdf by interpolating, for a chosen developer, the curves at 20C to achieve box speed (or near). You will not be able to obtain box speed by starting at .5-.6 gamma values on the Y-coordinate axis. The example below is taken from the Foma 400 datasheet, but should give you an example of what I mean. For a target gamma of .7, Foma 400 can be developed in Fomadon LQN for 11 minutes at 20 degrees Celsius for an exposure index of 320.

Anyhow - target gamma ~ .7 means that processing for the times suggested in the data sheet will result in relatively high contrast negatives, which probably leads to what you're seeing. With Foma 100, I would always reduce development times by 10% or so, depending on developer, and especially if scanning your negatives (scanner CCDs do not need that extra density in the highlights and might produce exaggerated grain as well which can be avoided).

 

[Asha]

Based on the recommendations from other users of fomapan 100, I reduced development time by iirc 10% and found that the resulting negs lacked contrast to a point where even with a grade 5 filter and multigrade paper, I was struggling to get a decent print.
Scanning the negs was easier though even then a substantial boost of contrast was needed to bring the image alive.
The fomapan result of the tap that you show looks fine to me….. by contrast, pun intended, the result from the kentmere resembles similar to what I was obtaining by reducing development times.
As for film speed of fomapan 100, I’ve never had an issue exposing at box speed.

 

[trypdal]

Based on the recommendations from other users of fomapan 100, I reduced development time by iirc 10% and found that the resulting negs lacked contrast

That's odd. What was your choice of developer? Can you share a snapshot of the negative against some kind of even backlighting?

 

[StephenM]

From memory of what Asha has said, I'd guess HC110, continuous agitation in a Paterson orbital.

 

[Asha]

From memory of what Asha has said, I'd guess HC110, continuous agitation in a Paterson orbital.

That's odd. What was your choice of developer? Can you share a snapshot of the negative against some kind of even backlighting?

Precisely what Stephen quoted …. He knows my methods too well lol

HC110 ‘B’ solution as that’s what I always use at standard 20 Celsius.

Come to think of it, 15% reduction rings a bell so a dev time of 5mibs 6 secs as against the full 6 mins .

Either way , for me the results were too much “John Major” ( grey all over ! Pmsl ) as against b&w with nicely varied tones of grey.

I suspect that a neg could be located although I don’t keep notes so I’ll be working from memory as to which, what, where, when.

 

[trypdal]

No worries Asha. I suspect those Foma curves will be relative to only the few developers listed (some are their own, some generic/Kodak ones) so it's entirely possible that with HC110 and others not listed what was highlighted above won't apply. Ultimately it's about what pleases the eye and it's all a matter of taste for sure.