Successful regime for processing Fomapan R 100?

Tom Kershaw

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I just made my first attempt this evening at processing black & white reversal film without much success. The first developer seemed to work fine (formula https://www.photrio.com/forum/resources/fompan-r100-reversal-first-developer.227/ ) but when I looked at the film it wasn't fully bleached after 5 minutes - having re-read the Foma instructions I'm going to try 8 minutes.

Bleach was a permanganate & sodium metabisulphite solution. - made a mistake here, absent mindedness...

Another point, for the re-exposure step I simply used the room lighting in my darkroom which is 5 x 100W conventional incandescent lamps; I pulled the film off the reel and held the film at either end fairly close to the lamps and moved the film around (both sides) to give consistent exposure.
 
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Lachlan Young

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Tom Kershaw said:
sodium metabisulphite
Click to expand...

Sodium Bisulfate is what you should be using for the acidification. You need a 'strong' acid for the bleach to work.

And probably worth adding 20g/l Sodium Hexametaphosphate to sequester the manganese.
 

Raghu Kuvempunagar

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Permanganate is a strong oxidizer whereas metabisulphite is a reducer - they're like enemies of each other. In fact metabisulphite is used to remove excess of permanganate and is part of the clearing solution used in conjunction with permanganate bleach. When metabisulphite is added to permanganate solution the result is a weak bleach. Also, some insoluble manganese compounds will be produced which increase the risk of scratches on the already soft emulsion .
 
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Tom Kershaw

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Thanks yes. Thinking about it this morning I must have been suffering from a case of brain fade yesterday evening.
 

138S

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Please let me point a workflow I used to adjust reversal processing...

1) Take a sample scene and shot it 36 times with 35mm film. Ideal sample scene should have (say) 3 horizontal unifom bands with detail (top middle and bottom). Middle would be exposed at box speed, top and bottom can be be 1 stop more or less metered. Now you cut a sample strip from the roll for each try, you don't need to cut a full frame, this is irrelevant for the test, in (say) if you cut 40mm then you have a frame separation in the middle but for the test this is irrelevant.

2) Once you completed 1st development and stopped it then you can do the rest lights open, with chem in little trays of (say) 60mm size, you move the 40mm processed sample from one tray to the next with small tweezers... and you have a pot with water to clean the tweezers each time they are used.

3) In that way you observe the bleaching and second development work, you have a diagnostic of what may go wrong, and you may make a lot of test fast and spending a single roll. If you cut samples of some 40mm you can mount the resuts in frames and to judge the projection, which is a sound way to check if the slide was sound for your taste. Inspecting the sample on the light table is a good approach but once the slide is projected we see better what the thing is.


Mainly you have to adjust contrast, and when contrast is ok then you investigate what EI is the good one. For this reason exposing an scene with 3 bands is a sound way becasue for each processing ajustment (mainly first development time) you see the effect in three exposures, one for each band, so when you have the contrast ok that frame contains 3 exposures, giving a clue about what EI you should use as the base exposure for further refinements.

We also can shot 18 frames of the sample scene in 35mm, then in darkness we open the camera and cut the exposed section and save it, so we have the remaining of the roll for additional tests, 18 samples for processing adjustment (contrast) may be enough and the rest can be used to refine exposure, so with a single roll you may adjust a film type.

_________

Beyond that, a refined testing way is calibrating the sensitometry curves, and then onverlaying the curves provided in the Provia datasheet to adjust contrast exactly the same. Provia curve is offered in absolute exposure units, so light is measured before exposing the calibrtion strip (contact copy of an Stouffer T2115 wedge on our film) then we also have absolute exposure units in our curve, so comparing we judge the EI we have to use in practice to nail a similar look than with Provia, which will be a good starting point.

_________
 
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Tom Kershaw

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Update. It works... my film I'm experimenting with is slightly OOD (2012) so I need to expose for about 64 / 80 EI. However the developer works fine and the bleach seems to be completely functional. The "dark" part of the process I ran in my Jobo processor before unloading the film for re-exposure and then loading the film onto a stainless steel reel for the second development and fixing. I used a fresh solution of the '1st developer' for my 2nd developer.

Bleach solution A:
  • 750ml distilled water
  • 20g Sodium Hexametaphosphate
  • 4g Potassium Permanganate
  • distilled water to 1000ml

Bleach solution B:
  • 750ml distilled water
  • 50g Sodium Bisulphate
  • distilled water to 1000ml
Bleach use is A+B to make working solution, then used one-shot (250ml per film in the Jobo) I used 7 minutes @ 24C

Clearing bath:
  • 750ml distilled water
  • 30g Sodium Metabisulphite
  • distilled water to 1000ml
 

Anon Ymous

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Raghu Kuvempunagar said:
Congratulations!

I'm curious to know the stability of bleach solution A. If you plan to store it for sometime, please do let me know how long it remained stable.
Click to expand...
It will likely keep very well. This is something I'd like to try at some point, at a concentration higher than 4g/l. The most annoying thing when mixing permanganate bleach is dissolving permanganate. It takes a while and the solution becomes too dark, making filtration mandatory. Hexametaphosphate improves keeping properties of this bleach, but it will become weak in a matter of weeks. Definitely helps if you process a fair amount of film, or have accumulated some, but not for sporadic use.
 

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Tom Kershaw

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awty said:
Do both formula's work?
Click to expand...

Paul,

I'm not 100% sure of your question. Perhaps I haven't explained myself well. The bleach I've made up seems to work well, completely clears the film base on the exposed film etc. The developer I have made up also works well. The question in my mind is more related to how long the processes should take, particularly with regard to first developer time. I think the second developer is to completion.

Tom
 

Anon Ymous

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Do you have a densitometer? If yes, you can take readings from bracketed shots of a gray card, or simply a white piece of paper. This should tell you a lot about your process. Have a look at the Scala 200X characteristic curve for a point of reference. But in any case, if it looks good to you, then it is fine.

While we are at it, what's the minimum density of your film?
 

Jeremy Saint-Peyre

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Hello, if i may, i have some questions, i use a bleach with a part A = Potassium Permanganate (3g/L) and part B = Sulfuric acid 5%. Mixed equal parts, i need 8 liters, 12min at 20°C to bleach a 30,5m 16mm film.

I am wondering what use is the Sodium Hexametaphosphate ? Does it prevent the emulsion to soften ?

Thanks a lot !

Jeremy
 
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Tom Kershaw

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Jeremy Saint-Peyre said:
I am wondering what use is the Sodium Hexametaphosphate ? Does it prevent the emulsion to soften ?
Click to expand...

Hello Jeremy,
Thanks for your question. I haven't done much work on reversal since my post in January, but do plan to start some more shortly. While typing this I can see someone has answered the question. How are you processing the 16mm film?

Tom
 

Agulliver

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I have enjoyed success recently developing the 8mm cine film version of Fomapan R 100 - which I assume is the same as the 35mm film.

First development 5 minutes in Ilford Microphen with lots of agitation (twizzle stick on a 30 foot spiral reel)
Wash 5 minutes
Bleach (potassium dichromate in sulphuric acid) 5 minutes
Wash 5 minutes
Re-expose to daylight 2 minutes
2nd development Ilford Microphen in daylight by inspection to completion
Final wash 10 minutes
Dry

Works a treat. Almost as good as a laboratory machine processing in the "correct" chemicals.

I happen to have Microphen on hand and I work in school laboratories so can make up my own dichromate bleach. I don't think anyone has ever made a better reversal bleach. The caveat is that I know what I am doing and I can bring the bottle back to work for disposal when it's spent. I would imagine a more easily available bleach could be substituted.
 

Jeremy Saint-Peyre

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Tom Kershaw said:
Hello Jeremy,
Thanks for your question. I haven't done much work on reversal since my post in January, but do plan to start some more shortly. While typing this I can see someone has answered the question. How are you processing the 16mm film?

Tom
Click to expand...

Hello Tom !

So, here is how i do after loading the 30,5m reel :

1 - Pre soak in 20°C tap water.
2 - 1st developer is FOMATOL LQN (a cheap paper developer) 4L at 1+9, with 6gr of Sodium Thiosulfate Pentahydrate (both for overall density and to help get rid of the anti halation layer). Tap water, 21°C, 14 min, semi continuous agitation.
3 - BLEACH : Part A is 4L 0,3% Potassium Permanganate in distilled water. Part B is 4L 3% Sulfuric Acid with tap water. Total is 8L of bleach, 20°C, 12 min, continuous agitation.
- From here, everything is done under the normal light of the room
4 - Quick dip in tap water tank to remove the big part of the bleach.
5 - WASH : 1 min in running tap water 20°C
6 - CLEAR : 1,25% Sodium Metabisulfite : 4L (50gr in 4L of tap water, for a single use if my calcul are not wrong), 20°C, 1min no agitation.
7 - WASH : 3 min in running tap water 20°C

8 - Re exposure : in a water filled tank, at around 80cm, 100w lightbulb, 2min each side of the reel while spinning in the water.

9 - 2nd developer : re use the first one, after that you can recycle it.21°C, 5 min, semi continuous agitation.
10 - WASH : 5 min in running tap water 20°C.
11 - CLEAN : Final bath of tap water with 20% of white vinegar (itself being 10%/13%) because of the limestone in the water i have here.

12 - Let dry on reel under a cloth.

Here is the last one i've processed and digitalized (it is a sound post synchronisation, in french, as i wasn't planning to show it and mostly because my english is bad) : And an other one when i was reconditionning DS-8 in Super-8 for reloadable cartridges : (heavily edited with AviSynth)

The telecinema we use is a Moviestuff Retroscan Universal 2k, i'm not pleased with it as the dynamic range of the sensor is not very good (that, and the focusing, and other stuff... i am kind of picky), the film have a lot more detailed shadow that just end up full black one in digital... Wich is why i'll probably make my own telecinema soon, it will be slower, but better in range and definition and based on Denis Carl open source telecine : http://www.deniscarl.com/dokuwiki/doku.php?id=start.

I'm up for questions and certainly for advices/help !

Have a nice sunday !

Jeremy
 

DareFail

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Hi, I am new to the world of reversal process and I would like to ask for your advise please.
I have used the foma kit with some Agfa Scala films and the results were very good for my taste.
Now I decided to buy my own chemicals to develop a 8mm foma film.
I have read that foma uses LQR developer on their kit but.. The kit's dilution is 1+5 and the suggested dilution for LQR on another brochure is 1+10. A bit confused on what to do here...
I own the following chemicals and any suggestion is much appreciated.
LQR, sodium thiosulphate anhydrous, potassium permanganate, sulphuric acid 95-97%, sodium metabisulfate anhydrous.
Thank you!
 
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