How much developer: dilution or amount or both?

crimbo · Oct 30, 2016

I am working with Rodinal but this should apply to other developers

Lets agree that a standard film area is 1x35mm(36) = 1x120 = 4x 4inx5in = 1x10inx8in

for example: I take 3ml of developer and add 300ml water = 1+100
Then I take 3ml developer and add 600ml water = 1+200

In each I develop a standard film area at the same temperature and time and agitation in each of the mixtures
Providing the film is identically exposed am I going to see any differences?

ta

Chris

BMbikerider · Oct 30, 2016

Tones may be compressed, contrast may be different, lack of some shadow detail. There may be others, including boredom with the extended developing times

Kevin Caulfield · Oct 30, 2016

Of course you will see differences.

markbarendt · Oct 30, 2016

Changing any variable: dilution, time, temperature, agitation, exposure, or film; changes the result.

1+100 will develop the film more, 1+200 will develop the film less; all else being equal.

Harry Stevens · Oct 30, 2016

I would suspect the developers would have lost all their steam after 20 mins........A 1+50 man myself.

Gerald C Koch · Oct 30, 2016

Harry Stevens said:
I would suspect the developers would have lost all their steam after 20 mins........A 1+50 man myself.

+1

This is the concentration that I use with Rodinal. Never had any problems. As far as 3 ml per roll I believe that Agfa recommended twice the amount of concentrate. If you wish to use it 1:100 or 1:200 then you have to compensate by using more of the working strength developer. Using the OP numbers that would mean using 600 ml of 1:100 per roll.

Leigh B · Oct 30, 2016

A 500ml bottle of Rodinal will develop 50 rolls* of film, per the instructions on the bottle.

So you must use 10ml of concentrate per roll, regardless of the dilution.

Rodinal is a compensating developer. It's meant to be exhausted in the dense areas of the negative.
That requires gentle infrequent agitation. This is critical to obtaining proper results.

If you use it in a rotary processor (e.g. Jobo), you will get unexpected and quite uncharacteristic results.

- Leigh

*NB: A roll is any film that can be proofed on a single sheet of 8x10 paper.
That is one 36exp 35mm roll, one 120 roll, four 4x5 sheets, one 8x10 sheet, etc.

Ian Grant · Oct 30, 2016

Rodinal is not a compensating developer if used as recommended by the manufacturer. It becomes a compensating developer if used at 1 to 100 or 1 to 200. Agfa used to recommend a minimum quantity of concentrate per film specifically so it wasn't exhausted during development.

Rodinal is fine with normal inversion agitation it doesn't require infrequent agitation. I used it for hundreds of rolls of 35mm and 120 film as well as a few thousand 5x4 negatives.

Ian

pdeeh · Oct 30, 2016

ah the Rodinal wars ... they are never quite extinguished. always flaring up. always some new belligerents willing to sabotage the peace process.

Pioneer · Oct 30, 2016

Now you guys have gone and screwed it all up for us poor neophytes.

I have been agitating Rodinal 1+50 and 1+25 just like I agitate D76. (1+100 was supposed to be done differently)

I thought I was getting damn good negatives and prints.

I am NEVER going to get this stuff right!!!

Leigh B · Oct 30, 2016

Ian Grant said:
Rodinal is not a compensating developer if used as recommended by the manufacturer. It becomes a compensating developer if used at 1 to 100 or 1 to 200. Agfa used to recommend a minimum quantity of concentrate per film specifically so it wasn't exhausted during development.

That's interesting.

I've used Rodinal for well over 40 years, on hundreds of rolls and perhaps thousands of sheets.

I always thought it was a compensating developer, and have negatives that seem to show that effect.
I do commonly use 1+100 dilution, so perhaps that's the reason.

- Leigh

pdeeh · Oct 30, 2016

Pioneer said:
I am NEVER going to get this stuff right!!!

Dan,if you are not doing it someone else's way,you're doing it WRONG

Gerald C Koch · Oct 30, 2016

http://mauglee.kitox.com/files/agfa_bw_film_chemicals_en.pdf

Looking at page 6 of the document Agfa recommends a dilution of 1:25 and 1:50. I believe that when Agfa stated that a 500 ml bottle would develop approximately 50 rolls of films they were talking about the 1:25 dilution. Still the documentation is not very clear. However many users like myself use 1:50 with no apparent difficulties.

Ian Grant · Oct 30, 2016

Gerald, you can see that Agfa published recommended times for Rotary processing as well. When I switched to Agfa films and Rodinal around 1986 I was very surprised that my Zone system tests matched Agfa's recommendations for AP25/AP100 with Rodinal., it was the same when they switched to APX25/APX100.

Ian

Leigh B · Oct 30, 2016

Gerald C Koch said:
I believe that when Agfa stated that a 500 ml bottle would develop approximately 50 rolls of films they were talking about the 1:25 dilution.

Gerald,

You mis-understand the spec.

The 50 roll capacity relates to the amount of concentrate used for each roll, not the final volume of working solution.

500ml of concentrate will do 50 rolls of film = 10ml / roll, regardless of how much water is present.

- Leigh

Gerald C Koch · Oct 31, 2016

Leigh B said:
Gerald,

You mis-understand the spec.

The 50 roll capacity relates to the amount of concentrate used for each roll, not the final volume of working solution.

500ml of concentrate will do 50 rolls of film = 10ml / roll, regardless of how much water is present.

- Leigh

As I said the directions are not very clear. From the Agfa documentation: "Rodinal is diluted with water as shown in the tables (1 part concentrate + 25 or 50 parts water." Nothing is said about using twice the volume of developer for the 1:50 concentration. So either interpretation could be correct.

Leigh B · Oct 31, 2016

Gerald C Koch said:
Nothing is said about using twice the volume of developer for the 1:50 concentration.
So either interpretation could be correct.

That's because you use the SAME amount of developer concentrate with different amounts of water.
That's how you get different dilutions.

BTW, it's 1+50 parts, not 1:50.

The final volume of mixed developer is irrelevant, except to be sure you have enough to fill the tank.

I don't understand your "either interpretation" statement since there's only one statement.

- Leigh

Gerald C Koch · Oct 31, 2016

Leigh B said:
That's because you use the SAME amount of developer concentrate with different amounts of water.
That's how you get different dilutions.

BTW, it's 1+50 parts, not 1:50.

The final volume of mixed developer is irrelevant, except to be sure you have enough to fill the tank.

I don't understand your "either interpretation" statement since there's only one statement.

- Leigh

Sorry I got lazy. Awhile back I and a couple of others championed use of the 'plus' notation.

A few years ago I calculated based on the amount of silver halide present in a fast emulsion and found that even at 1+99 and 250 ml there is more than enough PAP present to develop film correctly. As Ian pointed out if you want a compensating developer then you must use a dilution greater than 1:25. Here in Florida with its harsh sunlight I use 5 ml to 250 ml of working solution.

Agree to disagree.

Rich Ullsmith · Nov 1, 2016

The way I read OP is: if you are using the same film in different formats, i.e. 36 exposures of 35mm vs. 12 exposures of 2 1/4X 2 1/4 vs. four sheet of 4"X5", that is, the same area of film, can you expect the same results for a given development.

Ozxplorer · Nov 1, 2016

G'day... I'm wondering if there is some validity in the view regarding the minimum volume of developer needed per processing session based upon manufacturer recommendation of maximum number of films the stock solution is specified to develop (not to say that "pushing the development envelope" is never an option).

For instance, having recently produced my worst ever post development result of a film/developer combination of Ilford 36/35mm HP5+ and Ilford Perceptol diluted 1+3, (the film being totally underdeveloped). I used a Paterson tank. The total volume mixed for single use was Perceptol 100ml + 300ml water = 400ml, enough to cover the reel - so I thought: time was 25 minutes @ 20.5c plus agitation per the Ilford spec. sheet.

The title of this thread set me thinking... I re-read the Perceptol specification to find that Ilford recommend 1ltr of stock solution process only 4 films. Thus, it seems, in this instance, the volume developer needing to be used was 250ml per film and not the 100ml actually used. I assume therefore, the developer became exhausted before completion of development hence the severe under development.

Granted, Rodinal & Perceptol development actions differ. Rodinal, it seems, is capable of greater than specification dilutions - development time dependent. Whereas, in my recent experience, Perceptol needs a minimum quantity of developer per dilution to achieve full development.

Upon reflection, to process using a 1+3 dilution seems counter productive (larger grain) without an appreciable developer cost saving. I will have another try using freshly mixed Perceptol. This time, using a 1+1 dilution to 400ml thus, 200ml Perceptol developer - less than what I now believe to be optimal. Then, another test using using what I now believe to be the minimum developer volume - 250ml plus water to 500ml just to find out if there is much of a difference between the former dilution and this one. A densitometer might come in handy here...

Fred.

Kevin Caulfield · Nov 1, 2016

Ozxplorer said:
G'day... I'm wondering if there is some validity in the view regarding the minimum volume of developer needed per processing session based upon manufacturer recommendation of maximum number of films the stock solution is specified to develop (not to say that "pushing the development envelope" is never an option).

For instance, having recently produced my worst ever post development result of a film/developer combination of Ilford 36/35mm HP5+ and Ilford Perceptol diluted 1+3, (the film being totally underdeveloped). I used a Paterson tank. The total volume mixed for single use was Perceptol 100ml + 300ml water = 400ml, enough to cover the reel - so I thought: time was 25 minutes @ 20.5c plus agitation per the Ilford spec. sheet.

The title of this thread set me thinking... I re-read the Perceptol specification to find that Ilford recommend 1ltr of stock solution process only 4 films. Thus, it seems, in this instance, the volume developer needing to be used was 250ml per film and not the 100ml actually used. I assume therefore, the developer became exhausted before completion of development hence the severe under development.

Granted, Rodinal & Perceptol development actions differ. Rodinal, it seems, is capable of greater than specification dilutions - development time dependent. Whereas, in my recent experience, Perceptol needs a minimum quantity of developer per dilution to achieve full development.

Upon reflection, to process using a 1+3 dilution seems counter productive (larger grain) without an appreciable developer cost saving. I will have another try using freshly mixed Perceptol. This time, using a 1+1 dilution to 400ml thus, 200ml Perceptol developer - less than what I now believe to be optimal. Then, another test using using what I now believe to be the minimum developer volume - 250ml plus water to 500ml just to find out if there is much of a difference between the former dilution and this one. A densitometer might come in handy here...

Fred.

Sounds plausible, Fred, but don't overthink it.

Ian Grant · Nov 1, 2016

Gerald C Koch said:
Sorry I got lazy. Awhile back I and a couple of others championed use of the 'plus' notation.

A few years ago I calculated based on the amount of silver halide present in a fast emulsion and found that even at 1+99 and 250 ml there is more than enough PAP present to develop film correctly. As Ian pointed out if you want a compensating developer then you must use a dilution greater than 1:25. Here in Florida with its harsh sunlight I use 5 ml to 250 ml of working solution.

Agree to disagree.

In practical use I mixed Rodinal 1:25, 3:100 or 1:50, same as I now mix Pyrocat 1+1 to 100 because measures aren't accurate enough to mix to 510ml (for 1+50_ etc.

In practice with Rodinal I didn't like the tonality at 1:50 for normal use and only used the dilution for N-2 development, which is your harsh sunlight conditions, I preferred 3:100 for normal lighting (N use) and 1:25 for boosting contrast N+2.

I wouldn't even consider diluting Rodinal more than 1:50 with normal films, however with copy films high dilution can tame the contrast..

Ian

Leigh B · Nov 1, 2016

Ian Grant said:
...because measures aren't accurate enough to mix to 510ml (for 1+50_ etc.

That's why you use a small 10ml or 25ml or 50ml graduate to measure the concentrate.

- Leigh

Ricardo Miranda · Nov 1, 2016

There seems to be a lot of confusion above.
Might be good to read the datasheet bellow from Agfa.

Ian Grant · Nov 1, 2016

Leigh B said:
That's why you use a small 10ml or 25ml or 50ml graduate to measure the concentrate.

- Leigh

I prefer to add the developer first rinsing the smaller graduate into the larger one, it's about consistency rather than absolutes.

Ricardo Miranda said:
There seems to be a lot of confusion above.
Might be good to read the datasheet bellow from Agfa.

The German data-sheets don't recommend 1+100, however Agfa in the US used to, something the late Peter Goldfield pointed out many years ago in "The Goldfinger Craftbook for Creative Photography.

Ian

marcmarc · Nov 1, 2016

One of the the issues I have with Rodinal and their dilutions is I try to keep to the rule of thumb of 5ml of concentrate per roll. This is fine for a 35mm roll in a 500ml tank. However, when I want to develop a roll of 120 I have to use a 1000ml tank because the 500ml tank which will fit a 120 roll will require me to dump some of the working solution because at 1+50 I'll end up with 510ml of solution. With Rodinal being a speed decreasing developer I want good shadow detail so I'm reluctant to throw out any solution. In a 500ml tank I would need 400ml to cover the reel and still allow for space for agitation.

Gerald C Koch · Nov 1, 2016

My thanks to Ricardo who provided the Agfa data sheet. From it I get the statement "The RODINAL 1 + 100 times are only recommended for use in hand tanks. There should be a minimum of 250 ml’s of solution for each film in the tank." This certain works out as less than 10 ml of concentrate per roll.

How much developer: dilution or amount or both?

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