MichaelSt
[size=small]Good evening everyone,[/size]
[size=small]After decades, I’ve returned to analogue photography, but this is my first time conducting the development of black-and-white medium-format film.[/size]
[size=small]I am using Rodinal diluted 1:50 (1x FP4+) and filling the 1520 Jobo tank with 500ml of developer solution for one medium-format film.[/size]
[size=small]Now to my questions: [/size]
[size=small]Do I need to change the dilution ratio, i.e. use 1:25, if I want to develop two medium-format films? As I understand it, with the same amount of developer, there won’t be enough active developer in the tank for two films…[/size]
[size=small]If so, do I stick to the same development parameters (FP4+, 18°C, 19.5 mins development time) despite using a 1:25 dilution?[/size]
[size=small]Many thanks for your help[/size]
[size=small]Michael[/size]
KlausWehner
Hi Michael,
A minimum amount of developer is required per roll of film.
For Rodinal, this is 10 ml.
With a dilution of 1:50, this gives you a developer volume of 500 ml.
For a second roll of film, you’ll need the same amount again (10 ml Rodinal plus 490 ml water).
If your developing tank can’t hold 1000 ml, you could choose a different dilution.
So if you develop at a dilution of 1:25, 20 ml of Rodinal (the minimum amount for 2 films) will give you a final volume of 500 ml. That fits two films in a standard developing tank (e.g. Jobo).
Best regards
Klaus
MichaelSt
Hi Klaus,
Thank you very much for your quick reply.
So now I know what to do...
Best regards,
Michael
KlausWehner
Hi Michael,
I’m glad the issue was sorted out so quickly.
I’m always delighted when someone wants to get started with analogue photography.
Of course, there are always lots of questions at the beginning.
It helps everyone if you ask these questions here, as many others will have the same or similar queries.
Especially at the start, it’s important to avoid making mistakes in your workflow.
So always ask questions and perhaps share your first results at some point.
Good luck!
Best regards,
Klaus
musikbaer
Hello,
As a beginner, I’m currently developing my film using 5ml of Rodinal in a 250ml Jobo canister. Based on what Klaus, a professional, says, I’m wondering what I might expect – apart from shorter development times – if I were to use 10ml, i.e. a 1+25 ratio?
Best regards,
Marian
[attachment=3438]
KlausWehner
Hi Marian,
Below a certain concentration, there is no longer enough developer available to perform full development of the film.
As a result, exposed silver halide crystals in the emulsion remain undeveloped, even though they have been exposed during exposure.
The highlights have the highest density in the negative. Consequently, this is where the effect is most pronounced.
This results in the gradation curve no longer being linear, but instead kinking in the upper range.
However, the shadow area can also be affected.
In this case, a loss of speed would be noticeable.
Not all films react in the same way.
High-quality and silver-rich films are particularly affected.
The financial outlay for an extra 5 ml of Rodinal is very small indeed.
In return, you gain the assurance that you have developed your own films correctly.
Best regards
Klaus
