Thoughts from a first time Rodinal user....

[gainer]

How much Borax p/Liter Rodinal 1:50? How does all this affect processing times?

Cheers
Daniel

Much of what you are asking about has been presented in tutorial articles in www.unblinkingeye.com in detail that would not be appropriate here. There are many other articles there on basic and advanced topics that could stir up discussion here. I'm not trying to be mean, just helpful.

 

[Gerald Koch]

Agfa Rodinal is nothing more then a nice, 'low contrast developer'.

I don't know how you can compare developers on the basis of the prints you obtain if the films used for the prints are not developed to the same contrast index. In addition, developer A's published development times are based on the manufacturer's assumption of a particular contrast index which may not agree with developer B's index.

Before you can make any sort of comparison you must eliminate all other variables in your processing. Obviously, you must use the same film for all tests. Films must be exposed under the same lighting conditions. Each film must be developed to the same contrast. Prints for comparison must be made from negatives with the same density since density will effect grain. All prints must be made with the same magnification. And so on ...

It's misleading to say that one developer is better than another. For example is Microdol-X better than Rodinal? Microdol is going to surpress grain at the expense of sharpness while Rodinal will emphacize sharpness while presenting the grain inherent in the film. It all depends on what you personally desire in you prints.

 

[gainer]

Testing many developers with the same film is one part of the story. Testing the same developer with many films is another part. It is not fair to say that one developer is universally better than another on the basis of tests with one film. Neither is it fair to say that one film is better than another on the basis of tests of many films with one developer. It is fair to report that a particular developer is better for a particular film than all others tested, if that is true. It is fair to report that a particular film is the best one to use with a certain developer on the basis of tests of many films with that developer.

In any case, the performance criteria should be specified and the results should be repeatable.