Developer Dilutions: A Basic Question

[Max Power]

I have a basic question about relative dilutions of developers.

All parameters being equal (agitation, temperature, etc), is it a general rule that the lower the dilution (higher the concentration of developer), the higher the acutance, the higher the contrast, the more pronounced the grain?

Thank you,
Kent

 

[Max Power]

Hi Max.

Acutance developers are typically very dilute, and since contrast is a consequence of development, more contrast/development=more grain, generally speaking.

Jay

OK Jay,
So, in theory, the longer the development, the more the grain will be visible?

Kent

 

[David H. Bebbington]

I have a basic question about relative dilutions of developers.

All parameters being equal (agitation, temperature, etc), is it a general rule that the lower the dilution (higher the concentration of developer), the higher the acutance, the higher the contrast, the more pronounced the grain?

Thank you,
Kent

The more you dilute developer, the slower it will work, therefore recommended times for dilute developer (e.g. D76 1+1 or 1+3) for a given film and desired contrast are longer than for stock (undiluted) developer. Stock developer can also achieve a higher maximum contrast if you want it to (and develop for a suitably long time). If you compare stock and dilute developer, developing in each case for the recommended time for a given contrast (average gradient or G bar), you will find that stock developer has a greater solvent action and thus gives finer grain, while dilute developer has less of a solvent action and gives slightly better sharpness. As dilute developer contains less active developing agent, its action will slow slightly in the densest areas of negatives and the dilute developer will thus give a slight compensating action (it will bring out shadow detail slightly more while not allowing highlight detail to become excessive). This compensating action can be encouraged by developing for longer in dilute developer with less agitation after the first minute.