dev temperature vs contrast

[pierods]

I just finished reading a book by French author Philippe Bachelier, where he says that higher dev temperatures give film more contrast.

On the other hand, I remember reading in "Edge of darkness" (specifically when talking about perceptol 1+3) that development is equivalent when time is corrected for higher temperatures (shorter time, that is).

So, if I use higher temperatures for development and correct time, do I get an equivalent negative or a negative with more contrast (or somehow different)?

 

[Ian Grant]

Both are right in a way.

Certain types of developer, particularly MQ (Metol/Hydroquinone), don't work well at low temperatures, below 18°C, and the results are flat lifeless negatives.

However in practice nearly all developers can be used between 20°C-30°C just adjusting the time to compensate for changes in temperature, the coefficient/amout of change is not the same for all developers.

Ian

 

[Snapshot]

I always worked with the assumption that development is equivalent when corrected for time. So far, I haven't seen anything that would contradict that assupmtion. However, I would imagine there are exceptions to the rule.

 

[df cardwell]

The only exceptions when, as Ian points out, some developing agents are inactive at cooler temperatures.

Bachelier and Thornton were talking about the same thing, but to different purpose.