Development reduction scale

[Dr5]

Hello all. Was wondering if anyone has created a development reduction scale using potassium bromide. A metol/hydroquinone developer is being used. This is for an experiment I'm conducting. Thanks, dave w

 

[Bill Burk]

Do you mean time-gamma curves for a film with effective speed change with changes in formulation of the developer? No haven't done it but always thought it would be a worthwhile project for someone to undertake.

Sometimes I think that Potassium Bromide might be responsible for some different recommended development times in developers similar to D-76

 

[Gerald C Koch]

In older photography texts you can find lists of what is called the bromide potential π. The bromide potential gives the relative amount of development suppression for an amount of bromide versus various developing agents. The larger the value of π the more sensitive the developing agent is to bromide concentration. Hydroquinone is arbitrarily set equal to 1.

 

[Dr5]

..I'll have a look in some old text. Was hoping someone has made a hard test. But I guess I'll add 1gram to each test and see what happens. Best, dw