<< I've done this before and it works more or less for a few steps. However
the real problem if you haven't go a densitometer is in deciding what is
density 0.15.
Actually the original density does not even have to be 0.15 as long as one
process the film with the right gradient so that the final wedge has
approximately 0.15 difference in each step.
>> Its actually easier to do a test strip or strips at various times,
develop, measure the densities, draw a curve of density v time and read
off the times you need for the 0.15 steps under the same conditions.
>>
Yes, and I have made many of my own step wedge this way. But if anyone is
trying to do it this way, you must make sure that your processing
(temperature, agitation, etc.) is fairly repeatible. I use automatic processor
(Jobo).
Dave