Minimum Time Maximum Black Test With Traditional Negatives

[susanholstein]

I'm getting set up for platinum palladium printing and need to know my base exposure time for my film and paper combos with traditional negatives. I read that you are supposed to develop an unexposed piece of film and develop it to use for the test. My question is does the developing time for the film matter? For example, would I use my N, N+1 or N+2 time, or does that matter?
For reference I'm developing in pyrocat hd 2:2:100.

Thanks!

 

[Bob Carnie]

Susan when I was printing Pt Pd from in camera negatives , I always gravitated to a negative that was more contrasty than what I would consider a normal negative... If a normal neg in my darkroom printed at grade 2 1/2 I would make a negative that required a 1 grade.

Vaughn will probably chip in here as he is still doing this and has been doing this for a very long time and I would defer to his guidance..

 

[faberryman]

It doesn't really matter as long as the film is unexposed. You are only trying to determine the density of the film base plus fog.

 

[Vaughn]

I use an already exposed/developed negative to test for minimum exposure for black -- when the negs' rebate is as black as the area outside the negative in a print, then you have the minimum exposure for a black. If you use a fresh un-exposed piece of film to test with, use whatever is your usual development method, as that will determine the amount of fog (if any) you will have.

 

[susanholstein]

Thanks for your help everyone!
Ok that makes sense because you would just be looking for the point at which the line of the rebate disappears, same as you would if you used an unexposed piece. Thanks so much, that saves me a step.

 

[Vaughn]

Great! Sometimes it is nice to keep the exposure at the point where the rebate is just a touch lighter than the pure black outside it when wet, but drys down to the same black. Have fun!

 

[Slixtiesix]

There is no need to waste a roll of film, just use the film leader. Don´t forget the dry down effect if you are working with FB paper.