N-1, N+1 percentage time changes?

[Sim2]

Hallo,

No doubt a muppet question here but.....

Are there "standard" percentage changes from Normal development for the N-1, N-2, N+1 and N+2 development?

I have seen varying figures from -10% to -20% for a N-1 development so was wondering if there is a "standard" percentage deviation that could be applied to the Normal development time.

Hope this makes sense. Thoughts and authorotive answers welcomed!

Sim2.

 

[glbeas]

The reason you see such a variance is developers are not alike in thier response to changes. The percents you see quoted are usually just a rough approximation used as a starting point for your own tests.

 

[heespharm]

Normal Minus To determine your Normal minus Development times, start with your new Normal Development Time and follow this procedure:

For your N - 1 time, multiple your new Normal time by 0.7. For your N- 2 time, multiply your new Normal time by 0.6.


For example, if your new Normal Development Time is ten minutes, your - 1 time would be seven minutes, and your - 2 would be six minutes.

Normal Plus To determine your Normal Plus Development times, the procedure is slightly different.

For your N + 1 time, multiply your new Normal time by 1.4. For your N +2 time, multiply your new N + 1 time by 1.4.

For example, if your new Normal Development Time is ten minutes, your N + 1 time would be fourteen minutes, and your N + 2 time would be 19 1/2 minutes


"Excerpt from Chris johnsons book"

 

[2F/2F]

There are no standards for all films and developers; there are only generalizations that work as starting points for experimentation or as "better than nothing" times in "salvage operations" for poorly exposed film. What I would do would be to look at a chart of manufacturer's recommended times that includes times for alternate EIs. If you do the maths, you should notice that all the +1's and -1's are close to a certain percentage over or under normal in any given developer.

 

[brian steinberger]

T-grain films N+ and N- development is going to be less than traditional grain films as well.

 

[Sim2]

Doh, beginning to wish I hadn't asked this

Whenever I seek to question what I know, the answers all seem to be "there is no standard, just have to test for every different scenario"!

Ho ho ho hum. Guess this is why b/w is so flexible in production.

Sim2.

 

[heespharm]

Yeah best way is to do your own tests... It's dependent on many factors including technique, chemical storage, water or any other variable that effect each persons individual dev technique...

 

[Brandon D.]

Doh, beginning to wish I hadn't asked this

Whenever I seek to question what I know, the answers all seem to be "there is no standard, just have to test for every different scenario"!

Ho ho ho hum. Guess this is why b/w is so flexible in production.

Sim2.

Well, anyone can give you a "standard" if you want, but there's just no guarantee that that "standard" will actually work for you. What you should be "seeking" is what will work for you. Be the expert of your own process. I like to think of it as I am the one who creates my own "standards." Otherwise, there'd be a lot less fun involved in the whole process. I think it's okay for the process to include fun and discovery.

 

[Stephen Benskin]

The rate of development varies with every film/developer combination. This rate can be graphed on a time/Gamma curve. Most manufacturers will include curves from a variety of developers with their technical data that accompanies each film.

Simply determine what your normal, plus and minus contrasts should be, then find the appropriate development time on the graph.

 

[piu58]

I can only speek for classical films. But there: It depends on the developer. Solvent devs need more "extra" time for N+1 in comparision to non sovent ones. Sovent devleopers solve back silver, mostly because of the hight content of sulfite.
I take 15% time difference for each step, using Rodinal, which is a non solvent dev.