N+1=150% of development?
Extending (or shortening) development times by as much as 150%, 200%, etc., is essentially pushing (or pulling) the film. With Zone System N+ or N- development, the goal is not to push or pull, but to gently tweak the contrast level to fit it into the range the film or paper can hold.
Henry, a few things:
Originally Posted by henry finley
1) Adams ultimately settled on HC-110
2) Generalizing about curve shapes based on the developing agents is an incorrect approach. Little can be said about the characteristics of a developer without looking at the concentration of developing agent(s), the concentration of preservative (Sulfite) and the concentration/type of alkali (pH, buffering). As an example, G. Haist (Kodak) created a modified version of D-76 with identical working characteristics (but less capacity) by slightly increasing the amount of Metol (Elon) and omitting the Hydroquinone entirely. D-76 is a fine grain developer very similar to D-23 in practice.
3) Microdol is said to be D-23 with a little less Metol (5g/l rather than 7.5g/l) and somewhere around 30g/l Sodium Chloride. Microdol-X contained at least one extra ingredient - an anti-silvering agent.
It's a concentrated syrup. The exact formula is proprietary but based on the published patents and MSDS the developing agents are Phenidone (or one of the Phenidone derivatives) and Hydroquinone. It is a traditional favourite of Zone System users, mostly because Adams was using it in the 70s/80s, and because it is easily diluted to different working strengths. It also last a long time. The working characteristics are very similar to D-76.
I have found that N+1 time is usually 25-45% longer than N time. Most films gives N+1 around +30% time.
N+2 is hard to reach with my methods. Perhaps it could be something like 150% =)
I use slosher for sheet film with D-76 1+1 at 20°C. For roll film I use normal tank and inversions.
If I would really need N+2, I would do test set with some stronger developer for N+ times.
The other thing that he asserts is that we should always be able to print on grade 2 if we use the Zone System. I have heard this other places but I have heard if refuted. Even Adams said that some people consider grade as their "normal" grade. Since I switched to the Zone system, I have noticed that I generally used grades from 2-3.5. I have color enlarger in my darkroom so I can go down 1/8 grades. I am happy with the prints I have been producing with this. Also, if your negative is perfect, why would you need to dodge and burn which I use extensively. I like my prints so none of this really matters but I am rather curious on thoughts about all of this. I must keep in mind that my instructor says we should never crop and that the square is more difficult to compose.
In particular, the notion the Zone System leads to perfect negatives that require no burning, dodging etc. is preposterous. The "perfect" negative is one that contains all the information you need to make the print you envisioned or "visualized" when making the photograph. Straight prints are very uncommon, even with great negatives. Adams put a lot of effort into his prints, and used whatever grade of paper he needed. Many of his more famous images were printed on grades other than 2.
The Zone System is not an easy way out. It is simply a tool to help you get more predictable results.
Never crop? Why not? The "never crop" thing is just an attitude or personal mantra. It means nothing.
The instructor seems like a stubborn, opinionated person with not much actual technique to teach. Unfortunately in an academic setting you've got to do what the guy says for now so you get a good grade.
this is exactly rightandshould be taught as the first commandment of the zone system. this would avoid much confusion from the start:whistling:
Originally Posted by Michael R 1974
Originally Posted by RalphLambrecht
A good place to get a feel for the rate of development of any film/developer combination is from the manufacturer's time/gamma curves.