N- and N+ Development Question

[IanBarber]

When people refer to N- and N+ I know they are either extending or shortening the development time but when they say N-1 or N+1 (what does the 1 mean) in terms of development. Does it mean 10% ?

 

[Stephen Benskin]

Normal usually refers to developing the film for a 7 or 7 1/3 stop subject luminance range. N+1 is developing for a 6 or 6 1/3 stop luminance range. N-1 is developing for a 8 or 8 1/3 stop luminance range.

 

[IanBarber]

So if you want to apply N+1 to bring the luminance range up to 7 stops, how much extra development time would you give it

 

[Stephen Benskin]

It depends on the film / developer combination. The film manufacturer has a time/gamma curve and most developers come with recommendations. Some people will claim it's 30%, but that's a rule of thumb at best.

 

[Ian Grant]

It's more like a 20% shift in developing time going to N+1 (increase) or N-1 (decrease) with typical developers. Usually it's done by testing.

Ian

 

[Doc W]

What Stephen said. This is based on shadow detail and highlights and works something like this. If you measure a scene and find that the range from detailed shadow to highlight is 7 stops, you are ok. If that scene is only 6 stops, you can increase development to expand the range and get brighter highlights. If you measure 8 stops, then you reduce development to bring the highlights down one stop. You have to test development times in order to determine by how much you need to increase or decrease. It is not that complicated, although you can make it as complicated as you like!. I used to get pretty worked up about it and tended to over-test, but that need not be the case.

 

[Andrew O'Neill]

I usually place my important shadow on Zone III. If the detailed highlights fall on Zone VII and I want Zone VIII, then I'll give N+1 (time predetermined by testing) and N-1 if those important highlights fall on IX and I really want VIII. It's really important to do N tests and remember that the Zone system is not pin point science.

 

[MattKing]

It would be informative and it might be useful to poll Zone System users here on APUG what their N+1 and N-1 adjustment percentages are.

It does, of course, depend highly on what they are printing on.

 

[Old-N-Feeble]

I agree, Matt. It would be interesting to learn how much others adjust their development times (on average) to achieve N-2, N-1, N, N+1 and N+2. I suspect it matters less the film/developer combination than what many people believe... though very short development times may be affected more by initial infusion than longer times.

 

[tedr1]

This is perhaps not technically sophisticated but I think of it in terms of stops and film speed. If I want to shoot at double the film speed, from ISO100 to ISO200, this is achieved by extending the development time using +1 development, +1 stop of speed. The film and developer combination comes with instructions for film speed, chose the development time for the desired film speed, in this case ISO200 instead of ISO100.

 

[Ian Grant]

No the film/developer combination can be quite critical, some films build up contrast very much faster than others a good example is Fomapan films.

With developers like Rodinal while N+1 or N-1 are best controlled by development time, N+2 or N-2 are far better controlled by dilution as well, increasing the strength for N+2 and greater dilution for N-2.

Ian

 

[MattKing]

This is perhaps not technically sophisticated but I think of it in terms of stops and film speed. If I want to shoot at double the film speed, from ISO100 to ISO200, this is achieved by extending the development time using +1 development, +1 stop of speed. The film and developer combination comes with instructions for film speed, chose the development time for the desired film speed, in this case ISO200 instead of ISO100.

That is dangerous ground!

I say this because you aren't really increasing film speed (much) by increasing development. You are taking a scene with normal or high contrast and increasing the contrast of the near shadows, at the cost of loss of detail in the full shadows and the highlights.

N+1 development is used for a subject that is inherently low in contrast. It leaves the shadows and highlights with full detail, while increasing the full range of densities in the negative and the micro-contrast in parts of the negative.

 

[tedr1]

Thank you for reminding me that the development time change directly affects contrast and only indirectly affects speed. I believe the concept of stops remains helpful, contrast can be expressed in stops of tonal range, and the N+X concept fits with this quite well.

 

[Stephen Benskin]

Here is a Time / CI curve for six films. The horizontal line at 0.58 is considered normal development.

 

[Luis-F-S]

Simple: The 1 refers to 1 Zone.

N+1: over develop a Zone VI exposure to a Zone VII density value (or Zone VII to Zone VIII, etc.), so you make a Zone VI exposure and you over develop it to a 1.15 density over film base plus fog as measured with a densitometer.

N-1: under develop a Zone VIII exposure to a Zone VII density. So you make a Zone VIII exposure and under develop it to a 1.15 density over fb+f.

The not so simple part is to determine the developing times. The only way to determine is to test and test and test. Other people results are not transferable, your mileage will vary.....there are entire photography sensitometry books written about this. Sensitometry for Photographers by Jack Eggleston; Practical Sensitometry by George L Wakefield; among others.

 

[RobC]

Adams says the target zone fo N+ or N- is zone VIII and N+1 means zone VII pushed to zone VIII and N-1 means Zone IX pulled to Zone VIII.
So it seems evryone either can't read or hasn't read the negative or they are alll devising their own personal take on the zone system. Its no wonder its so confusing when everybody interprets it a different way.

 

[Luis-F-S]

It's not confusing, N+1 is a one zone expansion, and N-1 is a one Zone contraction. Which zone you choose, Zone VI, VII, or VIII is not that important. I follow Oliver Gaglianni's methodology as he taught it and he was one of Adam's pupils in the California School of Fine Arts (Photography) in the 1940's (see The Moment of Seeing, Minor White at the California School of Fine Arts by Stephanie Comer & Deborah Klochko, page 29).

Oliver used Zone VII because there is very little textural information in Zones VIII & Zone IX and None in Zone X. Fred Picker was also one of Oliver's students and he tried to simply it in his Zone VI Workshop since most photographers will never spend the time required to do the testing required to actually determine developing times for the different film/developer combinations, much less times for expansions and contractions.

 

[Bill Burk]

Luis-F-S has got it pretty well explained.

I'll try to explain but don't know whether I'll make it more clear or less...

N means Normal and that's when all the 10 Zones of the Zone System fall where they normally do. In other words, you are developing to get all the Zones.

Stephen's not counting the extreme Zones so he says 7 or 7 1/3 (I do the same thing but I'll admit it's not common core Zone System teaching, it's a translation of what Zone System is trying to do... into a different number system that is better suited to picking development times.)

N+1 means developing longer. How much longer? Enough longer to make a high zone fall one zone higher on the negative. It's an abstract that isn't an amount of time, it's a result you want. You decide the result you want in advance, for instance by measuring with a spotmeter and deciding you want something to come out "One Zone Higher" than it normally would.

Likewise N-1 means developing less, enough shorter time in developer that a high zone falls one zone lower on the negative. So for example Zone VIII falls on Zone VII (and something brighter like Zone X which normally wouldn't make it on the print at all, has a chance to show since it will be where Zone IX usually sits.)

 

[Dismayed]

I agree, Matt. It would be interesting to learn how much others adjust their development times (on average) to achieve N-2, N-1, N, N+1 and N+2. I suspect it matters less the film/developer combination than what many people believe... though very short development times may be affected more by initial infusion than longer times.

My development times are based on densitometer readings. They are not based on what I believe.

 

[Stephen Benskin]

Degree of development is sensitometry plain and simple. It is derived from the principles of tone reproduction. N+1, N, or +1 nomenclature is not inherently Zone System terminology and can be applied to methodology far less vague than the Zone System.

My apologies to the OP as this will probably be more advanced than you wanted. Degree of development is a process of matching a scene's luminance range to a paper's log exposure range. It's about the exposure input onto the negative and density output after development. Using a step tablet and 5 or more exposures, one can determine an adequate range of development for a given film / developer combination. All you have to do is determine the film's average gradient for a given processing time and plug it into the simple equation of Rise / Run. So, for an average 7 stop scene to be printed on grade 2 paper with an LER of 1.05:

1.05 / 2.1 - 0.30 (Camera Flare) = 0.58

For N+1
1.05 / 1.80 - 0.30 = 0.70

For N-1
1.05 / 2.40 - 0.30 = 0.50

This is a simplified version as the general value of flare changes with the luminance range of the subject. It tends to buffer the degree of development.

 

[Old-N-Feeble]

My development times are based on densitometer readings. They are not based on what I believe.

I understand that. It's been a very long time since I've dealt with this. My point is just that (I'm guessing) for one person's methodology, the difference in development time (in percentage) to adjust for N- or N+ is (I'm guessing) about the same for most films/developers, provided the developer and/or dilution is consistent. In other words N+1 for Acros 100 in XTOL 1:1 might be +15 percent vs. the same combo developed normally... and N+1 for TMY2 in Rodinal 1:50 might then also be close to the same +15 percent, all other handling techniques equal.

It might be +12 percent or +17 percent instead but then +15 percent would be pretty darned close (if I'm right).

 

[Stephen Benskin]

I understand that. It's been a very long time since I've dealt with this. My point is just that (I'm guessing) for one person's methodology, the difference in development time (in percentage) to adjust for N- or N+ is (I'm guessing) about the same for most films/developers, provided the developer and/or dilution is consistent. In other words N+1 for Acros 100 in XTOL 1:1 might be +15 percent vs. the same combo developed normally... and N+1 for TMY2 in Rodinal 1:50 might then also be close to the same +15 percent, all other handling techniques equal.

It might be +12 percent or +17 percent instead but then +15 percent would be pretty darned close (if I'm right).

Please refer to post #14. The bottom is minutes. There are six films processed in the same developer. The horizontal line at 0.58 represents normal development. All of them cross the line at different points. The slope of each curve represents how responsive it is to development. The steeper the curve, the more responsive and visa-versa.

 

[RalphLambrecht]

So if you want to apply N+1 to bring the luminance range up to 7 stops, how much extra development time would you give it

that answer is the result of a personalfilm-development test.

 

[Old-N-Feeble]

I've forgotten so much and it's getting worse. I won't confuse the issue any more.

 

[RobC]

It's not confusing, N+1 is a one zone expansion, and N-1 is a one Zone contraction. Which zone you choose, Zone VI, VII, or VIII is not that important. I follow Oliver Gaglianni's methodology as he taught it and he was one of Adam's pupils in the California School of Fine Arts (Photography) in the 1940's (see The Moment of Seeing, Minor White at the California School of Fine Arts by Stephanie Comer & Deborah Klochko, page 29).

Oliver used Zone VII because there is very little textural information in Zones VIII & Zone IX and None in Zone X. Fred Picker was also one of Oliver's students and he tried to simply it in his Zone VI Workshop since most photographers will never spend the time required to do the testing required to actually determine developing times for the different film/developer combinations, much less times for expansions and contractions.

It is confusing because no one ever really knows what someone else is saying unless they are very detailed in saying what they actually mean. For example, according to Adams, N+1 leaves zone IV on zone IV, so using your interpretation then zone IV would become zone V. And since everyones interpreation is different, discussion about the zone system becomes a very big circle of confusion.