"tonality" and "acutance"

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in conection with rodinal those two words are often mentioned. can anyone explain what is meant with that? does it mean, more shades of grey can be differentiated?

-- stefan randlkofer (geesbert@yahoo.com), March 04, 2002

Answers

Acutance is synonomous with sharpness- the way two areas of different densities on a negative meet to form a line- "hard" lines result from high acutance developers, indistinct lines is characteristic of poor acutance. Most high-actuance developers are described as grainy, but the sharpness makes up for this IMO. Many fine-grain developers suffer from poor acutance, IMO.

I'll let someone else tackle tonality.

-- Mike DeVoue (karma77@att.net), March 04, 2002.


Tonality (as well as acutance) is discussed in some depth in the "The Film Development Cookbook", by Anchell and Troop, Focal Press 1998. I would highly recommend this book, even if you have to sneak a peek at your local bookstore. It may also be available at your library. If you can afford to purchase it, I would do so.

-- Michael Feldman (mfeldman@qwest.net), March 04, 2002.

Tonality (gradation?) is what Rodinal hasn't got, IMHO. A smooth transition from one tone to another; many shades of gray.

-- Bob Fleischman (RFXMAIL@prodigy.net), March 04, 2002.

I agree, Rodinal, HC-110 and other accutance oriented developers tend to result in poor tonality in 35mm and perhaps 6x4.5 format. It's impractical to seek a developer that gives everything. People tend to overemphasize whatever they like. Be skeptical when you hear too good story like "exceptional accutance and very beautiful tonality." (Then give me a bad developer! :-)

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), March 05, 2002.

Rodinal renders a very special tonlity of antique look. I think using a larger format is a must with Rodinal. Use a slow non-T grain film (Verichrome is great with Rodinal, APX, FP4, PanF plus). It's true that there is some kind constriction in tonality with Rodinal esp. with shadow and midtones, but highlight offer very smooth and beautiful gradation. Overexpose by 1/2-1 F-stop. It's graet with portraiture but not other kind of photography.

The issue of tonality is very poorly discuused in any book you'd read. It's something that you have to find yourself.

Xosni

-- Xosni (xosni@gega.net), March 05, 2002.



I think different people mean different things by the word "tonality". When referring to a print, it is more clear that one speaks about the subtle colour of the grey tones that compose the image (warm, cold tonality). On the contrary, when talking about a negative, it is not really clear if someone is talking about the separation of different tonal values or the subtle contrast of the different parts of the image (maybe the highlight contrast ?) It is sure that since no "objective" or "agreed" definition has been established, a subjective opinion about whether this or that developer gives better tonality or not shall be given by every B+W fan. On the other hand, acutance is something we all understand easier and have more or less an objective definition for. So, we can say that the developers that favorise edge effects shall ameliorate the acutance of most films and those that are supposed to give finer grain shall, in general, make it worse. Rodinal does not have a grain shrinking effect, so it shall give good results on the acutance part of the story, especially if used in such dilutions that compensation effects (edge effects) will take place.

-- George Papantoniou (papanton@hol.gr), March 05, 2002.

I'm glad to see that everyone is as confused as I am. Tonality seems to imply lots of rich shades of gray. IMHO, that has more to do with lighting and subject than anything. All normally processed films and developers will produce a complete palette of grays from black to white. So what shade of gray is Rodinal incapable of producing? Yet tonality is real- I know it when I see it, and it took me near forever to come up with a film/developer combination that produces it more often than not. Hint- it wasn't Rodinal. If anyone has a clear definition of tonality that also holds up in sensitometric terms, I'd like to hear it, as most books treat it poorly if at all!

-- Conrad Hoffman (choffman@rpa.net), March 05, 2002.

"All normally processed films and developers will produce a complete palette of grays from black to white." (Conrad)

Well, if you process 35mm HP5+ in Rodinal and blow up to 11x14 or larger (not recommended :-), then you see black and white, not a complete palette of greys.

When you talk about sensitometric characteristics, you are talking about average of certain large areas. On the other hand, RMS grain measures fluctuation in averages of small areas. Accutance has to do with more locally transitional aspects, while tonality has to do with overall effects of all these characteristics.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), March 05, 2002.


RE RYUJI COMMENT: It is simply false that An excellent print cannot be obtained from printing HP5+ developed in Rodinal. That was my film developer combination for 10 years and produced outstanding results with HP5+ rated at EI200 and developed at 1:25 or 1:50. Great Negs and great prints printed on coldlight. Can see grain, but so what. Prints were,are beautiful!

-- John Elder (celder2162@aol.com), March 05, 2002.

Forgot to say the film was 35mm!

-- John Elder (celder2162@aol.com), March 05, 2002.


Well, yes, but... fine grain doesn't seem to guarantee tonality. I've made some pretty horendous negs with TMX, yet some very nice ones with the same stuff developed in Rodinal (that had obvious grain). I've had good tonality with Tri-X and HP5, too. So I still know it when I see it, but can't define it!

-- Conrad Hoffman (choffman@rpa.net), March 05, 2002.

so conrad, don't hold back! what is your film/developer combo that made the race?

-- stefan randlkofer (geesbert@yahoo.com), March 05, 2002.

I agree - tonality is used in some pretty confusing ways. The way I think of this is that acutance is contrast in small areas of the negative and provides an impression of sharpness (i.e., how sharp is the edge in small details that cannot be measured with a spotmeter, for e.g.). I think of tonality as the shape of the characteristic curve (contrast in big areas that can be measured with a spotmeter, for e.g.) which determines what kinds of greys you will get from different parts of the scene.

Small changes in curve shape can make appreciable differences in the print. You can keep the same area of the subject as white and black in both developers, but if the curve shape is different, the midtones will be rendered in very different ways by the two developers. Many compensating developers, for e.g., provide added shadow and midtone contrast at the expense of highlight contrast.

Cheers, DJ.

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), March 05, 2002.


Accutance has always been a subjective issue in photography (One persons "sharpness" is anothers "softness" so to speak.) and more than film / developer combinations come into play when considering how "sharp" an image appears to the eye. There is also the optics of the camera and the enlarger, as well as the resolution of the paper and the contrast selected. As an aside question that was raised here and in many previous posts that touch upon these subjects - Why is it so readily assumed that printing larger than 11X14 from a 35MM neg is less than desirable?

-- James Megargee (jmegargee@nyc.rr.com), March 05, 2002.

Stefan, the magic formula is only magic if you live in my gray climate, shoot the kinds of things I shoot at the focal lengths I prefer, agitate the way I do, have my particular condenser enlarger, prefer my favorite paper, and most important, like the same tonal qualities! My point is that if it were so easy, we'd have all settled on the same combination years ago and not even be having this discussion. I wasted a decade fooling with TMX, yet others can get beautiful results from it. Same thing for lots of combinations. Anyway, my joy comes from 35mm FP4+ at an EI of 64 for 9 minutes in FX-2 at 68F. Gentle agitation at one minute intervals, and printed on Ilford Cooltone RC. Grain is extremely fine and unobtrusive, sharpness is high, and highlights stay under control. YMMV... alot!

-- Conrad Hoffman (choffman@rpa.net), March 05, 2002.


yeah, um, hmmm. Some interesting answers but to answer the question, I think DJ is on the right track, ie the only track. Tonality in general isnt something thats present or lacking, or desireable or undesireable , its a subjective quality (though quantifiable but thats boring) thats always present in some form.

I was hoping some more specific comments on Rodinal tonality would come out of this, as I've just tried it recently (on FP4+) and got a "different" tonality but havent used it enough to describe it well

-- Wayne (wsteffen@skypoint.com), March 05, 2002.


"It is simply false that An excellent print cannot be obtained from printing HP5+ developed in Rodinal." (John Elder)

I didn't say that. I just said you don't get a complete palette of greys and from tonality point I don't recommend to make a large magnification of the neg made that way. Really good 11x14 prints from 35mm neg is challanging especially if you work with fast films processed in Rodinal.

"I think of tonality as the shape of the characteristic curve (contrast in big areas that can be measured with a spotmeter, for e.g.) which determines what kinds of greys you will get from different parts of the scene." (N Dhananjay)

If identical shape of the exposure-density curve can be obtained from two film-developer combinations, do you think the tonality will be identical?

If that question is too hypothetical, then what about if 5x7 and 8x10 prints are made from the same frame of 35mm neg of HP5+ in Rodinal 1+49 and viewed from appropriate distances? Do you consider them to have identical tonality? (assume you can adjust whatever you can in the printing stage with common darkroom techniques)

In my view exposure-density curve is a radically simplified characterization of the film-developer combination disregarding all local properties of the resulting images. Tonality is also affected by more local image qualities including apparent grain and smoothness or "coherence" of each grey level.

It is unrealistic to think a minuscule difference in the curve significantly affects overall tonality, especially because our eyes' ability to discriminate grey levels becomes very poor as the distance separating two grey panels (presented as comparison stimuli) increases. It also becomes poor as the grey panels become smaller. Exposure-density curves are useful measurements, but they cannot predict tonality or many other image qualities by themselves.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), March 06, 2002.


That's reasonable, but I still think the original scene has an awful lot to do with it. When I see lots of graduated areas of midtone I think "tonality". Modeling. Flat slabs of gray don't do it for me. This morning I was out walking the dog in the fresh snow and realized that the snow didn't have any visible detail at all. Gray sky, gray snow, but no modeling or texture. A photo would have been slabs of gray, and no film or developer or large format would have improved it. Actually, grain might have been desirable to add some interest. If the details with modeling are small, say tree branches and sunlight, and the modeling is obscured by excessive contrast, grain, or edge effects (see, Rodinal at least got mentioned!), then what I consider tonality, suffers. So, for me, tonality is lots of smooth modeling in the midtones; grain and sharpness have to be good enough not to obscure it, and that depends on the subject.

-- Conrad Hoffman (choffman@rpa.net), March 06, 2002.

Ryuji What you said was"Well, if you process 35mm HP5+ in Rodinal and blow it up to 11x14 or larger{not recommended}then you see BLACK AND WHITE, not a complete palette of greys" To me that means you can't get an excellent 11x14 print from HP5+ developed in Rodinal. I beleive this to be a MOST logical deduction from your above statement. AND you are wrong. I have been printing full frame 35mm Hp5+ 8x12 and 12x18 for 10 years with great success!

-- John Elder (celder2162@aol.com), March 06, 2002.

Of course the developer was RODINAL!

-- John Elder (celder2162@aol.com), March 06, 2002.

>>> If identical shape of the exposure-density curve can be obtained from two film-developer combinations, do you think the tonality will be identical?

I'll hedge (and if pressed, say no)....see below.

Let me clarify. I completely agree with you that a characteristic curve does not capture all that there is with regards to film- developer interactions and responses (e.g., edge effects etc). One of the most exasperating things is that there is nothing in our vocabulary to help us discuss how micro-contrast and macro-contrast interact. And for good reason. As Conrad points out, these things are hugely reliant on individual scenes and subjects to begin with. But one of the other problems is that we use terms rather loosely without specifying what we mean by them. For example, what you seem to be referring to when talking about tonality, I've heard other people use the term gradation for. I was merely pointing out that tonality is used in different ways. As long as one is aware that there are issues of macro contrast (which I think is captured by the characteristic curve) and micro contrast (contrast in small areas, which could presumably be captured by microdensitometer traces but is hugely reliant on inherent subject contrast to begin with) and these interact to produce the 'look' of a film-developer combination, one has a subjective understanding of tonality/gradation/whatever one wants to call it. Cheers, DJ.

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), March 06, 2002.


To: John Elder. You are simply making a straw man to beat based on your interpretation. I will not follow it any farther.

To: DJ. When you discuss some property of the film-developer combination, don't you hold lighting condition fixed while you vary film and/or developer? It is true there is a lot to do with lighting and subjective judgement in real images, but that's not what we are concerned about when we discuss tonality and accutance of film-developer combinations.

The following is bit off topic.

"One of the most exasperating things is that there is nothing in our vocabulary to help us discuss how micro-contrast and macro-contrast interact." (N Dhananjay) Well, it's not that exasperating. There are other things that we know have to do with each other but the relation is poorly understood. For example, some argue photographic lens design, in-focus and out-of-focus image qualities, which are quite well understood in terms of optics, but many photographic optics users do not care about it and not well understood by those the users. There are many things we can't discuss quantitatively, but a large part of it is due to lack of our understanding of how we perceive such visual (or other forms of) stimuli.

You ask wine tasters: "what does integration mean?" "what is good finish like?" "waht's the difference between depth and complexity?" and you will hear similar kind of discussions, if not worse. (though this doesn't justify we stay happy with what we know now)

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), March 06, 2002.


>>> To: DJ. When you discuss some property of the film-developer combination, don't you hold lighting condition fixed while you vary film and/or developer? It is true there is a lot to do with lighting and subjective judgement in real images, but that's not what we are concerned about when we discuss tonality and accutance of film- developer combinations.

But isn't that the problem - that all of these variables including type of subject interact in sometimes pretty complicated ways? After all, one scene (let's say something with plenty of local contrast but also smooth greys e.g., skies) provides the best 'tonality' in D23 while another scene (say limited local contrast especially in highlights e.g., snow and ice patterns under uniform light) provides the best 'tonality' in pyro.

I agree that there may not be a solution - we're apparently talking about something that everyone recognizes when s/he sees it but can't put down in measurable ways and that's fine - this is an art form we're talking about, not paint-by-numbers. I'm merely saying that I think clarity in terminology is a good idea because it helps. If nothing else, it makes communication a little easier and there are clear grounds for agreeing to disagree. One isn't guessing what someone means. Some terms have a common shared vocabulary/meaning, some terms deal with subjective areas that requires personal experience to make judgments. But one is clear about which term is which. Cheers, DJ.

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), March 06, 2002.


To : everyone

Good discussion, guys, some really interesting things have been written, but don't try to end up to a conclusion, you won't get to it. Some things you are talking about are just not understood in the same way by different people...

-- George Papantoniou (papanton@hol.gr), March 10, 2002.


Saint Ansel clearly indicates in his book "The Negative" that sharpness (actuance) should never be compromised regardless of grain size. I've started using Rodinal with my 6x4.5 and have had excellent results, I look forward to trying it with APX100 in 4x5. I propose this: Rent, buy, or borrow a 4x5 or 8x10 camera, shoot your favorite film and develope it in your favorite developer, use that photograph as your benchmark, you'll see micro-macro gradiations, tonality, and anything else you care to describe. It's simple folks- there's no substitute for square inches....

-- Albert Martinez (albertjmartinez@yahoo.com), April 24, 2002.

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