Kerik does not own a densitometer, and he makes wonderful prints. Don't get something like that just because a propellerhead like me starts talking numbers. The only reason I throw those numbers around is because of a sick fascination with the quantitative that dates back to childhood. They just provide a quantitative shorthand do describe something that your eyes and the meat computer in your head is just about as good at recognizing.
As far as infinite range of tones being a definition of tonal range, no, my point is that any analog process or any paper can give you an infinite range of tones. I think when most people use the phrase tonal range, they mean 'the difference between black and white' . But again, it is an imprecise term, and is being used when there are some accepted unambiguous terms around that describe what I think people are attempting to describe. Density Range [the transmission density difference between the shadow and highlight on a negative), Exposure Scale( the difference in LogD exposure required to make a print from pure white to pure black) are two such terms. They have precise meanings. Tonal range has about as much precision as me telling my spouse that her dress looks 'nice'. BTW, i learned long ago that line is not recommended.
Anyway, what I'm saying is don't get balled up in all the arcana here. Find what you like in a print and learn how to get what you like. The number stuff may help you if you are so inclined, but if you're not, just practice, practice, practice.
Hey Aggie, don't worry about it. Lots of us don't have a densitometer. We do have eyes and we do know what we like when we see it (usually). What the guys are saying in a nutshell is that doing something a different way will give you a different look. Sometimes subtle, sometimes not. Look at the work of other people, good and bad. Decide for yourself what it is you like or don't like. Occasionally copy what they do and how they do it, it is a great learning tool. Make mistakes. Some people get all involved with measurements and numbers. They are looking for ways to get a handle on things so they can predict the results and decide how to get there. Many of them are established pros who just can't afford to waste time and materials. They need some way to get consistently excellent results every time, often under horrible conditions, a fixed budget, and within ridiculously short deadlines. Sometimes numbers are just a way to pin down something you already can see, or already "know" but can't quite put your finger on. Do like I do. Let them do all the research, and then take what you want from it. My best advice at least in the beginning, is to keep it simple. Pick a film you like, for whatever reason. Get to know that film, what it can or can't do. Do the same for developers and papers if you are into printing. Once you are comfortable with that, then branch out.
Aggie, the numbers are just to illustrate a point. Actually if anything I am more on your camp after having done all that sensitometric rigamarole. When I first started , like many I wanted to make pictures like Ansel Adams, and I thought a thorough understanding of sensitometry was required. So I did all that, and I learned a lot, but now I am back to developing by inspection, etc. The one advantage of having learned all that was that I know what a good negative should look like, and how to obtain it, but it is not necessary to make great prints. As far as I know Edward Weston never came withing 100 feet of a densitometer.
If you learn sensitometry you have a greater control over your materials, which I think makes expressing your "idea" or vision easier, but by no means it is essential, I think Michael Smith does his contrast developing by the "glug, glug" method...http://apug.org/forum/html/emoticons/tongue.gif. he adds more activator to the ABC formula as he thinks is fit, he does not do all the sensitometry.....of course with his experience he has probably made all the mistakes there is to make and knows what to do by intuition.
So dont get bog down on the numbers, is like the coffe cup holder in your car, is nice to have but not essential to the operation of the car.
Using a densitometer is just a more precise way of getting from A to B. There is nothing magical about it. You are basically qauntifying the characteristics of paper and film and how they relate to each other and specific chemistry. As Steve and Clay point out is not required to make beautiful prints. You can get perfectly good info by making tests of film through exposure and developing times in different developers and keeping a notebook of results. A good methodical approach to testing materials will give you just as good a result and allow you to make determinations in the field about how an image will look based on those tests. If you are not testing now, there are several books and sources on the web for materials testing protocols.
The other option is to stick with one film and and developer combination and learn all of its subtleties and characteristics. One photographer who comes to mind in this regard is Ralph Gibson. For years his only film was TriX souped in Rodinal. Yet the range of print characteristics he can produce with this one combination are incredible.
I have borrowed a densitometer a couple of times just to understand how it is used and what it can do for me. I appreciate it as a precision tool that provides certain results, but I just like to do things the hard way sometimes.
I've owned a densitometer, and I agree that it's useful to use one for a while, particularly if you are trying to learn from books and don't have access to galleries of fine prints. If you take classes with a teacher who is really competent and can show you what a good negative looks like and how to get a good print visually, that's a perfectly good approach as well. Part of the reason that the Adams books have been so successful, I think, is that objective readings from a densitometer can give you an idea of what you're aiming for, which reproductions from books alone can't really do.
with regular developers you can nail film speed and developing times in the same day. I used to have one that the company I used to work for issued me. Damned handy. I have one for film built in to my Metrolux II but I have to find the instructions to use it. They are not much use with ABC or PMK . I don't have a blue channel which I think I remember you will need to read negs with stain.
I've got a black and white unit and I only used it to establish film speeds and development time when I got into sheet film (TriX and HC110 per St. Ansel) some years ago. I didn't use it again until I started doing unsharp and sharp masking. I didn't use it at all to determine my rating of Bergger BPF 200 or the use of ABC pyro. I spend my time making photographs today. Testing can be a all consuming affair.
I agree. Its easy to enough to test while you're working. If you keep some simple notes, it will be easy to decide "Hey next time, I'll add 1/2 a stop of exposure and develop another 2 minutes, and I'll bet I'll be right on" I've always been amazed at the number of posts that you see on ph***.net that ask questions like "My negatives are thin and low contrast, what do I do?" Doh! Expose a little more and develop a little more.
The only time you need to be a little quantitatively obsessive is if you are doing some process that has no contrast control in the printing, and demands a negative of a particular density range. I've found argyrotype and VDB to be sort of unforgiving in this way. But the easy way is just to stick to processes that give you some ability to compensate for variations in the negative's density range: variable contrast silver gelatin, platinum/palladium, and maybe gum. If your time is short, and you're not shooting for a client, just take pictures and learn from them, and modify things as you go. Or take advantage of other's work, as has been mentioned previously.
I hate testing!
When I first started LF photography and wanted to learn the zone system, I went out and took god knows how many photos of the white house next door. I hated it. It made me not want to use a camera again.
I was hesitant about testing-as-I-go, thinking that I would make a bad exposure of the perfect scene, of screw up the development of the perfect exposure, etc. But so far, so good.
I have never even seen a densitometer, but I am interested in learning what the 1.- numbers mean when I read an article like the one Ed Buffaloe posted. Is there a source that explains the densitometer readings in a way that I could translate to zones or tones or something more practical for me?
Hahaha good one! I hated the "Zonies" too for a long time. After many months of poring over the claims and methods of various people, and re-checking their math I was finding only contradictions and double talk. So and so would say he rated and exposed for this long and developed for that long to expand for N+whatever. Then he rated and exposed for this long and developed for that long to contract for N-whatever. There was a sense that if I didn't follow all this exactly, life would end as we know it. Guess what? The numbers never added up! I crunched the numbers exactly as stated, and came up with the realization that both negatives should be exactly alike. I finally broke down and went to the source, The Negative by AA. How wonderfully simple he made it seem. Expose for shadows, develop for highlights. Overexposure is a better mistake than underexposure because a dense negative will have "data" you have a chance of recovering and a blank negative will have nothing to "save". Pick a paper or contrast filter to match the negative. Dodge and burn because even good negatives will have spots the need some "fixing". All simple common sense. Now I just shoot the darn thing and use a seat of the pants approach. Better that, than to be paralyzed by the horrible gnawing fear of making a mistake wink wink.