Selecting a Paper for Zone Calibrations?

[cheekygeek]

I do not yet have a thorough understanding of the Zone System (working on "The Practical Zone System" as it applies to both film and digital) so I hope I'm not thread-jacking or muddying the waters but...

It seems to me that the process is nothing BUT variables. You don't take the manufacturer's ISO rating, but you do take a "standard" developer/time combination to run your initial tests to determine the ISO for your particular equipment/meter. I guess I don't understand why that particular variable gets arbitrarily nailed down.

As you can see, I've never been shy about running my ignorance up a flagpole if the end result will be learning something.

[Bill Burk]

Here's a quote from Minor White...

"In photography the testing is done to interlock the variables of camera, enlarger, one's pet brand of film ... and paper, combined with the respective developers, and one's personal processing habits".

One of the main outcomes of doing the testing is learning something.

It's better, scientifically, to isolate variables.

[Oren Grad]

It seems to me that the process is nothing BUT variables. You don't take the manufacturer's ISO rating, but you do take a "standard" developer/time combination to run your initial tests to determine the ISO for your particular equipment/meter. I guess I don't understand why that particular variable gets arbitrarily nailed down.

You have to start somewhere. But there's no reason you have to limit yourself to a single developer/time combination. It's just a matter of how hard you're willing to work, and how comfortable you are keeping different variables straight and assimilating a lot of information at once.

When I first did systematic film testing many years ago - with 35mm TX, as it happens - I shot three identical rolls of film, with each roll having a series of exposure bracket sequences. I developed the three rolls in D-76 1+1 for different times, one as recommended by Kodak, one shorter, and one longer. I printed a bunch of the frames on my then-standard paper. I learned a whole lot in a hurry.

[Leigh]

Usually, I purchase 25 sheets of Gallerie 8x10 Grade 3 FB paper on which to base these film calibrations. I don’t print on this paper, I merely use it for testing.

Forgive the observation, but I think you mis-understand the zone system.

You start with the paper you intend to use, then calibrate it against a step wedge to see how it responds to different negative densities.

Whether it's graded or VC you can do the calibration for different grades. You just have more options (i.e. half steps) with VC than with graded.

Then you work backwards to determine the film exposure and development to produce the negative densities you want.

When you do the calibrations in this order it's really quite a simple system.

- Leigh

[jeroldharter]

Use the paper you intend to print on, at the filtration you'd like to use as your standard.

Read Phil Davis's "Beyond the Zone System" if you'd like to understand why, or if you want a discussion of calibration that takes full account of paper as well as film characteristics.

Ditto.

[Bill Burk]

I think Neil figured it out a while ago, but was trying to see if he should use a fixed grade paper because it is single grade - something rock solid to calibrate to. [I happen to calibrate to graded Galerie because that's my favorite paper].

cheekygeek it sounds like you're just getting started.

As I reconcile the differences in my mind between sensitometry and Zone System, one reason the Zone System messes with the box speed is that you don't use the statistically average 6 2/3 stop subject brightness range at the heart. Zone System arbitrarily made the normal 7 (or 8) whole stops depending what reference guide you follow, so you could use the familiar roman numerals.

So you start out with a test that has wider range than ISO and try to fit it on the same paper from almost black to almost white, you are going to have to underdevelop a bit to get to what you just defined as "normal" into the same places. That is why I think you have to reduce your film speed a little bit.

There's flare included in Zone System tests too, if you do them on camera, so that messes with things too.

[Kevin J. Kolosky]

lots of good answers but some a bit too complicated for guys just starting out.

YOu don't need a step wedge.

What you want to do is pick a paper that you want to print on. And you already know what the range of that paper is. it can't get any whiter than it already is, and it can't get any blacker than black.

So take a blank film and develop it for the recommended time. And then print it for the shortest time it takes to get pure black. Now you have black.

Next, take a film and shoot something black in shade. Place it on zone 1 using the recommended ASA. Develop it for the recommended time. Print it same as the clear film. You want this print to be just a bit lighter than pure black. If not, change the ASA up or down til you get it.

Then, take your film and shoot something white in the sun, using the ASA you found for that Zone 1 negative. process it the same way as the zone 1 neg. If its the exact same as the paper you want to make the neg a bit less dense (let more light through) to get just a faint hint of very very slight gray. If its quite gray you want to make the neg a bit more dense (less light through) to get the print a bit whiter. You do that by changing your developing time.

Now you know what ASA to use and how much to develop for the paper your using to get black, white, and everyting in between.

[Bill Burk]

Minor White described a two-tone target - half sheet of plywood painted medium gray. The other half a full stop darker.

Now shooting that target you test for speed by placing exposures for the two sides on Zone 0 and I at different EI and finding the shot that prints pure black on one side and barely visibly lighter on the lighter side.

You test for developing kind of the same way - you meter and place the exposures of the two sides on Zone VIII and IX and find the development time that makes one side pure white and the other almost white. There's a little more to it but basically it's that simple and no equipment required.

[cheekygeek]

Minor White described a two-tone target - half sheet of plywood painted medium gray. The other half a full stop darker.

I'm off to Sherwin Williams to buy a quart of "Zone V" and "Zone VI". Do I want semi-gloss or matte?

[tlitody]

Neil,
I have done testing of this some years ago. The short answer is you test on the paper you will print on. And you use ZERO filtration. i.e. you test it as though it is graded paper. It is really that simple. Then you get your stouffer step wedge and produce a print using zero filtration and then some prints around filtration G2 to find what filtration actually corresponds to the papers natural contrast.
For MGIV FB I found the paper is naturally a G2 and on my enlarger (Durst L1200) the ilford given Y+M figures are spot on. i.e. what ilford say I should be using is correct for my durst. But I know they are not as accurate for all makes of enlarger and filtration which is why you should do the comparative step wedge tests.

Importatntly you should use fresh (new) paper and not older stuff that has been setting around for a few months. It can make a big difference and I have verified this by testing older papers.
The important thing to know is the MGIV FB with zero filtration gives grade 2. I used liquid dektol which is actually polymax developer. (i.e. not the one mixed from powder).

If you do your calibration this way then you will get negatives which you can print easily on both MGIV FB and Galerie.