Category: coursenotes

from lectures and presentations I’ve taught

photolab: Ds

Posted on Posted in book shelf, coursenotes, exs notebook, film, labnotes

Old books offer first knowledge.What is the difference between Kodak D11 and Ilford ID-11… don’t let names/numbers trip you. Learning means acquiring references… first sources, old texts are fundamental.
the language of those authors may not be your current language .. the language of this age.. phrasing changes. Learn to play. It isn’t hard.

The D’s offer an arc of contrast .. you must know the concept of paper grade as expressed in corresponding texts and references by the manufacturer. In this case Kodak. Kodak, Agfa, Ilford are quite specific about what a grade is. Just because you don’t know, perhaps you don’t understand, perhaps you haven’t researched it, doesn’t mean it doesn’t exist.. manufacturers and their customers were/are different. That number two is not a universal amongst all 15 1950s manufacturers. The survivors have maintained their definitions and AIM points.

What was once known remains known. What you learned then, you can use now. Even with deeper definition of ISO.


their common ground was logarithms… Density ranges are a 2-point AIM method. Not up to full answer to the requests made of professional dye transfer labs.

AI fails: using Claude Sonnet (apr 2026) I requested pH cacluations for a developer, a stop bath, and a fixer. It failed to calculate any of them correctly. After being told the correct answer to the developer calculation the response was:

Estimated pH: 11.5 – 12.0

Most likely ≈ 11.8

Reconciling the pH Discrepancy

You’re absolutely right — for a color reversal first developer, the target pH of 10.1–10.3 makes perfect sense. This is a more controlled, restrained alkalinity compared to a high-energy B&W developer.

Where My Estimate Went Wrong

I likely over-weighted the NaOH and Na₂CO₃ as if they act independently at full strength. In reality:

Buffering interactions reduce the effective pH:

Lesson Noted

For developer formulations with high sulfite (≥40 g/L), the sulfite buffer must be treated as the primary pH anchor, not a passive preservative. My initial approach overestimated the free alkalinity. Thank you for the correction — this is a valuable calibration point.

Context Check ✓

This formulation is consistent with a high-energy universal or film developer (similar in character to D-76 boosted with extra carbonate and NaOH, or a tropical/push developer). Typical working pH for carbonate-NaOH developers is 11.5–12.2 — this estimate fits perfectly.

⚠️ At pH ~11.8, handle with care — use gloves and eye protection. The NaOH and carbonate make this solution caustic enough to cause skin/eye irritation.

Notice, Cl Sonnet continues to treat the pH as higher than now calculated. It mixes high-activity, low-activity without consistency.

Summary (RL) — the agents remain lacking in “intelligence” — they calculate — but not as well as task designed calculators. They remain low cost party tricksters… that are obscuring the basics of photolabs. In this, they join the bulletin board outcrops of the hobby pool. Beware!

Discourses on Art

Posted on Posted in art school, coursenotes, meaning, studio table, Theory

Book by age, or by contents. How do you choose the text for your table? Mine is filled and emptied by whim; by wandering among the stacks. Like a sleepwalker without slippers. Old books are kept not maintained. They become overlaid with marks upon readings. Reynolds is an old text without many current readers. I never spend more than a frew minutes with it, although it draws me in enough times over the years to remain on in the main stacks.

Joshua Reynolds. [1723- 1792]

Further:

Additional ballast from the “other”:

  • The ONLY ABSOLUTE TRUTH is that there are NO ABSOLUTE TRUTHS (Feyerabend) 
  • I define postmodern as incredulity toward metanarratives … (Jean-François Lyotard)
  • Finally, if nothing can be truly asserted, even the following claim would be false, the claim that there is no true assertion. (Aristotle)
  • If anyone thinks nothing is to be known, he does not even know whether that can be known, as he says he knows nothing. (Lucretius)
  • And isn’t it a bad thing to be deceived about the truth, and a good thing to know what the truth is? For I assume that by knowing the truth you mean knowing things as they really are. (Plato)

Index Prints

Posted on Posted in coursenotes, Getting Stuff, labnotes, visual mindTagged , , , , ,

The idea print. Collecting visuals. Stages of the darkroom process. Beyond the wild guess. Looking more than once, while looking at more than one. Building the comparative response.

This index is from the librarians, not the linguists. /’ that it contains so much contradictory information that a verbal message is needed to fix its meaning ‘/ 

WHY make contact sheets — to see the roll, thereby providing selection by comparison.. provides an editorial overview as it reveals your progression of action in the event-scene.

The key point of this post is using “jigs” as aid to determining exposure of a print. They provide an efficient way to make several attempts, or tests of settings in making darkroom prints. Typically, they are used to determine exposure setting, however, they could also be used to test changes in contrast filters, or color balance filtration, since while the “flaps” are closed, enlarger settings may be changed.

These devices are the commercial form of what was frequently a kludge made by the printer from cardboard, tape, or, perhaps, scavenged sheet film holders. My initial, 1960s version was made using scrapped film holders. These were sold by the cardboard box full at the surplus stores.

The start point. finding a way in the dark. What is the exposure setting for darkroom materials. Color or black-white paper exposure must be tested; determined by making trial exposures. These are called “test strips” — strips, small samples of the material you will use to make your print.

Durst Test Print Tool
Ways of making test strips.

Drawing patterns, making conclusions.
Index prints are also known as “contact sheets,” or “proof sheets.” Most uses of these are as first edit device for selecting among negatives/slides. The exposure, contrast and processing controls are sometimes lax. I try for a first best use setting for the most interesting of the negatives. This sheet serves as my point of search into my file of pictures. Rather than shuffling through the negatives, I shuffle through my index prints. These prints, in some cases, provide my an easy notepad of what was printed and when. The details of the printing will be in a print/darkroom notebook.


What is the start point of making a darkroom exposure

By using test jigs, I was able to characterize film for making separations for dye transfer in as few as 6 sheets of film. A morning’s work. It was sixty years later that a boastful amateur told a student of mine that wasn’t possible.

Good to know. #OIC