check batt day

One must from time to time attempt things that are beyond one’s capacity.”-Pierre-Auguste Renoir 

the first of the month; time to check electronics in the studio and the lab.

in or out? when you put the camera, meter, whatsit away, what is your cleanup and storage protocol? Perhaps you haven’t considered the question. When you’re done, do you leave stuff in the bag or on a shelf.

In my commercial world, the process of ending one thing was prep for the next.

In the age of the professional studio every assignment had a set up and a teardown time. cameras along with all equipment were cleaned at shoots end; repairs needed were noted.. before a shoot the equipment was checked; this included batteries for those portable electric items. items which were stored a long time while being assumed always at the ready were checked monthly; batteries being swapped out, freshly charged ones being put into service. For Equipment cage operations someone in charge of the cage followed the procedure with every equipment check-in and check-out. Schools of journalism instilled the discipline in their students which likely spread throughout that industry.

I keep batteries out of infrequently used darkroom equipment, but do keep batteries in the actively used cameras. Lightmeters are not stored more than a week with batteries enclosed. When the meter is being stored, it is stored with its battery put into a bag-box with a tag marked with dates. If the meter is going out pn location it is tested with vtvm. Field kits always include tested spares.

Equipment Poor:

It is also a time to prune, to dead-head equipment. If it isn’t being used, since I’m not a collector, and it is a dust collector, I consider passing it along. 

Emergency in the gun-belt states. Most of the US experiences competitive power failures. So the Free Markup has devised the house-batt. I keep batteries in flashlights; along side these are 8-hour candles. And so it goes.

There remains the ground of difference between being awake and being aware

photolab: Ds

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!

scraps :: techday may 2

snippets from other posted notes. Techdays are fewer, since not much is newer in this my interest-age.

one way of checking your understanding of the past. dye transfer vs type c (aka, RA-4)

in some other post, I have more detailed costing. This was done at a lunch table a year ago; recently accessed while clearing a box of notes.

No idea why I kept it. Had no other info… no phone, nothin…

putting this together so you have something to start with. Spending time finding good sources is worhwhile at initial stages.

old world prices… when they started

from two years ago Ilford’s request for interest in a new sheet film