Recording a daylight exposure

Purpose

To leave one row a stranger could repeat the exposure from, and which a season of rows adds up into the two numbers nobody publishes for your material in your processing.

When to use it

Every exposure whose light source is the sun: the unfixed silver photogram and Assignment 1 in Part I, and every sheet exposed outdoors in Part VI and Part VII.

It does not compute the exposure — that is Part VI’s calculation — and it does not conduct the session, which is the outdoor exposure session.

Before you start

You should already have the computed time and its bracket, or the exposure series the material’s own page prescribes. Makers quote sunlight as a range, not a number — Jacquard one to thirty minutes for cyanotype, HARMAN one to two minutes in bright summer sunshine and six to ten dull or cloudy — so the row records a choice made inside a range and is worth nothing unless it says which.

In the bag: the printable exposure log or the same fields ruled into the notebook; a pencil, which marks a damp sheet where ink will not; the timer; the meter, if you use one; and the maker’s sheet whose edition you will name.

Level A on the classification rubric: nothing is weighed, dissolved or heated and there is no waste. The hazards of being outdoors belong to the session procedure, not to this one.

Procedure

Before the card comes off

1. Rule the row up now, before anything is loaded. Fields written after processing are a memoir, not a prediction, and a memoir cannot be plotted.
2. Write the identifier — the date and a sheet number, 2026-09-04/03 — and the same string in pencil on the sleeve or the back of the sheet. Never on the emulsion.
3. Write the material and the effective speed you computed at, not box speed. ILFORD state that paper ISO speeds are not film speeds, and give MULTIGRADE RC an equivalent film ISO of 3 to 6.
4. Write the camera configuration: plate identifier, measured focal distance in mm, and the effective aperture N. For a photogram there is no camera; leave these empty rather than inventing a value for them.
5. Write the light, and which of three kinds it is: a meter reading with its f-number, speed and mode; an illuminance in lux; or a named row of a published daylight table. Kodak’s is quoted for average front-lit subjects from two hours after sunrise to two hours before sunset, so log the clock time too and a reader can see whether you were inside its window.
6. Write the sky in the four fixed phrases — clear, no cloud; thin high cloud, sun visible; broken cloud, sun in and out; overcast, sun not visible — with the ultraviolet index if your service publishes one, and whether your own shadow is shorter or longer than you are. In Part I that is the whole light record, and it is repeatable, which is what matters.
7. Write the computed time before any correction, then the reciprocity correction and the sheet and edition it came from. ILFORD’s own note is that one second or less needs none.
8. Write the intention in a sentence or two, with the predicted rendering of anything that will move. Part VII assesses it, and it is only falsifiable if it is written first.

While it runs

9. Write the clock time at the start and at the stop, and from them the time actually given, in seconds. For a band series, write the cumulative time against each band.
10. Write the whole bracket you gave, not only the frame you expect to keep.
11. Log anything that changed during the exposure — cloud crossing, somebody walking through — as a fraction of the total, with the time.

After processing

12. Write the processing: developer, dilution, temperature in °C, time and agitation. ILFORD note that long exposures raise contrast and the development may have to be pulled for it, so exposure and development are two fields.
13. Judge the dry sheet against a printed grey scale and write one word — thin, right or dense — in the row and again on the sleeve.
14. Write where the shadows and the highlight sat, and what to change next time, with a number in it. “Start at 45 s” is a change; “expose longer” is not.
15. Write the reconciliation: clause by clause, which parts of the intention happened, and which prediction was wrong in the words you used before the exposure.
16. Copy the collation columns across — identifier, illuminance, N, computed time, time given, verdict — which is the table the portfolio review fits an effective speed and a reciprocity exponent to.

How you know it worked

• Every number was either measured or names the sheet, table or meter it came from.
• Everything but the after-processing fields was written before the card came off.
• Sleeve and row carry the same identifier, and nothing is written on the emulsion.
• Units are the fixed ones — mm, seconds, lux or EV, °C — so June and October plot on one pair of axes.
• Blanks are blank because the field did not apply, not because you were in a hurry.

If a step fails

Step 1, the sheet is already exposed and no row was ruled up. Do not reconstruct from memory. Record what is certain, mark the rest not recorded, and treat the sheet as a test strip, not a data point.

Step 4, the camera fields do not apply. Leave them empty. A contact-printed photogram has no plate, focal distance or aperture, and inventing one puts a false point on the plot.

Step 5, the only meter is a phone app. Record the app and its reading, marked as an app. Part VI treats the ratio between two app readings as usable and a single absolute value as a claim the app cannot support.

Step 6, no ultraviolet index is published for your area. Use the shadow rule, which ICNIRP give as the simple test for an index above 4, and write the verdict rather than a guessed number.

Step 7, no reciprocity correction is published for the material. None is, for paper used as a camera negative. Write none published, uncorrected, and record the wider bracket you gave.

Step 9, the timer was not started, or stopped before the card went back on. Take the difference from the clock, write it, and mark it estimated. An estimate you can see beats a number you will later believe.

Step 13, there is no printed grey scale to hand. Shade a strip of card in six steps and judge every sheet of the season against that same strip. A scale you keep beats a better one you replace.

Step 16, the log is lost. Rebuild the collation table from the sleeves: identifier and verdict were written on each one for exactly this case, and the rest follows from the identifier.

What to record

One row per sheet, on sheets EX-1 and EX-2 of the printable exposure log or the same fields ruled in the notebook — the first group closed before the exposure, the second filled in when the sheet is dry — then one line per sheet on the collation sheet, EX-3. Where the light changed mid-exposure the row carries two timestamps and a fraction, never an average.