Night exposure session

Purpose

To make one exposure after dark and come home with three things: the sheet, a log entry that makes the exposure repeatable, and yourself.

When to use it

Every exposure whose light is not the sun — Part VII’s night assignment, the traffic and moving-light work in time in the frame, and any twilight sequence that finishes in the dark. It runs from the leave time being written down to your saying you are home.

It does not compute the exposure — Part VI does — and it does not cover a camera left in place for weeks, which is the night assignment’s own solargraph stage. In daylight, use the outdoor session instead; indoors afterwards, film processing takes over.

Before you start

You should already have the corrected time computed, with the reciprocity exponent, its source and the band it carries written down, and the backs loaded by loading a pinhole back. ILFORD are explicit that at very low light levels other variables enter and some trial and error may be required, so carry a bracket rather than a single number.

Level A on the classification rubric: nothing on site is weighed, dissolved or heated, and the trays are indoors afterwards. The hazards are traffic, the ground in the dark, and the cold.

Worn: a reflective or light-coloured outer layer, which is the protective equipment here in the way gloves are in the darkroom, over warm layers. Packed: a torch and a second light source, a charged phone, a stable tripod, an hour-long timer, a changing bag if you load on site, notebook and pencil, and the meter.

Procedure

Before you leave

1. Write the leave time in the log — the clock time you pack up regardless of how the work is going — and tell somebody the site, the route and that time.
2. Choose a site you have visited and photographed in daylight. Going alone, choose somewhere overlooked rather than remote; prefer to go with somebody.
3. Ask permission in daylight for anything you will enter, stand on or attach to: private land, a yard, a roof, railings. Asking at midnight is not asking.
4. Compute the exposure at home and log the metered time, the exponent, its source and its uncertainty band before you go.
5. Load the backs at home, in the light the material needs, and count the sheets.
6. Dress, then check the torch, the spare and the phone charge.

On site

7. Arrive with light still in the sky. Place, level and frame the camera while you can see it, and write the framing down: everything after this is done in the dark on a camera you have already aimed.
8. Stand the tripod back from the kerb and from any edge, leaving a clear passing width: section 137(1) of the Highways Act 1980 makes wilful obstruction of a highway an offence in England and Wales, and a forty-minute exposure is forty minutes of tripod. Where there is no pavement, keep to the right-hand side so you can see oncoming traffic.
9. Meter, and log the reading with its clock time. Record the lamp type — sodium, metal halide, white LED — as an observation; it is not a correction this course can give you a number for.
10. Turn the torch off before the shutter opens, and leave it off. A torch is not a specified safelight: Kodak state that most papers keep some sensitivity to the colours even a recommended filter transmits, and that safelight exposure should always be minimised.
11. Open the shutter and write the start time down at once.
12. Stay with the camera for the whole exposure. Where you must load on site, use the changing bag with the torch off; a dim red torch used to find a holder points at the ground and never at the paper.
13. Meter again before you close, and log that reading with its own clock time.
14. Close the shutter, then stop the timer, in that order. Push the dark slide home before the back comes off.

Coming back

15. Sweep the site with the torch before you move: sheets, holders, dark slides, tape, timer, the camera’s own parts.
16. Leave at the time you set in step 1, and say you are back to the person you told.
17. Unload in the light you loaded in, and log the clock time each sheet reaches the developer. Kodak instruct that film be processed as soon as possible after exposure; Part IV’s latent-image lesson owns why, and on a night session the first sheet may wait three hours.
18. Process, or store the sheets light-tight and process at the first opportunity.

How you know it worked

• The two logged clock times differ by the exposure you meant to give.
• Every sheet carries a metered reading before and after, each timestamped, so the light reads as a rate of fall rather than one guess.
• Every log line names the exponent and where it came from, which is what makes the negative diagnosable three weeks later.
• The leave time in the log is the time you actually left.
• Sheets carried out equals sheets exposed plus sheets carried back, and nobody is waiting on a message you did not send.

If a step fails

Step 3, the owner cannot be reached. Move to a public site and work from the pavement. An unanswered request is not permission.

Step 7, you arrive after dark. Aim on a lit marker with the torch on the subject rather than through the camera, and treat the first sheet as a test rather than the picture.

Step 9, the meter reads below its range. Do not extrapolate the meter. Fit a larger hole, which changes the aperture without spending time you do not have, and bracket.

Step 10, headlights or another torch crossed the frame. Log the clock time and the direction; that band has a cause, and a named cause is not a mystery fault.

Step 11, the timer was not started. Do not estimate. Close the shutter and treat the sheet as a test strip.

Step 12, the site turns uncomfortable, or somebody objects. Close the shutter and go. Explain what you are doing if that settles it; the negative is repeatable and the evening is not.

Step 14, the timer stopped before the shutter closed. Take the extra seconds from the clock, add them, and mark the figure in the log as an estimate.

Step 16, the leave time falls in the middle of an exposure. Close the shutter at the leave time and log the time actually given. A part exposure you can read beats a full one you waited too long for.

Step 18, processing tonight is impossible. Store light-tight, log the interval, and expect a thinner negative than the same exposure developed at once.

What to record

One line per sheet on the exposure log: date; site, with bearing and what lights it; clock time at open and at close; the material and its batch; the hole fitted with its measured diameter; both meter readings with their timestamps; the lamp type; the metered time; the exponent, its source and its band; the corrected time actually given; anything that crossed the frame; and the interval from exposure to developer. Once per session, add the leave time, the person told, and whether the two matched.