Tidal Grain

A pinhole on the pier

2026-10-04T08:00:00Z

A pinhole camera is the cheapest long lens-less exposure there is: a body cap with a hole drilled through it, a square of brass shim taped behind, and a hole in the shim made with the tip of a needle. Nothing focuses, so nothing is ever out of focus; everything is equally, gently soft from the wet boards at your feet to the horizon.

How big a hole

There is a best diameter for every distance between hole and film. Too large and the image is a blur of overlapping discs; too small and diffraction smears it instead. The usual rule of thumb is 1.9 times the square root of the distance multiplied by the wavelength of light, which for green light gives the figures below.

Hole to film	Best hole	Works out to
25 mm	0.22 mm	f/112
50 mm	0.32 mm	f/159
75 mm	0.39 mm	f/194
100 mm	0.45 mm	f/224
150 mm	0.55 mm	f/275

A hole a tenth of a millimetre off is not worth a second attempt. A ragged hole is: sand the dimple flat with fine wet paper and look at it against a lamp through a loupe. It should be round and have no burr.

What the exposure is

Meter at f/16 and count stops. From f/16 to f/159 is a little over six and a half stops, so a metered 1/125 s becomes about three quarters of a second before the film's own reluctance is counted, and at those times it must be counted. On an overcast afternoon the metered 1/30 s at f/16 turns into three seconds on the dial and something like five on the film.

Pinhole, 6×6, fourteen seconds. Soft everywhere, sharp nowhere.

What goes wrong

Wind. A fourteen-second exposure on a pier that hums under every wave is a recording of the pier. Hang the bag from the tripod and stand upwind.
Flare. There is no lens hood because there is no lens. Keep the sun behind a post, or accept the star it draws.
Dust. At f/159 every speck on a digital sensor is in focus, which is one more reason to use film here.
Counting. A cable release with a lock and a watch with a second hand beat counting elephants in a cold wind.

The first roll is always for calibration. Bracket by a whole stop either side, write the times on the back of a hand, and read them against the negatives a day later.

A tide table is an exposure tool

2026-09-28T08:00:00Z

The picture planned at the kitchen table rarely survives the walk down, because the sea is not where it was the last time. A tide table costs nothing and removes most of the surprise. Read it the evening before, together with the time of sunset, and half the decisions about focal length and exposure time are already made.

Four states and what they give

State	What is there	What it suits
Low water	Wet sand, pools, the feet of the groynes	Reflections, texture, wide lenses close to the ground
Flood, first half	Water creeping over flat sand, slowly	Long exposures with a clear edge between wet and dry
High water	Posts and rocks half sunk, surf against the wall	Mist around solid shapes, 20 seconds and longer
Ebb, first half	Water draining through shingle and off the weed	Streaks: one to four seconds draws the lines

The middle two hours of a rising or falling tide move the most water. On a flat beach the edge can travel a metre in a minute, which is worth knowing with a tripod in it.

Groyne posts on the ebb. Delta 100, forty-five seconds at f/11.

The exposure follows the water

How long the shutter stays open is a decision about the sea's surface, not about light. Half a second keeps the shape of a wave. Two seconds draws its retreat as lines. Thirty seconds flattens everything into fog with the rocks standing in it, and four minutes makes a sheet of metal. Choose the surface first, then reach for whatever filter makes that time possible at an aperture the lens is good at.

A plan that fits on a card

Time of low and high water, and their heights. A spring tide uncovers ground that a neap tide never does.
Time of sunset and the end of civil twilight. The useful light lasts about forty minutes after the sun has gone.
Where the way out is when the water is up. Some coves have one, and it floods first.
Which way the wind blows the spray. Stand with it on your back, or wipe the filter before every frame.

None of this guarantees a picture. It does mean that the hour by the water is spent looking rather than waiting for the sea to arrive where you hoped it would be.

Yellow, orange, red: filters over grey water

2026-09-06T08:00:00Z

Black-and-white film sees blue more brightly than the eye does, which is why an unfiltered sky prints as blank paper. A coloured filter holds back the light of the opposite colour: yellow, orange and red all darken blue, each more than the last, and each takes more light to do it.

Filter	Factor	Open up by	Sky	Sea and haze
Yellow (K2, 8)	2×	1 stop	Close to how it looked	Slightly crisper distance
Deep yellow (15)	2.5×	1⅓ stops	Clouds stand out	Haze noticeably cut
Orange (21)	4×	2 stops	Dark, dramatic by evening	Blue water goes deep grey
Red (25)	8×	3 stops	Near black overhead	Horizon cut out of the haze
Green (11)	4×	2 stops	Mildly darker	Weed and wet rock lighten

The factors are the makers' and assume daylight. Towards dusk the light is already warm, a red filter passes more of it than the factor allows for, and the negative comes out heavier than planned. Half a stop less than the table says is a fair correction in the last hour.

Metering through the glass

A camera meter reading through a red filter usually underexposes by about a stop, because its cell does not see colour the way the film does. Meter without the filter, apply the factor by hand, and the negatives become consistent. With yellow the difference is too small to matter.

Wind from the west, eight minutes. Pan F Plus, red filter.

When a filter does nothing

A sky that is white with cloud has no blue to hold back. Orange over an overcast sea costs two stops and changes nothing except the shutter speed, which, to be fair, is sometimes the reason it is there. For a sky with no blue, a graduated grey filter, or simply printing the sky down later, does what colour cannot.

Stacking

A red filter and a ten-stop grey filter together need thirteen stops: a metered 1/125 s becomes a little over a minute, before reciprocity. Two pieces of glass also mean four more surfaces to collect spray. Wipe them, check the corners for vignetting on a wide lens, and keep the eyepiece covered during the exposure; light leaks backwards through a viewfinder far more readily than anyone expects.

Pushing two stops on a grey morning

2026-08-17T08:00:00Z

The light on the breakwater before nine is flat and about three stops short of what a 400-speed film wants at a hand-held shutter speed. Rating the roll at 1600 and extending development is the usual answer, and it works, with two costs worth knowing in advance.

What changes

Shadows do not gain detail from longer development; they were never exposed. What grows is contrast in the mid-tones and highlights, and grain along with it. On an overcast day that extra contrast is welcome. Under direct sun it is not, and a one-stop push is the limit.

Times that worked

Rated at	Dilution	Time at 20 °C	Agitation
400	1+1	13 min	10 s each minute
800	1+1	16 min	10 s each minute
1600	stock	12 min 30 s	10 s each minute

Treat these as a starting point. Water hardness, the thermometer and the way the tank is turned all move the result by more than the difference between two published charts.

The roll in question, and the same film in two other developers, is in a later note.

Salt, sand and mechanical shutters

2026-07-02T08:00:00Z

A camera that spends a season near the surf fails in a predictable order: first the focusing helicoid turns gritty, then the slow shutter speeds drag, then the light seals turn to paste. None of it is sudden and most of it is preventable.

Wipe the body with a cloth dampened in fresh water the same evening, then dry it.
Change lenses with your back to the wind, body pointing down.
Keep a clear filter on the lens: a filter is cheaper than a front element.
Do not store the camera in the bag it travelled in; the bag holds the damp.

Once a year the slow speeds are worth timing against a phone recording at 240 frames per second. One second that lasts a second and a half means the escapement needs cleaning, not a longer exposure table.

Surf over rocks, twenty seconds. FP4 Plus behind ten stops of grey glass.

Fixer does not last forever: counting rolls

2026-06-14T08:00:00Z

Developer announces its own death: the negatives come out thin. Fixer does nothing of the kind. A tired bath still clears the film to the eye and leaves behind silver compounds that stain and fade over years, long after anyone remembers which bottle was to blame.

The clip test

Keep the leader that is cut off before loading the reel. In room light, put a drop of fixer on the emulsion side, wait thirty seconds, then drop the whole piece into a small glass of the same fixer and start a watch. The moment the drop's spot can no longer be told from the rest is the clearing time.

Fix for twice the clearing time, three times for tabular-grain films.
Write the clearing time of the fresh bath on the bottle.
When it has doubled, the bath is finished, however many rolls that took.

Counting anyway

A litre of rapid fixer at 1+4 is rated by its makers for roughly two dozen rolls of 35 mm. Tick them off on a strip of tape on the bottle. The count and the clip test should agree; when they do not, believe the clip test, because the count knows nothing of how much developer was carried over or how long the bottle stood half empty.

Film area	Counts as
35 mm, 36 exposures	1 roll
120	1 roll
35 mm, 24 exposures	⅔ roll
4×5 sheet	¼ roll

Washing with little water

Running water for twenty minutes is not needed with a non-hardening rapid fixer. Fill the tank with water at the working temperature and invert it five times; empty it, refill, invert ten times; empty, refill, invert twenty times. Three tanks of water, and the film is washed to an archival standard. In a house on a meter, or one with a small cistern, that matters.

A last bath in distilled water with a single drop of wetting agent keeps the drying marks away where the tap water is hard. More than a drop leaves streaks of its own.

What to do with the old bath

Used fixer carries dissolved silver and should not go down the drain. Collect it in a canister; a twist of steel wool left in it for a week plates most of the silver out as a black sludge, and many municipal recycling yards take the rest with photographic or household chemicals.

Scanning at home with a camera and a light panel

2026-05-21T08:00:00Z

A copy stand, a macro lens and an even light source resolve more from a 35 mm frame than most flatbeds do, and take a tenth of the time. The weak points are flatness and stray light, in that order.

Flatness

Film curls across its width. A holder that grips both edges is enough for medium format; 35 mm usually needs a mask that presses the rebate. Stopping the lens down to f/8 covers what remains.

Stray light

Mask the panel so that only the frame is lit, and switch the room lights off. Flare lowers the contrast of the densest part of the negative, which is the highlights of the picture.

Inversion

Set the white balance on the film base, expose so that the base sits just below clipping, invert, and only then adjust contrast. Doing it in another order is the common reason for flat, muddy scans.

Scans are only as findable as the negatives behind them: the numbering used here is in the note on keeping negatives.

Drying film in a damp house

2026-04-18T08:00:00Z

Every white speck on a print is a piece of dust that settled while the film was wet. Wet gelatin is soft and sticky for the first half hour, and after that the speck is part of the negative. The cure is not a cleaner house; it is still air.

The bathroom method

Run the shower hot for two minutes with the door closed, then turn it off. Steam takes the floating dust down with it as it settles.
Wait five minutes. Hang the film from a line over the bath with a weighted clip at the bottom.
Close the door and stay out. Opening it to check moves more dust than the checking is worth.

In a house by the sea the air is rarely dry, and drying takes its time: two hours in summer, four in winter, overnight when the heating is off. Film that feels dry at the top can still be tacky at the bottom where the water ran to. Cut it only when the whole strip has the same curl.

To wipe or not

A squeegee removes water and, sooner or later, draws a scratch down thirty-six frames. Two clean fingers, wetted in the final rinse and run once down the strip, do the same job with less risk. Best of all is to touch nothing: a final rinse in distilled water with one drop of wetting agent sheets off on its own.

Mark on the negative	Cause	Next time
Round pale spots	Droplets dried in place	Distilled final rinse, wetting agent
Streaks along the length	Too much wetting agent	One drop per tank, no more
Sharp-edged specks	Dust on wet emulsion	Steam the room, close the door
Fine straight scratches	Squeegee or gritty fingers	Stop wiping
Strong curl across the width	Dried too fast, air too dry	No hair dryer; let it take hours

After drying

Cut into strips of six on a clean sheet of paper, not on the table, and sleeve them at once. A strip left curled on a shelf for a week collects what the bathroom was meant to keep away. Roll film curls along its length when the air is dry; a night under a heavy book, inside its sleeve, flattens it enough for the scanner.

If dust got in anyway, do not rub. Re-wash the strip for five minutes, give it the distilled rinse again and hang it once more. Gelatin swells, lets go of most of what was resting on it, and the second drying is usually cleaner than the first.

Long exposures at dusk and reciprocity

2026-03-09T08:00:00Z

Past about one second most films respond less than the meter promises. For the water to turn to mist on a slow emulsion the corrected times get long quickly.

Metered	Exposed for
1 s	1 s
4 s	6 s
15 s	35 s
30 s	1 min 30 s
1 min	4 min

The figures are for the traditional cubic-grain stock used here; tabular-grain films need much less correction. Light falls while the shutter is open at dusk, so meter again half-way and add what was lost.

Pier lamps, four minutes. Acros II, which hardly needs correcting for the time.

The same arithmetic for other films, with a chart, is on the reference page.

The same roll in three developers

2026-02-02T08:00:00Z

One long roll of 400-speed film, the same breakwater from the same spot, bracketed, then cut in three in the changing bag. Each third went into a different developer at the maker's time. The differences are real and smaller than their reputations.

Developer	Dilution	Time at 20 °C	Grain	Sharpness	Shadow speed
General-purpose powder (ID-11, D-76)	1+1	13 min	Fine, even	Good	Full
Syrup concentrate (HC-110)	B, 1+31	5 min	A little coarser	Good	Slightly less
Rodinal type	1+50	11 min	Coarse, crisp	Highest	About ⅓ stop less

What that means in a print

At the size of a postcard the three cannot be told apart. At 30×40 cm the powder developer gives the smoothest sky, which matters by the sea because sky is most of the frame. The Rodinal strip has edges that look cut with a knife and a sky with texture of its own; on a picture of rock and weed that is a virtue, over open water it is noise.

Breakwater at low water, before nine. HP5 Plus rated at 1600, 1/60 s at f/8.

Convenience is a real property

The powder has to be mixed a litre or more at a time at fifty degrees and keeps for a few months in full bottles. The two liquids keep for years as concentrate and are mixed by the syringe for one tank. For someone who develops twice a month, that settles the question before grain comes into it.

Starting times for the films used here

Film	Powder, stock	Powder, 1+1	Syrup, dil. B	Rodinal, 1+50
HP5 Plus, 400	7 min 30 s	13 min	5 min	11 min
FP4 Plus, 125	8 min 30 s	11 min	9 min	15 min
Tri-X, 400	6 min 45 s	9 min 45 s	4 min 30 s	13 min

All at 20 °C with ten seconds of agitation each minute. They are starting points taken from the makers' sheets and rounded; check the current sheet for the batch in hand, and change one thing at a time. A thermometer that reads a degree high does more to a negative than the choice between any two of these bottles.

What was learned

Pick one developer and stay with it for a year. The strip that looked best here was not the one from the most admired bottle; it was the one whose exposure happened to be right.

Stand development: one hour, no hands

2026-01-11T08:00:00Z

Stand development is the method for the roll that went wrong in an interesting way: half of it shot in fog, half against the sun, some frames metered and some guessed. A very dilute developer left alone for an hour works on every frame until the developer next to the emulsion is spent, and the dense parts spend it first. Highlights stop early, shadows keep going. Contrast evens out on its own.

The recipe used here

Step	What	How long
Pre-soak	Water at 20 °C	3 min
Developer	Rodinal type, 1+100, at least 5 ml of concentrate in the tank	60 min
Agitation	Gentle inversions for the first 30 s; one slow inversion at 30 min
Stop	Water, two changes	1 min
Fix and wash	As usual

The five millilitres are not optional. At 1+100 a small tank holds barely three, and a developer that runs out before the hour is over leaves the whole roll thin. Use a larger tank with a single reel at the bottom, or dilute a little less.

What it costs

Bromide drag. By-products of development are heavier than water and sink, and with nothing stirring them they leave pale streaks below the sprocket holes and under any dense shape. A plain sky shows every one of them.
Uneven edges. The top of the reel and the bottom do not get the same hour.
Grain. An hour in a high-acutance developer makes a 400 film look like an 800 film.

The single inversion at half time, sometimes called semi-stand, removes most of the streaking and keeps most of the compensation. True stand, with no agitation at all after the first minute, is for rolls with no sky in them.

Fog bank, no horizon to speak of. HP5 Plus at 400, 1/125 s at f/11.

When it earns its place

A roll of rock pools at noon, where wet stone and the sky reflected in the pool are eight stops apart, comes out of stand development printable on a normal grade of paper. A roll of unknown age and speed found in a second-hand camera has one chance, and an hour in dilute developer is the best single guess for it. A roll of evening seascapes, half of every frame smooth sky, belongs in an ordinary developer with ordinary agitation.

Temperature and patience

The tank will drift towards room temperature over the hour, and it matters far less than with a ten-minute development: at this dilution exhaustion, not time, ends the process. Set a timer, leave the room, and resist the urge to give it one more turn in passing.

Metering without a meter: Sunny 16 at the shore

2025-12-07T08:00:00Z

In full sun, set the aperture to f/16 and the shutter to one over the film speed. A 400-speed film gets 1/500 s at f/16, a 125-speed film 1/125 s. Every other condition is a number of stops away from that, and the list of conditions is short enough to memorise.

Light	Shadows look	Aperture at 1/ISO
Sun on sand, snow or open water	Hard, very dark	f/22
Bright sun	Sharp-edged	f/16
Hazy sun	Soft-edged	f/11
Bright overcast	Barely visible	f/8
Heavy overcast	None	f/5.6
Open shade, or the hour after sunrise	None	f/4

Why the beach is different

Pale sand and water throw a stop of extra light back up into the scene, which is why the first row exists. A meter pointed at the same scene is fooled in the other direction: it sees all that brightness, assumes the world is mid-grey, and gives a reading that turns white surf into grey porridge. Here the rule is more reliable than the instrument.

Negative film forgives one way

Black-and-white negative film tolerates two stops of overexposure with nothing worse than a dense negative, and less than one stop of underexposure before the shadows empty. When unsure between two rows of the table, take the lower one. The old advice to expose for the shadows and let development take care of the highlights is the same idea said more grandly.

Ninety seconds, half an hour after sunset. FP4 Plus, f/16, orange filter.

Past the bottom of the table

The rule runs out at dusk, where a stop of light goes every few minutes and the eye adapts fast enough to hide it. A few fixed points help.

Scene	At ISO 100, f/8
Ten minutes after sunset, clear sky	1/15 s
Twenty minutes after sunset	1 s
Thirty minutes after, horizon still glowing	8 s
Harbour lights, sky nearly dark	30 s
Full moon on the water, no other light	4 min

All of these are before the film's own correction for long times, which at eight seconds already adds a stop on most traditional emulsions. Bracket towards more exposure, never less.

Practice

Guess before every meter reading for a month and write both down. By the end the guess is within half a stop nine times out of ten, and the meter can stay in the bag on the days when the battery has died in the cold, which near the sea is most days in January.

Sleeves, boxes and a pencil: keeping negatives

2025-11-16T08:00:00Z

A properly fixed and washed black-and-white negative lasts longer than any way of copying it invented so far. What destroys negatives in practice is not chemistry. It is damp, and not being able to find the right strip.

What to keep them in

Material	Good	Bad
Polypropylene or polyester pages	Inert, clear, contact-print through them	Hold static, attract dust when new
Glassine envelopes	Cheap, breathe	Not clear; can stick in real damp
Unbuffered paper folders	Breathe best, last longest	Every look means handling the film
PVC pages	None	Give off plasticiser, fog and stick over years

If a page smells of a new shower curtain, it is PVC and should not be near film. The pages go in a box, not a ring binder standing open on a shelf; a box keeps out light and slows down every change in the air around the film.

Damp is the enemy near the sea

Above about sixty per cent humidity gelatin becomes food for mould, and mould etches a pattern into the emulsion that no washing removes. A house near the water sits above that figure for much of the winter.

Keep the boxes in a lived-in room, not in the cellar, the loft or the room where the chemicals are.
Put a bag of silica gel in each box and dry it out in a low oven twice a year.
Do not seal film that is not completely dry. A sealed box keeps damp in as well as it keeps it out.
Look through one box every spring. Mould starts at the edges, as fine grey threads.

Being able to find it

Every roll gets a number made of the year and a running count: 26-041 is the forty-first roll of 2026. The number goes on the page in soft pencil, on the back of every print, and into the name of every scan. A notebook holds one line per roll.

Roll	Date	Film, rated at	Developer, time	Where
26-039	02.08	FP4 Plus, 125	Powder 1+1, 11 min	North groynes, ebb
26-040	09.08	HP5 Plus, 400	Powder 1+1, 13 min	Harbour wall, fog
26-041	17.08	HP5 Plus, 1600	Powder stock, 12 min 30 s	Breakwater before nine

Ten years on, the notebook is the most useful thing in the darkroom. It answers the only two questions that ever come up: what did I do last time, and where is that picture.

Contact sheets

A whole roll printed by contact on one sheet, through the clear page, with the roll number written in the margin, is the index to the box. A phone photograph of the page on a light panel, inverted, does the same job in a minute and is better than no index at all.