How to photograph jewellery so it can be identified

Light does most of the work

Jewellery is hard to photograph for one reason: it is built to move light around. Polished metal acts as a mirror and a faceted stone as a bundle of small mirrors, so both report back whatever is in the room. What you want is a large, soft source, and the simplest one is a window on an overcast day, or a window the sun is not shining directly into. Put the piece on a table beside the glass so the light arrives from the side rather than over your shoulder.

Avoid direct sunlight. It is a small, hard source: it burns white holes into polished metal and turns every facet into a blown-out star that carries no information. Avoid the flash for the same reason, with a fault of its own – it sits next to the lens, so it lights the piece flatly and leaves one glaring hot spot in the middle of the stone, exactly where the detail is.

Background, framing and exposure

Use a plain mid-tone background: grey card, or a folded cloth with no pattern. Mid-tone matters because the phone meters the whole frame. Put a small ring on a large black cushion and the camera brightens everything to compensate, so the metal goes chalky and the hallmark washes out.

Then fill the frame. A ring occupying a tenth of the picture carries a tenth of the detail, so move in until the piece nearly touches the edges. Tap the screen on the part that matters to set focus, then drag the exposure slider down a little: a slightly dark photograph keeps the shape of the facets and the texture of the metal, while a bright one destroys both, and nothing recovers what was recorded as pure white. Brace your elbows or use the timer, and wipe the lens, since a fingerprint on it is a soft haze over everything.

Wipe the grease off, but do not polish

Finger grease is the commonest reason a photograph looks foggy, and a diamond attracts it particularly well. A few seconds with a dry, soft, lint-free cloth lifts most of it. For plain gold or platinum set with diamonds, warm soapy water and a very soft brush, rinsed and dried, is safe.

It is not safe for everything. Keep water and brushes away from pearls, opals, turquoise, emeralds, coral and anything glued or foiled, and away from plated pieces, where scrubbing wears the plating through at the edges. Never use a domestic ultrasonic cleaner unless you know what every stone is.

And do not polish. On an old piece the patina in the recesses and the softened engraving are evidence of age, and buffing removes both along with a layer of metal. If the piece may be antique or inherited, photograph it exactly as it is.

The hallmark shot is the one worth the effort

A stamped mark is the strongest single piece of evidence a photograph can carry, because it is a statement from a maker or an assay office rather than an inference from appearance. Look inside the shank of a ring, on the tongue or underside of a clasp, on an earring post and on a watch case back.

Two techniques make marks readable. The first is distance: switch on macro mode if the phone has one, and come only as close as the lens can still focus. Closer than that and it hunts. If it will not lock on, back off and crop afterwards, because a sharp crop beats a soft close-up.

The second is raking light. A stamped mark is a depression, not a printed line: light from the front fills it and flattens it, while light skimming across the surface throws small shadows inside each stroke and makes the mark leap out. Tilt the piece against the window, or hold a small torch low and to one side, and shoot several angles. Photograph the mark rather than transcribing it, because worn numbers are misread and the reading turns on the exact characters.

Shoot the stone from the side as well as the top

Almost everybody photographs a ring from directly above, and that is the least informative view available: it shows outline and facet pattern and little else. The profile shows what carries weight. How deep the stone is, which is half of any estimate of its size. The girdle, thick or thin, frosted or polished. Whether there is a culet. How the stone sits in the mount, and whether the setting is open or closed at the back. A closed back is worth noticing: it is normal on older and on coloured-stone pieces, but it can also conceal a foil or a very shallow cut, and it is common in costume jewellery.

Photograph the back and underside too, since that is where solder seams, repairs, replaced claws and worn plating show. For a necklace, a separate frame of the clasp is worth as much as a frame of the whole piece.

Give the frame a scale

A photograph has no inherent size: a ring that fills the frame could be a child’s band or a heavy signet. Since an estimate of carat weight is built from measured dimensions, scale changes the numbers more than almost anything else you can supply.

The best reference is a millimetre ruler laid beside the stone, in the same plane and in focus in the same frame. Second best is a coin, named in your note. Add it as one extra frame, so the clean photographs stay clean. Better still, use real figures where you have them: a ring size, the internal diameter of a bangle, or a weight in grams from a scale that reads to a tenth of a gram. A measured weight turns a melt figure from a guess into arithmetic.

The checklist

1. Wipe finger grease off the piece with a dry soft cloth, and wipe the phone lens.
2. Set up beside a window with indirect daylight. No direct sun, no flash, no overhead spots.
3. Lay down a plain mid-tone background with no pattern.
4. Frame the whole piece from the front, filling the frame, and tap to focus.
5. Drag the exposure down slightly so the highlights on the metal keep their shape.
6. Take a second frame from the side, with the camera at the height of the table.
7. Take a frame of the back or underside, including the clasp if there is one.
8. Switch to macro, find the hallmark, light it from a shallow angle, and shoot several angles.
9. Take one frame with a millimetre ruler or a named coin beside the piece.
10. Check each photograph at full zoom before you stop, and reshoot anything soft.

Six to ten frames taken this way beat thirty taken under a ceiling light.

What good photographs change, and what they do not

Good photographs move a result from guesswork towards observation: a legible mark settles the metal and often the country and period, and a side view supports a sensible estimate of stone size. What they cannot do is weigh the metal, test its purity, see inside a stone, or establish whether a diamond grew in the ground or in a chamber – those need a scale, a jeweller and a gem laboratory. Carat rates the photographs it is given and lists what is missing, which is the quickest way to learn what to reshoot; how a reading is assembled is set out separately.