Your black dog comes out as a blob. It is not your phone, it is its light meter.

A black dog or a black cat photographed on a phone almost always gives the same thing: a dark shape, no muzzle, no fur, with two eyes floating in it. It is neither the phone nor the animal. It is a mechanical consequence of the way the camera measures light, and it can be fixed.

1. Why it fails, exactly

A camera does not know what it is looking at. Its exposure meter starts from one simple assumption: on average, a scene is mid grey. So it sets the brightness so that the image tends towards that grey.

In front of a black animal there are two cases, and both are bad:

• The animal fills the frame. The camera reads a scene that is “too dark”, raises the brightness, and the coat turns muddy grey while the background burns out.
• The animal is against a bright background — a white wall, a window, snow. The camera reads a scene that is “too bright”, lowers the brightness, and the animal becomes a silhouette with no detail at all.

The second case is by far the most common, and it is the one we photograph without thinking: the cat on the windowsill, the dog in front of the patio doors. Backlit, a black animal is lost before you press the shutter.

2. The four fixes

Put the light behind you

This matters most and costs nothing: stand so that the daylight comes from behind you and falls on the animal's face or three-quarters. In practice, if the animal is near a window, walk around it until the window is at your back. The same cat, in the same place, at the same hour, becomes a completely different photograph.

Tap the animal on screen, then raise the exposure

Tap the screen on the coat, not on the background. A focus square appears with a small slider beside it — a sun icon on iPhone, a vertical slider on most Android phones. Slide it up by about +0.7 to +1.3.

The image will look slightly too bright on screen. That is normal, and it is the sign it is working: the black fur is no longer a flat area, it recovers its shades, its highlights and its texture. A correctly exposed coat is never pure black on screen.

Prefer an overcast sky to bright sun

This is counter-intuitive, and yet: bright sun is the worst moment for a black animal. The gap between lit areas and shadows exceeds what the sensor can record, so one goes grey and shiny while the other stays blocked up. An overcast sky is an ideal light — broad, soft, with no hard shadow. Failing that, the shade cast by a wall or a tree, in daylight.

Never use flash

Front flash flattens the fur, removes all relief and turns the eyes green. On a black animal it saves nothing; it destroys the only interesting thing, which is the texture of the coat.

3. The eyes make the photograph

On a black face the eyes are the only bright point — and they are what separates a portrait from a shadow. What to aim for is a small reflection in the eye, what photographers call a catchlight. You get it by turning the animal towards the light source, a window or open sky.

A quick test before keeping a photo: zoom in on the eye. If you can see a white dot in it, the photo is good. If there is nothing, it will print flat however sharp it is.

4. The background: light, plain, and far

A black animal needs a light background: a white wall, a sheet, tiles, the sky, snow, sand. This is true for two different reasons, and both matter.

• For the eye. Against a dark background a black animal has no outline: you can no longer tell where it begins.
• For printing. If the photo is cut out to sit on an object, you need a usable boundary between fur and background. A black cat on a charcoal sofa has none: the cut-out either eats into the animal or takes pieces of sofa with it.

One more useful detail: move the animal a metre away from the background if you can. That avoids the shadow cast right behind it, which is the worst enemy of a clean cut-out.

5. What can be rescued, and what cannot

A photo already taken can often be improved in your phone's photo app: lift the shadows, lower the contrast a little, and the coat recovers detail. This works particularly well on a recent photo shot in HEIC or RAW.

But if the coat is completely blocked up — uniform black, with no variation when you zoom in — there is no information left to recover. No setting creates detail that was never recorded: lifting the shadows will only reveal grey noise. In that case reshooting takes five minutes and gives an incomparably better result.

6. Which object to print on: the contrast reverses

This is the part everyone gets wrong, because intuition says “black animal, black object”. It is exactly the opposite.

The full reasoning on choosing a product is in the page about pet photos, and the mug case — framing on a curved surface — is here.

7. The white animal: the mirror problem

Everything above reverses for a white cat, a golden retriever or a westie. The meter underexposes them less, but they disappear on light products: a white cat on a white mug or a natural tote fades away from a metre. They need a black t-shirt, a navy tote, a black cap — or a framed print, where printing on white keeps a border that separates the animal from the wall.

In short

Light behind you, never in front. Tap the animal on screen, then raise the exposure by about +1. Overcast rather than bright sun, never flash. Check there is a reflection in the eye. Light, plain background, a metre behind the animal. And print on a light object: white mug, framed print, natural tote. From $23.00, shipping included, printed to order in 5 to 10 working days in the UK, Europe and the US.