Photographing frost, fog and snow without grey, muddy pictures

Snow, fog and heavy frost come out grey because your camera's meter assumes every scene averages out to a mid tone. Faced with a mostly white view, it darkens the picture to compensate. The fix is to add positive exposure compensation, usually somewhere between +0.7 and +2, until the white looks white again. Get that right and a still, frosty morning becomes one of the easiest times of year to make a striking picture.

Why the camera gets white wrong

A light meter measures how much light comes back from the scene and sets an exposure that would make the average of it a middling grey. That works for a typical street or garden. It fails when the scene is unusually bright, such as a snowfield, or unusually dark, such as a black dog on a dark sofa. Canon's guide to creative snow photography describes exactly this: when a large proportion of the frame is white, the meter is fooled into underexposing.

Fog has the same problem in a gentler form. It lightens everything, so the meter darkens it, and the mist ends up a dull, dirty tone instead of the luminous haze you saw.

How much compensation to add

In aperture priority or a similar semi-automatic mode, use the exposure compensation dial or menu. Canon's example of an overcast snowy scene used +0.7, and on a bright sunny day with snow filling the frame you may need nearer +1.5 or +2. In manual mode, simply give the picture more exposure than the meter suggests. The aim is that snow or mist looks brighter than grey without losing all texture.

Use the histogram if your camera shows one. You want the bulk of the graph pushed towards the right, but not jammed against the edge, which means the brightest parts have lost all detail. On a phone, tap on the scene and slide the exposure up a little; most phones also handle snow better if you avoid pointing them at the brightest patch.

Our article on aperture, shutter speed and ISO explains what the camera changes when you dial in compensation.

When frost and fog are most likely

The Met Office explains radiation fog as a winter event that forms on clear, calm nights. Heat escapes from the ground, the air just above it cools, and moisture condenses into fog. Too much wind mixes the air and prevents it, and completely still air may give only dew. Radiation fog usually lifts after sunrise as the ground warms, except on high ground, where it can linger.

That gives photographers a simple rule. If the evening forecast is for clear skies and light winds after a damp day, set the alarm. Valleys, river meadows and low fields are where cold air and fog collect first. Arrive before sunrise, and you may have twenty minutes to an hour of mist before it burns off.

The Met Office page also describes rime, the feathery ice that builds up on the windward side of objects when supercooled fog droplets freeze onto them. It is more common on hills and high ground, and it turns fence wire, grasses and gorse into delicate sculptures.

Subjects that reward getting up early

• Frosted leaves and seed heads. Get low and close, with the sun behind or to the side so ice crystals sparkle. A plain dark background makes them stand out.
• Trees in fog. A single tree or a line of them fading into mist is a classic composition. Distance reads as layers of grey, each lighter than the last.
• Footprints and tracks in snow. Low side light picks out shape and depth. Midday light flattens them.
• Breath, steam and smoke. Livestock, a kettle on a camping stove or a chimney all show up beautifully in cold air when backlit.

Fog hides clutter, which makes it a gift for simple compositions. Put a strong shape such as a gate, a lamppost or a figure in the frame and let the mist do the rest.

Colour: keeping white neutral

Snow in shadow picks up the blue of the sky, and on a sunny day that can be lovely or can look like a cold cast. Auto white balance usually handles it, but if your snow scenes come out too blue, try the cloudy or shade preset, or warm the picture slightly in editing. In golden light at dawn the warmth is the point, so leave it alone. Our Snapseed walkthrough shows how to adjust white balance and exposure on a phone in a couple of minutes.

Falling snow

A fast shutter speed freezes flakes as dots; a slower one, around 1/30 second, turns them into short streaks that show movement. Canon's guide adds a creative option for night or a dark background: fire a flash, ideally angled upwards and at low power, so nearby flakes light up like stars against the darkness. Flash pointed straight ahead tends to light the nearest flakes too strongly, so experiment.

Looking after your kit in the cold

Batteries lose charge quickly in low temperatures. Keep a spare in an inside pocket and swap when the first one fades. When you come back indoors, the camera will fog up as warm, moist air meets cold glass. Put it in a sealed bag or keep it in the camera bag before you go inside, and let it warm slowly over an hour or so before opening it. Wipe off snow before it melts into seams, and avoid breathing on the lens to clean it in freezing air, since the moisture turns straight to ice.

Above all, take care on icy ground. A beautiful sunrise is never worth a fall on a frozen path, and fog can make roads and riverbanks more dangerous than they look.