Why are my photos coming out too dark or too bright?

Cameras and phones do not know what they are looking at. They measure light and aim at an average, and every predictable exposure error comes from a scene whose average is not what the meter assumes. Once you see that, the correction is obvious every time.

Step by step

1. Understand the assumption.Reflected-light metering assumes the scene averages out to a middle tone — roughly the brightness of a grey card, or of grass in sun. That assumption is right often enough to be useful and wrong in predictable ways.
2. Recognise the classic failures.Snow, a beach, a white wall, a bride's dress or a bright sky come out grey and dull because the meter darkens them towards the middle. A black cat, a dark suit, a night scene or a dark stage come out washed out and grey because the meter brightens them.
3. Use exposure compensation.Marked with a plus/minus symbol, usually a dial or a button on a camera and a slider on a phone. Add one to two stops for snow and bright scenes; subtract one to two for dark ones. It works in every automatic and semi-automatic mode.
4. Read the histogram, not the screen.The histogram is a graph of how many pixels sit at each brightness, dark on the left, bright on the right. A spike jammed against the right edge means highlights are clipped; against the left edge means shadows are crushed. Screens change with ambient light and their own brightness setting; the histogram does not lie.
5. Turn on the highlight warning.Most cameras can flash any clipped area on playback. It is the fastest possible check and it saves the shots that matter. Anything flashing white has no recorded detail at all.
6. Protect the highlights first.Sensors record far more recoverable information in the shadows than in the highlights. A file exposed a little dark can be lifted convincingly. A clipped highlight contains nothing to recover — it is a flat area of maximum value.
7. Change the metering mode when it helps.Evaluative or matrix metering looks at the whole frame and is right most of the time. Spot metering reads a small central area and is the tool for a lit face against a dark background, or a subject against a bright sky — but you must then place that spot deliberately.
8. Check whether the mode is fighting you.In manual mode, exposure compensation does nothing unless ISO is on automatic. If the dial appears to have no effect, that is usually why.
9. Reset compensation before you put the camera away.Compensation persists. A whole shoot at minus two stops because of a snow scene last month is a common and demoralising discovery.

Tips

• The rule is simple: bright scene, add exposure. Dark scene, subtract it. It is counter-intuitive precisely because the meter has already moved it the wrong way.
• In JPEG, err slightly dark. In RAW, err slightly bright without clipping — that gathers more light and gives cleaner shadows when you pull it back.
• If your camera can show a live histogram in the viewfinder, turn it on. Exposure stops being guesswork within a week.

Common mistakes

• Judging exposure on the rear screen — The screen brightness is a setting, and it looks different in sun and indoors. Photographs that appeared perfect on a bright screen outdoors are routinely two stops dark on a computer.
• Fixing everything in editing instead — Lifting a badly underexposed file amplifies noise in the shadows. Getting the exposure right in the camera gives a visibly cleaner picture from the same equipment.

If it doesn't work

Questions people ask