Cleaning Sensor and Lenses in the Field

Dust spots show up in skies at small apertures and ruin long sessions of work if you don't catch them. Most are easy to remove on location.

Find the dust

Photograph a clear sky or a white wall at f/16–f/22, defocused. Open the file and boost contrast: dark blobs are dust on the sensor. Remember the image is inverted — a spot at the top right of the photo is at the bottom left of the sensor.

Prevent it

• Change lenses with the camera facing down, out of the wind, and quickly.
• Keep rear lens caps and body caps clean; dust on them ends up inside.
• Many mirrorless cameras close the shutter when powered off — enable that setting if yours has it.
• In dusty places such as sand dunes, avoid lens changes entirely or carry two bodies.

Cleaning the sensor

Work from gentlest to most invasive:

1. Built-in cleaning: run the camera's sensor-shake cleaning cycle.
2. Blower: hold the camera facing down and puff air with a rubber hand blower. Never use canned air — propellant can spray onto the sensor.
3. Gel stick: a sticky polymer tip lifts stubborn particles. Press gently, don't drag.
4. Wet swab: a sensor swab of the correct width with a few drops of sensor cleaning fluid, one pass in each direction. Use a fresh swab each time.

Make sure the battery is charged; the shutter must not close during cleaning on DSLRs. If you are unsure, a camera shop can clean the sensor for you.

Cleaning lenses and filters

• Blow loose grit off first — wiping sand across glass scratches it.
• Use a lens brush, then a clean microfiber cloth in circular motions from the center outward.
• For smudges and salt haze, use a drop of lens cleaning fluid on the cloth, not directly on the glass.
• Keep a separate cloth for filters; filters get dirty faster.

Removing remaining spots

A few spots can be healed in your RAW editor. Use a spot-visualization tool or a high-contrast view to find them, and sync the fix across a whole sequence shot at the same aperture.