Camera Sensor Cleaning

Before cleaning the sensor, confirm the dust is actually on the sensor. Dust can also sit on the rear element of the lens, on the viewfinder, or on the front of the mirror. Sensor dust test: Set the camera to f/16 or f/22. Point it at a clear blue sky or a uniformly lit white wall. Take a photo. Import it to your computer and view at 100% zoom. Dark spots or blobs are sensor dust. If nothing shows at f/16, there's nothing to clean. Dust on the lens rear element: Visible when you remove the lens -- you'll see it on the glass. Wipe with a lens cloth, not a sensor swab. Dust on the mirror or viewfinder: Visible when you look through the viewfinder but not in photos. The mirror and viewfinder don't affect the image. Leave these alone -- they're extremely delicate and cleaning them is usually not worth the risk. Clean only if you see dust spots in photos. Every time you open the camera body, you risk introducing more dust. Don't clean preemptively.

Before touching the sensor with anything, use the rocket blower. This resolves ~60% of dust problems. Charge your battery fully. Go to Menu → Setup → Sensor Cleaning → Lock Mirror Up for Cleaning (the menu path varies by brand -- look for "Mirror Lock Up," "Manual Cleaning," or "Sensor Clean"). Press the shutter button to lock the mirror up. Hold the camera face-down at a 45° angle. Insert the blower nozzle (don't let it touch anything inside the camera) and squeeze firmly 5--8 times. The angle lets loosened dust fall out of the camera body by gravity rather than resettling. Press the camera power off to bring the mirror back down. Put the lens back on. Test again at f/16. If the dust is gone, you're done. If it's still there, proceed to wet cleaning.

Wet sensor cleaning requires a calm, low-dust environment. Airborne dust settles on the exposed sensor faster than you'd expect. Best environment: A bathroom 10 minutes after a hot shower. The steam has settled airborne particles. Or a clean room with the AC/heating turned off (air currents carry dust). Wash your hands and dry them completely. Don't wear clothes that shed fibers (fleece, wool sweaters). Work on a clean, hard surface -- not a fabric surface that generates static. Open your sensor swabs package just before use. Don't pre-open them -- the swab surface can attract airborne dust while waiting. Have your cleaning fluid and camera within arm's reach before you lock the mirror up. Once the sensor is exposed, you want to work quickly and without hunting for things.

Lock the mirror up (Menu → Sensor Cleaning → Lock Mirror Up). Work in good light so you can see the sensor surface. Remove the swab from the package without touching the swab surface. Apply 2 drops of Eclipse cleaning fluid to one end of the swab. Don't saturate it -- you want the swab damp, not wet. Place the damp end of the swab at one edge of the sensor (left side for APS-C, left side for full frame). Press gently with even pressure and drag in one continuous motion to the opposite edge. No scrubbing. No back-and-forth. One smooth stroke. Flip the swab to the dry end. Starting from the same edge you finished on, drag back across the sensor in the opposite direction. One stroke. Done. Power off the camera. The mirror drops. Put the lens on. Test at f/16. If streaks appear: A second pass with a fresh swab and 1 drop of fluid usually clears them. Streaks are caused by too much fluid or an already-contaminated swab.

After cleaning, shoot a test at f/16 against a plain background. Import and review at 100% zoom. If spots are gone: You're done. Power down and resume shooting. If spots remain: Identify the location of remaining spots in the image. Remember that dust spots appear on the opposite side of the sensor from where they appear in the image (left in the photo = right side of sensor when viewed from the front). Do another pass with a fresh swab, targeting those areas. If you can't clear it after 2--3 passes: Stop. Repeated cleaning attempts without improvement usually mean the contamination is oil-based (from the camera's internal lubricants) or you're re-depositing dust from inside the camera. This needs an ultrasonic professional cleaning. Don't overclean. Sensor coatings are durable but not indestructible. If you're cleaning every week, something else is wrong -- a lens with a bad rear seal, or a shooting environment with excessive dust.