Cleaning the camera sensor – a step-by-step guide

Cleaning the sensor is the most common maintenance task for a camera with interchangeable lenses. Dust gets inside the camera every time you change the lens, and before long it will appear as dark spots in your photos. Cleaning the sensor isn’t difficult if you use the right tools and take your time. This guide explains how to tell if your sensor is dirty, what equipment you’ll need, and how to clean the sensor step by step. If you’d rather not do it yourself, we can clean the sensor for you At our Kouvola shop.

How can you tell if a cell is dirty?

Dust particles on the sensor appear in the image as dark, soft-edged specks that are always in the same place in the picture. They are most clearly visible at a small aperture against a uniform background, for example when photographing the sky. At a large aperture, the debris is often so blurred that it goes unnoticed.

Here’s how to carry out a cell test:

1. Set the ISO as low as possible, for example 100.
2. Set the aperture to f/16 or f/22.
3. Take a photo of a cloudless sky or a white wall. It doesn’t matter where the focus is; the photo can be out of focus.
4. Zoom in on the image on your computer and look for dark spots and patches. The ‘Dehaze’ or ‘Contrast’ adjustment in your image-editing software will make them stand out more clearly.

Please bear in mind that the image is a mirror image: the debris visible at the top of the image is actually at the bottom of the sensor.

Try dry cleaning first

Most of the debris in the cell is loose dust, which can be removed using an air pump. Always start with this, and only move on to wet cleaning if the debris does not come away.

1. Activate the camera’s built-in sensor cleaning (shake) function, if the camera has one.
2. Remove the lens and hold the camera so that the sensor is facing downwards. This will allow any loose dust to fall out of the camera.
3. Blow into the cell a few times with firm puffs with an air pump. Do not touch the tip of the pump against the cell.
4. Take another test photo and check the result.

Do not use a compressed air cylinder. Liquid may leak from a compressed air canister, leaving marks on the cell that are difficult to remove. Also, do not blow into it with your mouth, as droplets of saliva will stick to the cell.

Equipment required for wet cleaning

• Fully charged battery
• Two cell cleaning pads and cell cleaning fluid. The easiest option is a ready-made cleaning kit, such as UES Full Frame- or UES APS-C - a sensor cleaning kit containing both cleaning fluid and swabs.
• Air pump
• Good light or cell magnifier, which allows you to view the rubbish directly from the cell (not compulsory)

Choose a cleaning brush of the right size

The width of the squeegee must match the width of the cell so that the cell is cleaned in a single stroke from edge to edge.

Cell size	Width of the blade	Example cameras
Full-frame	24 mm	Sony A7 series, Canon EOS R6, Nikon Z6
APS-C	16 mm	Fujifilm X series, Sony A6000 series, Canon R7, R10, R50
Micro Four Thirds	12–14 mm	OM System, Olympus, Panasonic Lumix G

Cleaning the cell, step by step

1. Prepare your workspace. Choose a dust-free and well-lit place. Wash your hands and lay out two spatulas on a clean surface.
2. Set the camera to cleaning mode. On a system camera, select ‘Manual sensor cleaning’ from the menu; this will raise the mirror and open the shutter. On many cameras, this mode requires the battery to have sufficient charge. On a mirrorless camera, the sensor is visible when the lens is removed, but if the camera has image stabilisation, switch it off before cleaning to ensure the sensor remains stationary.
3. Blow away any loose dust with an air pump before wet cleaning, to prevent grains of sand from scratching the surface of the cell.
4. Moisten the first piece. Apply 2–3 drops of cleaning fluid to the tip of the scraper so that the part that comes into contact with the cell is thoroughly damp but does not drip.
5. Wipe the sensor in a single stroke. Place the blade at an angle of approximately 45 degrees to the edge of the cell and pull it smoothly to the other edge. Turn the blade and pull it back along the other side. Light pressure is permitted, but do not rub.
6. Dry with a dry spatula using the same movements. If any streaks remain on the cell, repeat the drying process.
7. Check the result using a test image. If there is still any rubbish left, repeat the cleaning process with a new scraper. Never use the same scraper twice.

You’ll find all the equipment you need sensor cleaning supplies from the department.

This way, you won’t damage the sensor

• Do not touch the cell with your fingers, the tip of the pipette or a cotton bud.
• Do not use spectacle cleaning fluid or alcohol that is not intended for use on the sensors.
• Do not use a brush or cloth intended for cleaning the lens on the sensor.
• Do not rotate the scraper. Any dirt that came loose last time may scratch the surface of the cell.
• If there are oil splashes or stains on the radiator that do not come off after a couple of attempts at cleaning, leave the cleaning to a professional.

This keeps the sensor cleaner

• Change the lens quickly whilst holding the camera upside down.
• Avoid changing lenses in windy conditions, on sandy beaches and in dusty places.
• Always keep the body cap and the rear lens cap in place.
• Many mirrorless cameras have a setting that closes the shutter when the camera is switched off. This protects the sensor whilst changing the lens.
• You should also clean the rear lens element and the camera body’s bayonet mount with an air blower every now and then.

Cell cleaning in Kouvola – leave it to us

If you don’t want to clean the sensor yourself, bring the camera in Foto Monzan shop in Kouvola to Asemakatu 2 B. We clean the sensor using professional-grade equipment and check the result with a test image. Sensor cleaning costs 29,90 € for all cell sizes, and it is usually ready on the same day.

This service is particularly suitable if there are stains on the sensor that cannot be removed with a blower, or if you do not want to take any risks with an expensive camera. We serve customers from Kouvola and the whole of the Kymenlaakso region, including Kotka, Hamina and the Lahti area. During the same visit, you can also purchase your own sensor cleaning supplies and ask for advice on how to use them.

Frequently asked questions

How often should the camera sensor be cleaned?

When debris appears in the photos. For a photographer who changes lenses frequently, this might mean every few months; for someone who changes them rarely, it might be once a year or even less often.

Can I clean the cell myself?

Oh dear. There is a protective glass cover on the surface of the sensor, so cleaning it is safe provided you use the right tools and take care. The risks arise from using the wrong liquid, a scraper, or sand that hasn’t been blown off first.

How much does it cost to have the cell cleaned?

At our Kouvola branch, cell cleaning costs €29.90, regardless of the cell size. If you clean the cells yourself, a cell cleaning kit costs around €30 and contains enough scoops for several cleaning sessions.

What is the difference between cleaning the sensor and cleaning the lens?

If the spot appears in the same place with all lenses, there is dirt on the sensor. If it appears with only one lens or changes position when zooming, there is dirt on the lens, in which case it is sufficient to clean the lens elements.