The idea of cleaning your camera’s sensor fills many photographers with dread. It may seem difficult or complicated but it is actually much more straightforward than you may think. In this article, I will give you a simple guide on how to check for sensor dust and how to effectively clean your camera’s sensor.
Apologies for the disclaimer but this is just a guide to best practices. You should take extreme care in carrying out this task as it is very easy to damage your sensor rendering your camera in need of vital and expensive repairs.
Table of Contents
What Is Sensor Dust and What Does It Look Like?
Every time you change a lens on your camera, you are exposing the inside to potential dust and dirt contaminants.
You should try to protect the inside of your camera as much as possible when changing lenses—it goes without saying that you should not change a lens in an environment that will lead to unnecessary dirt entering your camera, such as a sandy beach or on a windy day—but obviously it is not always possible to do this. Inevitably, dirt and dust will enter the camera and ultimately show up in your images.
Sensor dust will show up in your images as blurry spots which will look something like the spots circled below:
There are a few important things to note:
- You may see dust in your viewfinder but this dust will not show up on your images themselves.
- It is worth pointing out that you may not see any sensor dust if you shoot at wide apertures (such as f/2.8) as the depth of field is wide enough to throw these spots out of focus rendering them very difficult to see (if you can see them at all).
- You can tell that it is dust or dirt on your sensor when you see the same spots appearing on multiple images in the same places.
- Although a highly detailed scene may hide the dust, it is still there and will naturally become visible the next time you take a photograph.
- You may see dust on the mirror (if you use a DSLR), but this won’t be recorded on an image and should be removed using an air blower. DO NOT use compressed air as this is too powerful and may damage your camera.
- DO NOT touch the mirror (or the sensor) with ANYTHING as both are extremely fragile and easily damaged, scratched, or marked.
How to Test to See Sensor Dust
- A simple way to check and see if you have sensor dust is to set your camera to a small aperture such as f/16 or f/22.
- You should also set your camera to the lowest ISO as you are not worried about noise at this stage.
- Take a photograph against something bright white (such as a white wall, piece of paper, or cloudy sky) and gently move the camera slightly as you take the photo to help blur the photo and make the dust more visible.
- Then to check for dust, either inspect the back LCD screen at 100% or load the image into your computer to make this task a little easier.
- If you see signs of dust (as described and shown above) then you know you need to clean the sensor.
Before You Attempt to Clean Your Sensor
I would suggest that you first try to use your camera’s auto-clean mode if it has one to see if this makes a difference in removing dust or dirt. Some cameras do this automatically when turned on or off but it is worth trying first.
Important: Make sure that your camera’s battery is fully charged as it may turn off mid-clean and damage the sensor if it runs out of power.
Things You Will Need
- Cleaning swabs that are lint-free and designed for your camera’s specific sensor size.
- Cleaning solution designed for camera sensors.
- Bulb blower for manually puffing dust away with air.
- Flashlight or headlamp to see inside the camera and inspect the body.
- Sensor loupe, a great cheap item that is a magnifier with LED lights allowing you to clearly and easily see the sensor and inspect for dust and dirt.
How to Dry Clean Your Sensor
- Find an area that is as free of dust and wind as possible.
- If you are using a DSLR: With a full battery and no lens on your camera, look for the menu option to manually clean your camera. Check your manual if you can’t find this option. When you select this mode, you will hear the mirror lock back and reveal the sensor if you are using a DSLR. Note that you just need to power off your camera to release the mirror back to its usual place in front of the camera.
- If you are using a mirrorless camera: Your sensor should be exposed when you take off your lens or body cap.
- Holding the camera upside down so the LCD screen is facing the ceiling, use the manual air blower to blow air into the camera onto the sensor. Be extremely careful NOT to touch the sensor with the tip of the blower. The best practice is not to put the tip of the blower inside the camera at all. Again do not use compressed air.
- After a few blasts of air, turn off the camera and replace the lens. You should take another test shot (as above) to see if this has removed the dust or dirt that was on the sensor. If it has then there is no need to take any further steps. If it remains, then you will likely need to proceed to a ‘wet’ clean of the sensor.
How to Wet Clean Your Sensor
- Remove the lens and place the camera on a surface with the LCD facing the floor.
- Select the manual cleaning option to lock up the mirror on a DSLR. Remove the lens or body cap to expose the sensor on a mirrorless camera.
- Remove a sensor cleaning swab and using the air blower a few times, blow air to remove any odd pieces of lint that may be stuck to the swab.
- Add two (or three drops max) of the solution to the tip of the swab. Do not oversaturate the swab or you will leave streaks on the sensor. Less is definitely more in this case!
- With great care place the swab onto one side of the sensor and with not too much force, gently move the swab across the sensor in one smooth motion. When you get to the other side, turn the swab over and repeat the process starting from the far side back to where you started. Again, do this in one smooth motion with no great force.
- At this stage, I use a loupe and inspect the sensor to see if I can see if the dust has been removed. If you are not sure, turn off the camera and replace the lens and take a further test shot to inspect for dust.
- If you see some dust remains then you will need to repeat the process but it is important to use another clean new swab. Do not reuse a swab.
If you see streaks on the sensor then this means that you have used too much solution. Wait a few minutes and then repeat the process with less solution. Two drops are usually enough.
You will now have a clean sensor. When done properly with the correct equipment it is quite a simple process to clean the camera’s sensor. Although a little daunting the first time you do this, you will be saving yourself the unnecessary expense and inconvenience of being without your camera by using a professional cleaning service.
I hope this tutorial helps to explain how to clean your sensor in a straightforward way.
About the author: Antony Zacharias is a Florida-based Commercial and Fine Art photographer with roots in London. To see more of his work, head over to his website or give him a follow on Facebook, 500px, and Instagram.