How to check if your sensor is dirty!

Published on 27 January 2021 at 03:25

The sensor is one of the most valuable, if not the most valuable, parts of our camera. It is what tansforms the light into a picture. Like our eyes.


It is also a very sensitive part, also like our eyes. It is only natural for us to be extra carefull with it and try to maintain it at the best possible condition. That means no dust, no fingerprints, or basically anything that shouldn't be there.


Despite all our efforts, some things will still end up inside there.

But how can you tell if there is something in your sensor?

There are a few simple and easy ways to find out if your sensor is dirty.

1. First of all you can physically examine your sensor with sufficient light and an illuminating lupe.

That way you establish if there is something on your sensor.

Although this will give an actual look into the sensor, it might not be enough to determine if there is something that will affect your pictures.

There is a better way to see if your pictures get affected. Simply take a picture!

2. Taking the picture.

You will need to just follow these steps/settings and take a picture.

  1. Find a clear sky during the day or a bright colored wall, well illuminated.
  2. Set your focus on manual and focus to infinity
  3. Set your apperture to the highest availabe for the lens you have, eg. f22
  4. Set your iso to 100
  5. Set your shutter speed as needed to have a perfect exposure
  6. Point the camera to the sky or the wall or a piece of white paper with enough light and take a photo.

Now import that photo to your editing programm, i use Lightroom.

Initially you might not notice anything, or maybe some dark spots in the sky. So to make sure that there aren't any more hiding over there, we will do the following:

  1. Increase the contrast
  2. increase the texture
  3. increase the clarity
  4. Slightly increase the dehaze option

See what happens then!

Trust me the more you will look, the more you will find.

It is ok! You can always remove them with the heal tool.

Or you can clean your sensor!

Check out my post, on how to clean your camera's sensor!


Now not all dark spots that show up n your picture, are necessary coming from sensor dust. Some might be from dirt in your lens or in your mirror!


So how do you dintinguish these?

Let's see!

If there is something on your lens it will apear as if there is a spot in your picture with les contrast. Slightly darker, but quite biger than sensor dust. Also visible in all aperture range and not only in the sky.

It is also vissible in the bokeh, like this.

Now if you can see it in the viewfinder but not in your picture, then probably it is stuck in your mirror, or in your viewfinder and has no effect in your pictures.

No matter what you try, dust will get in there. Especially if you are in a windy and dusty inviroment, such as the desert. Don't get discouraged, try to maintain your equipment as clean as possible and you after you finish your job, just give it a good clean up. It is all about enjoying taking the pictures. The camera is our tool and there is always a way to maintain it in good condition.

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