How Did Dust Get on My Sensor?

(18 sec.) As a lens zooms, its rear element moves in and out, moving air and dust towards the camera’s sensor.

All DSLR and mirrorless cameras get dust on their sensors. Your camera’s sensor chamber is exposed to air, and to dust and debris in the air. The digital imaging sensor is in the back of this chamber.

There’s air always in this chamber. When we attach or remove lenses or the camera body cap, this chamber is opened. The air and moisture and dust and whatever yuck outside the camera mingles with the air and moisture and dust and whatever yuck is already inside the camera.

But further, in the quick video, you can see how the rear element of a typical zoom lens moves in and out as the lens is zoomed. When the lens is mounted and operated, it pushes and pulls air around the camera chamber. Most lens barrels also change length as you focus. This moves air around inside the lens as the lens interior changes volume. This pushes or pulls air from somewhere – thru the lens barrel joints, and/or thru the rear lens mount.

Not only are we blowing existing air around the chamber, we are blowing or sucking air from outside. And that air contains any moisture, airborne cooking particles, dust, salt spray, pet hair and dander, and fibers from that snazzy new sweater you’re wearing. These end up in the camera chamber, and on your sensor.

So, never changing lenses is not an effective way to avoid sensor dust! And it’s very limiting to your photographic creativity!

In the old film days, we bought a new sensor for every image we made – in rolls of 12, 24, or 36 exposure film! Even if dust got onto the film, it only affected a single image. In the digital age, we use the same sensor for 50,000, 100,000, even 300,000 pictures! Over time, your sensor collects dust just like your coffee table collects dust.

And every spec of that dust casts a shadow onto your image. It shows up as a dark spot or blob on every image. If you shoot at a wide aperture like f/2.8, it’s softly out of focus so it’s less noticeable. But these spots and blobs are there, softening your image in a way that’s out of your control. Shoot a daytime sky at f/22. Those blobs and spots will be in focus and will scream at you! Image after image. Lots and lots of work in Lightroom or Photoshop. And details lost.

Getting dust on your sensor is inevitable, and it has happened to your camera. See for yourself! Try shooting that bright sky at f/22. Zoom in on the image and check the corners. Ya, them… Yuck.

Just like your coffee table, the dust and detritus of life needs to be removed. I can help you with your camera sensor housekeeping. Book an appointment today!!!

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