There are techniques to use to slow down an accumulation of dust and dirt on your DSLR sensor, but if you take enough photos, eventually you’ll need to clean it.
Each time photographers change lenses on their DSLRs they open up the camera to allow dust to enter. In addition, zoom lenses can bring in dust to the camera. Many zoom lenses literally vacuum in dust to the sensor area of the camera when the photographer zooms their lens in and out. Different zoom lenses have different affinities for pulling dust into DSLRs. Consumer quality zoom lenses which use external lengthening/shortening to change focal length are particularly prone to this, compared to pro level zooms which zoom internally.
Please note, I’m not suggesting anyone give up their zoom lenses. In general, I prefer zoom lenses for travel and my other work. They offer great focal length flexibility, and can take the place of many prime (single focal length) lenses. That reduces the volume and weight of one’s photographic equipment while traveling. It reduces the equipment load while daily touring too.
Here’s some techniques and ideas you can use to keep the dust and dirt off your sensor:
- This one is expensive. Purchase one of the new cameras today which have a dust reduction/removal system. For example, the Nikon D700 has one of the most advanced such systems, a quad-frequency, ultrasonic cleaning system.
- Another expensive solution, which pros use, is to have a second camera ready with a different lens. Instead of swapping lenses, they swap cameras.
- When changing DSLR lenses, change quickly, leaving the camera open to the air for a minimal period of time.
- If it’s windy, and you can’t shelter yourself from the wind, turn your back to the wind to shelter your camera.
- Turn your camera off (more on that later.). Put your front lens cap on the lens on the camera.
- Get the new lens ready by removing its rear lens cap, and hold the lens with the back facing down.
- With the camera facing down, remove the lens on the camera. Continuing to hold the camera facing down, immediately put the new lens on.
- Put the rear lens cap on the lens you’ve just removed from the camera.
- Prior to changing lenses, if the camera’s exterior is dusty, wipe it clean before changing lenses.
- Whenever you’re changing lenses in a particularly dusty area you should make the change
- in a building if one is available, or
- perhaps in a car or bus, or
- if you have no choice but to change lenses outside, try doing it in a plastic bag to protect your equipment.
- Whenever the DSLR lens opening is open, except during cleaning, keep it facing down to minimize the chance dust will get into the sensor area.
- Whenever the DSLR is idle without a lens, for more than a few moments, make sure the lens opening is covered with the camera cap.
Of course, pros don't have a second camera primarily to avoid changing lenses in dusty conditions. The second camera is a backup in case something happens to the primary camera, and permits quick changes between lenses to avoid missing great photographic opportunities.
Some photographers suggest not removing the rear lens cap on the new lens until you remove the lens on the camera, then swap the cap to the other lens. I think this is a poor procedure. It extends the time camera’s lens opening is open, far too long. After all, it’s much easier to clean a lens than a sensor. The best lens changing procedure is one which maximizes protecting the camera’s sensor from getting dirty.
I do agree, that before swapping lenses you must turn the camera off. It’s to protect the camera’s light meter. I blew out a light meter many years ago by accidentally leaving the camera on while changing a lens. I accidentally faced the camera to the sky, and the light coming into the camera through the lens opening blew the meter out.
Be safe, turn off your camera whenever swapping lenses.
If you do anything special, not mentioned above, to keep your camera sensor as dust free as possible, let everyone know in the comment area below. We’d all like to hear from you.