If it’s the first time for you to see dust inside your camera or your lens, you need to relax and understand something – it’s normal. Let's face it. Your camera is a dust magnet from the inside out whether it’s a DSLR, a mirrorless camera, or even a point and shoot. The only way you can truly avoid getting dust in your camera is to shoot inside an air tight-vacuumed room or put a protective suit on it. That sounds absurd but that's just reality. And since it is normal, it is best to just live with the fact that getting rid of some dust will be a life-long activity as you continue doing photography.
Do not try this at home! Photo by jeff_golden
Since there are already gazillions of resources out there on how to remove dust in your camera. I won’t be reinventing the wheel anymore and would rather give direction as to what to do when you do encounter dust. Here are some things to consider.
Two Questions to Ask After You Spot Dust Inside Your Camera
When we see dust in our camera, our obvious initial response is to find out how to get rid of it. But whether you see dust inside or outside your lens or inside your camera as you change lenses. It is still best to ask two essential questions:
“Is dust affecting my ability to compose?” and “Can the dust be seen in my images?”
Remember that presence of dust inside your camera is okay, but when your answer is “No” to any of these two questions, then it’s quite alright to just ignore it. Of course, having your camera cleaned and maintained is a good habit but being obsessive about having dirt will only disappoint you. But, if your answer is “Yes” to these questions, then it is best to figure out how to effectively remove dust.
Dust Affecting Your Ability to Compose
You look into your viewfinder and you see a speck of dirt right in the middle floating about – does it annoy you? I would be if it happened to my camera. Dust that becomes an added element as you create your shot will affect your ability to compose properly. Perhaps some may be able to simply ignore it but a normal photographer would definitely want to remove it.
Photo by peretzp
When this happens, there are four places you can check where dust usually accumulates depending on your camera – the lens, the mirror (for DSLRs), the viewfinder, and the sensor.
Dust in Your Images
Like molds, dust affects image quality. Seeing a faint speck of dust in your shots is quite normal, some will choose to remove it, others wont. But seeing one or two prominent ones, like those that are thread-like in nature, can be very annoying. Just image what dozens of those could do.
The first way to see dust is to observe floating elements in your shots. If it’s in all your photos showing in the same spot, then you have dust that needs to be removed. Another way to check for dust is by shooting a white surface in a place where there is enough light. Shooting against a cloudless sky away from the sun is also an option. Take some shots using these settings: ISO 100 (or lowest possible number), Aperture Priority, Matrix Metering mode, Exposure compensation 0, Aperture f/22. Some like doing this with everything blurred out so make sure to disable Auto-Focus and set your lens out of focus. You should also test for dust using your longest focal length set to infinity. For other camera types unable to choose these settings, just try shooting on a white surface.
Sample test done to check for blur. Photo by mightyohm
If there is any dirt affecting your shots, it will show up in the images. It is best to view it in your computer although sometimes you can see it when you zoom in the image using your camera.
Another way is to use Lightroom 5’s spot detection tool.
Checking for Dust Location
Again, dust can either be in the lens, viewfinder, sensor, or mirror. If you did the above test, you can determine where the dust is located. When dust shows up after doing the test, the dust is either in the lens or the sensor. Blurry dark spots are a sign of dust either in the sensor or lens. Larger spots would normally mean the dust is in the lens while smaller ones are dust accumulating in the sensor. Sharp prominent spots can also be seen and are usually dust on the sensor.
Dust in the lens can be in four places – outside the front element glass, outside the back element, in between the front elements, and in between the back elements.
Dust in the front and back elements are easy to remove. You can do it on your own with the right tools. You can clean it using an air blower, lens brush, carbonized lens pen, and microfiber cloth. For instructions on how to use most of these tools, read this article from BH photo on how to clean your lenses and filters properly. I personally use a Lenspen to remove dust since it also takes care of fingerprint smudges. It has served me well for a number of years.
If dust is inside your lens in between glasses, you can follow these instructions in this article on removing dust inside the lens.
Dirt inside a lens. Photo by Ian Miranda
If all else fails or if you don’t have any capability to clean the insides of your lens, then it is best it is best to contact the lens manufacturer for cleaning service if it’s included in your warranty, otherwise take it to a camera shop where you can have it cleaned. Some have attempted to clean their lenses using a vacuum cleaner. Its a crazy idea that I wouldn't recommend personally. But if you're adventurous, let me know your experience.
The first thing you should try to do if dust is in your sensor is to remove it using your camera’s automatic sensor cleaning option. DSLR and Mirrorless camera manufacturers have included this feature almost half a decade ago. If you have this feature then sensor cleaning will only take you a few seconds by just going to the menu options of your camera and without having to open your DSLR. Some even allow you to do this automatically when you turn on your camera.
If your camera doesn’t have this feature, there are different tools you can use to clean your sensor. For the standard way, follow these instructions on how to safely clean your sensor. There are other tools out there in the market you can check out like the sensor gel stick and lens sensor vacuum. But like any other tool out there, since sensors are pretty sensitive, it is best to research further and use with caution.
Pec Pad CCD sensor cleaning kit. Photo by wstryder
Point and shoots and bridge cameras don’t give users access to the system’s sensor. For these units bring the camera in for service. For DSLR and mirrorless users who wouldn’t want to do it on their own, you can do the same.
Mirror and Viewfinder Dust
With DSLRs, it is possible to see dust in your viewfinder and not in your shots. Essentially if you have dust in the sensor, it means, you won't see it in your viewfinder. When dust is in the viewfinder or the mirror inside your camera, the best way to clean it is with a rocket blower by blowing the dust off. It’s the same air blower used to clean the sensor. If this doesn't work then the only other solution is to bring it in for cleaning.
A rocket blower. Photo by Keith Williamson
Mirrorless cameras don’t have this problem since these cameras use digital viewfinders, which is essentially the unit’s sensor.
For other camera types the only solution is also to bring it in for cleaning.
Further Resources on Camera Cleaning