If you snap photos with your DSLR long enough, it’s bound to happen: dust will find its way onto your camera’s sensor and begin marring your beautiful photos. Read on as we walk you through a safe multi-step process to return your camera sensor to a factory floor shine.
Why Do I Want to Do This?
The inside of a digital camera is a veritable dust magnet. Every time you swap lenses you’re effectively inviting particles of dust to swirl right in and stick, courtesy of the electrostatic charge the interior of the camera carries, to the mirror, body chamber, and the camera’s sensor. While it’s less than ideal to have dust anywhere inside the body of the camera, the only time it becomes a real nuisance is when it clings to the sensor and appears in your photos.
Once the dust is on the sensor it rarely moves; the only way to banish the gray dots and black spots from your future pictures is to clean the sensor. Most people are completely freaked out by the idea of undertaking such a task, believing that the sensor is far too delicate for mere mortals to touch. We assure you that cleaning your camera’s sensor is not only easy and almost entirely risk free (when done patiently and with the proper tools, of course), but that it’s downright economical.
A typical professional in-factory or certified-shop cleaning usually runs around $75 (plus an additional $25 or so in shipping costs if you have to send it out). $75-100 will get you enough supplies that you can routinely clean your entire stable of digital cameras for years before restocking.
Over the lifetime of the camera you’ll save enough by performing your own cleanings that you’ll effectively have purchased the camera with the savings.
What Do I Need?
The following tutorial is divided into segments starting with the least aggressive/risky cleaning technique (no contact at all with the sensor) and moving towards the more aggressive techniques (dry and wet contact with the sensor). We recommend purchasing all the tools at once so you’re ready to follow along with the entire tutorial as needed (depending on how dirty your sensor is).
- 1 LED-illuminated Sensor Loupe (~$40)
- 1 Giottos Rocket Air Blaster (~$8)
- 1 Electrostatic DSLR Sensor Cleaning Brush (~$28)
- 1 Sensor Swab Kit (~$18)
Before we continue, we need to highlight one very important detail. You need to adjust your purchases based on the type of camera you have. We’ll be cleaning a Nikon D80 which has a fairly standard APS-C sized sensor like many consumer DSLRs. If you’re cleaning a camera with a full-frame sensor (such as the Nikon D600 or the Canon EOS 6D) you’ll need to buy a larger electrostatic brush and swab kit suitable for a a full-frame sensor.
A very stern caution before we continue: Buy the right tools. The biggest risk you undertake in cleaning your camera is not that you’ll damage it with proper technique and tools (the filter glass they put over the sensor is quite durable), but that you’ll damage it by using improper tools.
You must not use canned air in place of a the Rocket Air Blaster we recommend. You’ll coat your sensor will all the nasty lubricants and propellants that are in the can of compressed air, and the resulting mess will be agony to clean up. The Rocket Air Blaster we recommend is specifically designed for cleaning electronics and has a filter on the air intake so that you’re blasting clean and contaminant free air out of the nozzle.
By the same token, you can’t just pick up any old art brush and start cleaning your sensor. The brush we recommend (and other brushes like it, designed for DSLR sensor cleaning) is specifically designed to be pure, uncoated, and intended to touch the surface of the sensor.
The same thing goes for the sensor swabs and cleaning fluid. You can’t just grab a box of Q-tips and a bottle of denatured alcohol from the hardware store and achieve the same effect. The swabs and the cleaning fluid are manufactured specifically to be as contaminant free as possible, again, to avoid putting additional contaminants and impurities on the sensor.
In other words, it’s fine to choose to buy the $30 sensor brush instead of the $100 sensor brush, but don’t even think about attempting this with the $2 art supply store brush that happens to look close-enough to the sensor brush we recommended.
Taking a Reference Photo
The very first step in the cleaning process is to take a simple reference photo in order to see how the dust on the sensor is impacting your photos.
It’s difficult to pick out all the bits of dust when you’re taking a regular photograph, as the natural distribution of light and dark elements in a typical photo (shadows, clothing, texture of hair, etc.) will hide all but the most painfully obvious imperfections.
The best way to see the sensor dust via photo reference is to take a photograph of a neutral background (such as a white or light gray wall or the blue sky on a perfectly clear day) with the aperture of the lens closed down as tightly as your lens will allow. This means you want to set your camera to aperture priority mode and adjust the aperture number as high as it will go (you’ll remember from our Depth of Field tutorial that the higher the f-number the smaller the physical opening of the aperture). If you can go to f/22 or higher, that would be ideal.
Even more ideal would be to use a pinhole lens, as pinhole lenses routinely have f-numbers that exceed f/100. The reason we want as small an aperture as possible is that the smaller the aperture of the lens the more directly the light hits the sensor (and thus causes each spec of dust to cast a harder shadow on the sensor’s surface). A spec of dust that’s barely noticeable at f/2 looks like a hole burned right into the photo at f/22+.
Don’t worry if you need to use a longer exposure time to get a nice bright image. We don’t care if the background is in focus (and would prefer that it isn’t perfectly sharp, actually). The specs of dust, by default of being physically attached to the sensor, will stay crisp and unblurred.
Once you’ve snapped the photo, feel free to adjust the brightness/contrast in your favorite photo editing application. The more the dark specs of dust stand out in your reference photo the better.
Be sure to zoom in and really look at the reference image. The photo we have at the beginning of this section is the entire frame reduced to a much smaller size (and even then you can see how absolutely filthy this hard working camera’s sensor is). Let’s zoom in on the upper-middle frame:
You can see the really big and irregular pieces of dust (like the huge black one at the top). Those bits of dust are likely so large they’re visible to the naked eye looking into the camera. The little ones, however, that just leave little circular shadows that look vaguely like blood cells, are the tiny ones we’ll need to clean carefully to remove (and inspect a reference photo or two later to ensure we did in fact remove them).
Preparing for the Initial Cleaning
Before we get down to the business of actually opening up the camera, there are a few important preliminary steps we need to go through in order to make the cleaning process safe, effective, and frustration free.
Completely charge the camera battery. The majority of digital cameras will not allow you to perform the steps necessary for manual cleaning (such as locking the reflex mirror in the up position) unless the camera has well charged battery.
Clean off the exterior of your camera. If the body of your camera is dusty/linty/dirty then there’s a significant chance you’ll introduce that dust and dirt while you’re working on cleaning the camera. It might seem painfully elementary, but take a moment to dust off the body of the camera. We find that a Q-tip or two dampened with the tip of the tongue or a drop of rubbing alcohol is a perfect tool for removing dust and lint from all the little curves and crannies around the body of the camera.
Clean your work space. Now that you’ve cleaned off the body of the camera, clean off your work space. Again, it seems like elementary advice, but if you’re working at your desk with a dusty monitor riser and messy keyboard, you’re just begging for that crud to migrate into your camera, onto your cleaning brush, or to otherwise end up where it doesn’t belong.
No-Contact Sensor Cleaning
There are two principle steps to the no-contact phase of the sensor cleaning process: engaging the dust reduction system and using the blower.
If your camera has a dust reduction system, engage it now. Not all cameras have a dust reduction system (the Nikon D80 we’re using for this tutorial, for example, does not), but if your camera does have one, it’s worth using. Look in the system menu for an entry like “Dust Reduction” or “Dust Removal”. Although each manufacturer uses a slightly different technique, the general idea is that the dust reduction system vibrates the protective glass filter over the camera’s sensor at a very high speed, which causes the particles of dust to shake off. It’s not a perfect system, but if your camera supports it, by all means use it.
Lock up the mirror. DSLR cameras, like the SLR cameras that proceeded them, use a mirror system to allow you to frame your photos through the actual lens. When the camera is not actively engaged in the process of taking the photo, you can look through the eyepiece and a system of mirrors shows you what the film/sensor will see through the lens. When you take the photo the mirror flips up and the light shines onto the film/sensor instead of onto the mirror and up to your eye.
In order to clean the sensor, we need to get the mirror out of the way. Go into your camera’s system menu and look for an entry like “Mirror Lockup” or “Sensor Cleaning”. Most cameras will give you additional instructions like to press the shutter button to lock the mirror up and to lower it down when you are done. We’re going to lock our mirror up now.
Examine the sensor with the loupe. Once the mirror is locked up, remove the lens. With the mirror out of the way, you’ll be able to see the sensor. Now is a perfect time to examine it with your sensor loupe:
Keeping in mind that the lens produces an inverted image which the camera then flips for us, look at the bottom of the sensor in the photo above. That very visible white chunk of dust is the huge black spot that appeared in the upper-middle portion of our first reference photo.
Blow the dust off with the air blaster. After examining the sensor, carefully pick the camera up and invert it. Hold the camera firmly in one hand so that the opening of the camera body is pointed towards the floor. Pick up the air blaster in your other hand and vigorously blast air around the chamber of the camera and at the sensor. Really the only way to go wrong in this portion of the tutorial is to either drop your camera or slam the nozzle of the air blaster into the camera sensor. As long as you take care to hold the camera firmly and not smack the nozzle into the sensor you’ll be fine. Blast away and let the dust drift down and out of the camera body.
Let’s examine the sensor with the loupe again:
Even though the 10x loupe can’t show us every mote of dust on the sensor, it’s pretty obvious that the largest bits of dust have been completely removed. That hulking monster of a dust bunny that was hanging out on the edge of the frame, for example, is long gone.
We’re going to pop our lens back on and take another reference photo. You don’t have to take reference photos between every step (you can clean from the first to last technique straight through), but we’re documenting every step to show you the major and minor changes on the sensor between techniques.
Compared to our first shot, that’s a remarkable difference. Yes there are still some fuzzy spots and a few legitimately dark spots, but just blasting the sensor with air took care of the really big junk. Let’s look at a close up of the upper frame in the same spot we did last time:
That’s pretty fantastic. It’s nice to zoom in on the photo and not have it look like moths had eaten holes in it.
Now that we’ve done the no contact cleaning, let’s move on to dry cleaning the surface with the electrostatic brush.
Dry Cleaning Your DSLR Sensor
In the last section of the tutorial, we used filtered air to blast the loose bits of dust off the sensor glass. Now we’re going to use an electrostatic brush to pick up even more off the glass.
Before we proceed, there is really only one big caution for this portion of the tutorial. When using the sensor brush, your goal is to stay completely on the sensor and to not touching the surrounding area in the camera. Some of the parts within the chamber have lubricating oil/grease on them (a very tiny amount, but still present) and it’s easy to smear it onto the glass of the sensor. It’s not the end of the world (and it won’t ruin your camera by any means), but it is a huge pain to clean off using the swabs later on. Work with a patient and steady hand to avoid making a mess. As long as you take care to aim the brush towards the sensor and avoid touching the walls of the chamber, you should have no problems at all.
Just like in the previous section, we need to lock up the mirror and remove the lens to access the sensor.
Preparing the brush. The brush is self-charging; when the bristles rub together they generate the static charge necessary to lift the particles of dust off the sensor. In order to charge it, use the air blaster to vigorously ruffle the bristles. Do not blow on it or touch the bristles! If you blow on it, touch it, or otherwise mess with the bristles you’ll transfer oil and contaminants. The brush, once removed from it’s storage tube, should touch nothing but the camera sensor.
Cleaning the sensor with the brush. Charge the brush with the blaster and carefully lower it down onto the sensor moving from one side of the sensor to the other in a single motion. Remove the brush from the chamber. It’s important to not dab the brush around like you’re stippling paint or to drag it around; each time you use the brush the charge dissipates after the first contact to be sure to make one clean motion and then remove the brush from the chamber.
Blast the bristles again to blow away the debris it picked up and to recharge it. Repeat the process, examining the sensor with the sensor loupe to detect any changes in the visible dust particles.
Feel free to mix in a little air blast to the chamber along with using the air blaster to recharge the brush. Most times, the sensor brush will loosen dust particles that it may not catch with that pass (or the subsequent one).
After you’ve performed several passes on the sensor and you can’t see any visible dust with the sensor loupe (or that visible dust refuses to budge despite multiple attempts with the brush and air blaster), it’s time to take another reference photo. We saw two very small specs with our sensor loupe, but there’s no way to tell if they’ll appear in photos without actually taking a reference photo.
Obviously, this is the full camera frame shrunk down to a small image, but it’s clear the sensor’s condition is radically cleaner than when we started. Let’s zoom in on that same section we’ve been looking at all along and see what we find:
Unlike in in the previous two close-ups where the dust was painfully obvious, now we feel obliged to provide reference arrows. Those two tiny specs, the only visible dust we could find via the sensor loupe after using the electrostatic brush, are all that remains of the enormous pile of crud that was on our D80′s sensor.
This is the point in the cleaning process where you may decide, based on the results of the reference photo, to consider the job done if there is no or next to no visible dust in your photo.
Since we’re perfectionists (and we’d be awful tutorial writers if we just threw our hands up and went “Ehh, good enough!”), we’re going to forge ahead and finish the process with a wet cleaning to smite the last of the dust mites.
Wet Cleaning Your DSLR Sensor
Wet cleaning is exactly what it sounds like: using fluid to clean the surface of your camera’s sensor. There are a few rules to work by here (and they’ll sound a lot like our warning at the beginning of the tutorial): only use swabs and cleaning fluid designed for camera sensors, and less is more. We don’t want to give the camera a bath, we want to give it an effective but barely damp wipe.
Prepare your materials. If you bought a kit with both lens cleaning pads and sensor swabs, make sure you’re using the sensor swabs for this portion of the tutorial. Sensor swabs, as seen in the photo above, are like little tiny plastic spatulas wrapped in a special cleaning cloth.
Moisten the swab. Remove a single sensor swab from its protective bag. Drip a drop or two of cleaning fluid into the swab. You want just enough fluid to dampen the cloth, but not enough for it to drip into the camera. If you applied too much, just wait about twenty seconds–the cleaning fluid is a very pure and highly concentrated alcohol, so it will evaporate quickly.
Swab the sensor. Using the same kind of patience and steady movement you used with the electrostatic brush, swab from one side of the sensor to the other with firm pressure. You don’t need to wiggle the swab about; the sensor swab is the exact width of the sensor.
Lift the swab out of the chamber, rotate it to the clean side, and repeat the motion in the opposite direction. In other words, if you went left to right with side A, go right to left with side B.
Do not reuse the swab once you have used each side of it once. Dispose of the swab and repeat the process as necessary with additional swabs. (If you’re trying to be economical with your supplies but not necessarily your time, you can take reference photos between swabbing sessions.)
Let’s take a look at the reference photo we snapped after the first swabbing:
We’re not even going to show you the full frame one, but instead we’re going to jump right into the zoomed in one. Why? Because there’s nothing to see! After blowing, brushing, and finally swabbing the sensor, there isn’t a visible point of dust on the entire sensor.
Not only did the sensor look absolutely sparkling through the sensor loupe, but the reference photo proves that it’s as clean as it was the day it was made (if not cleaner).
That’s all there is to it! Although cleaning your DSLR camera’s sensor seems like an enormously intimidating task that would most certainly end in tears and the purchase of a new camera, it’s actually a pretty straight forward and safe bit of routine maintenance. We spent less on all our supplies than we would have spent to ship our camera off to Nikon for a professional cleaning and the materials like the sensor loupe and brush will last us the life of the camera and beyond.
Jason Fitzpatrick is warranty-voiding DIYer and all around geek. When he's not documenting mods and hacks he's doing his best to make sure a generation of college students graduate knowing they should put their pants on one leg at a time and go on to greatness, just like Bruce Dickinson. You can follow him on Google+ if you'd like.
- Published 05/6/13