Sensor Dust Is Evil. Here’s How to Banish It.
First, the good news:
If you have a point & shoot or a film camera, keep it clean and dust specks will never plague you.
And now the bad news: digital SLR sensors are magnets for dust.
Cleaning a digital sensor is nerve-wracking and risky, with enough methods, products, and gimmicks on the market to flummox a rocket scientist.
And that, dear friends, is why you have Photojojo.
We’re breaking it down right now: what works, what doesn’t, and whether the annoyance of having dust spots is worth the trouble of cleaning them. Let’s roll.
Photo credit: sgoralnick.
What’s the Problem?
“Cleaning the sensor” is a misnomer. The glass filter that protects the sensor is what gathers the dust and must be cleaned. While touching the filter isn’t as bad as touching the actual sensor, it’s still a delicate, easily-scratched piece of glass that costs a lot to replace.
Dust gets into your camera whenever you change lenses or caps, so dust accumulates over time. It mostly shows up as specks on areas of flat color, like a blue sky or white wall. Dust tends to show up at narrow apertures, so if you always shoot at f1.8, you’ll never notice it. Too much dust can cause your photos to look flat, even if you don’t see the individual specks.
If you want to see how much dust is on your sensor, set your camera to its narrowest aperture (f22 or thereabouts) and take a picture of a clear blue sky, white wall, or all-white computer screen. Then upload your photo and view it at actual pixel size. You’ll see fuzzy spots throughout the picture. If it’s hard to see the dust, follow this tutorial to make the dust pop out more.
How Big a Deal is It?
If you don’t notice the dust in your images, and you’re not shooting professionally, it’s no big deal. You can peacefully ignore it, and nobody will mind one bit.
If it bugs you, or if you sell photos professionally, then you’ll have to deal with it. Retouching the dust out of your photos can take forever, even with batch processing. And it can take up time and money if you send your camera to the repair shop or manufacturer to be cleaned.
The Quick & Dirty Rundown
To sum it all up, here’s what to do if you have dust on your sensor.
- #1: Most Safe Use the automatic sensor cleaning function, blow all the dust you can off the filter, and retouch or map out the remaining dust after the fact.
- #2: Less Safe, More Effective Use a very clean antistatic brush to sweep away the dust, and map out or retouch anything that’s left.
- #3: Less Safe, Most Effective Use a Sensor Swab to clean the filter, make sure there aren’t any streaks or dust left, and you’re done.
Read on for the pros and cons of each method, how to avoid dust in the first place, and loads of delicious nutritious information.
The Best Solution is Prevention
When changing lenses or body caps, do so in a non-windy, non-dusty place. Turn the camera off and point it towards the ground so gravity works with you to keep dust out.
Change lenses infrequently, and make sure the optics are free of dust before attaching the lens to the camera. Also clean your body cap before placing it on the camera.
Dusty environments like the desert or an abandoned building pose another problem. Don’t change lenses at all in dusty places. Choose one all-purpose lens and use it for the whole shoot. Once you get home, make sure the outside of the camera and lens is completely clean before changing lenses again.
Keep your camera bag clean, too. Vacuum it out periodically, and shake it upside down to get out any lint and bits of crud. No point trying to keep your camera clean if it knocks around in a dirty bag all day.
Think Hard Before Cleaning the Camera Yourself
Everything inside a digital camera is very delicate and very expensive to repair. We can’t be held responsible if you try any of these techniques and something goes wrong.
Be aware that for Canon, Nikon, Pentax or Sigma cameras, touching the filter in any way automatically voids your warranty.
Before doing anything about the dust in your camera, read your manual, re-read it, and then think very hard about everything that could possibly go wrong. If it seems like a bad idea, don’t do it.
How to Remove Dust
Here’s a rundown of the various ways to remove dust from your camera:
- Use the built-in cleaning system. Many cameras have a feature that vibrates the filter to dislodge bits of dust. This doesn’t work so well with stuck-on crud like pollen.
- Use the camera’s dust-deleting software. Some cameras have a feature that identifies dust that’s stuck to the filter and automatically maps it out of the picture when capturing an image.
- Remove it in post-processing. You can retouch the dust out of your pictures using image-editing software. This can be time-consuming, even if you use batch processes like those in Lightroom or Photoshop.
- Send it to the manufacturer. Having the manufacturer clean out your camera means there’s no chance of voiding your warranty. But it does involve shipping your camera, spending some money, and not being able to shoot while your camera’s in the shop.
- Use a hand-blower. This can dislodge some of the dust, but not stuck-on bits of pollen. DO NOT use compressed air or blow with your mouth.
- Use a brush. This method sweeps away more stubborn dust, but not the stuck-on crud. It can also leave smears of its own, and it voids your warranty if the manufacturer can tell you’ve touched the filter.
- Use a swab. When done right, this method removes dust and stuck-on crud. But it can also lead to smearing and/or scratching, and can definitely void your warranty.
“Hurricane” blowers have a bad reputation for blowing bits of rubber into the camera. Choose a blower with a plain tip (no fancy brush on the end).
DO NOT use compressed or canned air; the force can be too great, and if the liquid propellant gets in your camera you have a real problem. Don’t blow with your mouth either– spit particles will be really nasty to remove.
To clean your camera with a blower, put your camera into sensor cleaning mode (consult your manual for how to do this). Plug your camera in or make sure it’s 100% charged- if it turns off during cleaning, it could close on the blower and cause a lot of damage to the camera.
Blow into the camera with a decent amount of force, making absolutely sure the tip of the blower doesn’t touch the filter. Using a flashlight may help you see the dust better.
This will remove loose dust, but not the bits that are stuck on either by moisture or by a strong static charge. Do another test image (or use a special loupe) to see if you got all the dust off, and try again if you didn’t.
If after two tries, you haven’t gotten every speck, take a minute to think about how much dust you can live with. If you can deal with a small amount, just stop, relax, and forget about it. The methods from here on in get more precarious and potentially expensive.
Sensor brushes are more expensive than hand blowers, ranging from twenty to more than a hundred dollars. The specialized brush has an anti-static charge that helps dust release its static cling hold on the filter.
Brushes still won’t work on stuck-on crud like pollen, though. There’s also a chance that any oil or dirt on the brush can leave smears or scratches on the filter. Using a brush will void your warranty if the manufacturer can tell that you’ve touched the filter.
If you use a brush, never touch the bristles, clean it before each use, and don’t store it anywhere that it could get dusty or dirty.
Dust-Aid makes a single-use cleaning wand that eliminates the problem of accumulated dirt on the brush.
When done wrong, it can leaves streaks, smears, residue or scratches. Yikes!
There are lots of different swabs and cleaning solutions on the market, including plenty of DIY options.
Some manufacturers use them at their in-house facilities, and Photographic Solutions says they’re guaranteed not to damage your camera if used as directed. Fuji, Leica, and Kodak even allow you to use Sensor Swabs and Eclipse fluid to clean your sensor without voiding your warranty.
The drawback to Eclipse fluid is that it’s flammable and cannot be shipped by air. Ultra-Clean gets good reviews, and is a good alternative for traveling.
Other methods we’ve seen on the web include just about everything from Scotch tape, Q-tips and vacuum cleaners to ritualized human sacrifice. Most of them are really bad ideas that will almost certainly damage your camera (not to mention your sacrificial victim, who may come in handy later on).
Stick with methods and products that have been rigorously tested and have a solid guarantee. Learn how to use them properly and be very very careful.