Understanding how to clean sensor dust

- The great thing about a camera with interchangeable lenses is that, you can change the lenses, so you've got a lot of flexibility about lens choice for the focal lengths that you want, zooms versus prime, image quality, weight, size, all that stuff. One of the downsides to a camera with interchangeable lenses is that you can take the lens off, and when you do that, there is a chance that dust will get inside the sensor and leave spots all over your image. Spots that look like these. This is one particular kind of dust, there are many kinds, and we're gonna talk about that. But if you're seeing these kinds of spots on your images, there's a very good chance you've got a dust problem.

A lot of people think, "Oh, my lens needs to be cleaned." Most of the time, if there's something on the end of your lens, you're focusing past it and it's not visible. One of the ways you can easily tell if you've got a sensor dust problem is if the dust is showing up in the exact same spot of the frame very time. That means little bits of something have actually gotten inside the camera and stuck themselves to the front of your sensor, and at that point, you need to get your sensor cleaned. Or, you need to clean it yourself, and that's what we're gonna talk about here for a while. Before we get to cleaning the sensor, let's talk about what you can do about the dust that's on the images you've already taken.

Obviously, this stuff can be taken out in an image editor, Photoshop's Spot Healing Brush tool is a great, really quick way for getting rid of little spots like this. Both Lightroom and Camera Raw also have very good spot-removal tools, and what's cool about those tools is you can set them on one image, and then copy and paste them to other images, and batch-clean your files that way. Some cameras can take a dust-map. Canon cameras call this "Dust Delete Data", Nikon cameras, I think call it a "Dust Map".

What that is, is basically a picture of the dust that's on the sensor. If you use Canon and Nikon's image processing software, it can read this dust map data to automatically clone the dust of your images. That's another way to deal with dust that has gotten onto your final shots. What I want to talk about now, is actually addressing the problem at the source and getting the sensor clean. Static electricity is necessary for your image sensor to work. Every time you turn the camera on, before you take a shot, in between every shot, the camera charges the surface of the sensor with static, or with an electrical charge.

That's part of how a CMOS or CCD sensor works. The problem is, that status attracts dust, so if there's anything loose in the sensor chamber, dust from the outside world, dust from particulate matter flaking off of the internal components of the camera, or small blobs of grease and liquids that are used for lubricants inside the camera. All of that stuff could be floating around in there, and the static charge can mean that it's gonna just adhere right to the sensor. There are a couple of different kinds of dust. There's just the straight, particulate matter that's stuck there that you can blow away or brush off.

Or, there are liquids, and those either come, again, from inside the camera, it's own lubricants and things, or from the outside if you try to clean your sensor by blowing into the camera or something like that. Those can get in there, and sometimes they can combine. You could have a piece of liquid with some dust in it. These things all require different types of cleaning. I'm gonna start with the simplest type of cleaning, which is, well actually, I'm gonna start by addressing the dust on this specific camera and let you see what we've got here. You've seen those images. One way to tell if you've got dust and where it is is to do a very simple test with a white wall.

Set your camera to f/22, de-focus it, and take a shot of the wall. When you bring it into your computer, you should be able to very easily see the dust, as you can here. That's nice, except I gotta do some thinking to figure out what I'm cleaning. Which corner in the image equates to which corner of the sensor, so that can be a little bit confusing if there's a particular area that I feel really needs work. Another way to go is with a sensor-cleaning loupe. This is a product from Visible Dust, visibledust.com.

This is their Quasar PLUS Sensor Loupe. It is a very beefy magnifying glass with built-in LEDs, and with it I can very easily examine my camera's sensor. First thing that happens when I take the lens off and I go to look, here, is I see a big mirror there. That's the mirror that makes the viewfinder work. I need to get that out of the way. Mirror lock-up will not do it because mirror lock-up leaves the shutter closed, so I can't actually see the sensor that's sitting behind it. Instead, I need to activate the actual sensor-cleaning mode, here.

When I do that, the mirror pops up, the shutter opens, and now the sensor is exposed. Now, I'm just gonna leave this open while I talk for a while, because this is Jacob's camera, not mine. The sensor itself is not directly exposed to the outside world. Sitting in front of it is a low-pass filter, that is a filter that's cutting out some infrared and doing some other things that are necessary for the sensor to be able to calculate color data and all that kind of stuff.

My sensor is actually protected from the outside world. Nevertheless, that filter is fragile, I don't want to just go poking things in there, I want to be careful. But also, the filter is coated with a special substance that conducts static away. It should be doing a pretty good job of keeping material off. Nevertheless, dust can get on there. With my sensor loupe on, I'm gonna look in here and oh my goodness, there's all sorts of things. There's dust, and missing car keys, and some other stuff. One of the things that's difficult when you are looking at the sensor like this, is that the surface of the sensor is kind of holographic.

It's got depth to it, and so sometimes it's hard for your eyes to focus on the surface. You will focus deep into the sensor and not see dust. As you pull the focus of your eyes back, you can see it. In this case, it's pretty easy, because there's just so much stuff on the sensor. Now, it's time to try to get rid of it. I'm gonna start that with a blower brush. I have two different blower brushes here. The idea with these is, I'm gonna blow some air in with the hope of dislodging that dust and having it fall out of the camera.

Before we get to these, I want you to notice what's not sitting on the table here, right now, and that is a can of compressed air. There's not even one in the building anywhere. If we could get them out of the county, we would, because you do not ever, ever, under any circumstances want to blow compressed air inside your camera. The reason for that is, the propellant in that can is a liquid, and if you're not careful, some of that liquid will fly out, and stick to your sensor, and then you have a wet-cleaning problem, you've got an actual stain of some kind.

You want to stick with a blower brush, I have two different options, here. I have a regular blower brush, and then I have a Visible Dust blower brush. They differ in a few different ways. This is just a straight bulb, here, and it puts out a blast of air, and it works very well. This one is quite a bit more sophisticated. The rubber that this is made out of generates a charge that dissipates the static on the surface of the sensor, so the very act of blowing this in here is possibly going to help the dust dislodge, because I'm neutralizing the charge on the sensor.

Also, this is not in-taking air from the front, it's taking air in from the back, so while it's in there and I'm blowing, I'm not blowing, stirring up a bunch of dust and then sucking it into here, only to have it blow back out again. This is the Visible Dust Zeeion anti-static blower. This is a much more sophisticated set of materials, basically. What I'm gonna do is, hold the camera upside down, because as I blow the dust around, I want it to fall out. I'm gonna just stick this up here, I'm gonna be careful not to go in so far that I'm bumping into that filter, and I'm gonna blow.

Now, notice I'm not squeezing very often. Couple of reasons, it takes a while for this to slurp in more air but also, if I do that, what I'm doing is causing the air to move around more. As the molecules bump into each other, it's possible that they will build up a static charge again. I'm just being careful to manage the static in this situation as much as possible. I'm kind of pointing at the corners. I'm paying attention to where I thought I saw dust, and I'm trying to target some dust in there, I mean, some air in there.

Alright, let's get the Loupe back on. Okay, some is gone, some is not. some of it's very reflective, also, which is interesting. There are some things you can do to prevent getting into this situation in the first place. One of them is being very careful where you change lenses. If you're outside on a windy day, be sure you're doing your lens swap in a sheltered situation, if that's possible. Another thing is, when you take the cap off the camera and off the end of the lens, don't stick it in your pocket, because that's full of dust, and whatnot.

That will get all dusty, you'll put it back on your lens, your lens will then transfer that into the sensor chamber. Alright, we got rid of some more, but I also feel like all I've done is move some of the dust that's in there around. We'll give this one more try. When I'm done with this, all I do is power the camera off, that cancels cleaning mode, the mirror will come back down and the shutter will close. You want to be sure you're doing this with a fully-charged battery, or with it plugged into the wall, because you don't want the mirror to come down while the nozzle of that thing is inside there.

If you do, the mechanism could get jammed up and could break. No, I've gotten rid of some, but there's still a lot in there. It just, every time I clean my sensor, it makes me, from that point on, very diligent about being more cautious about sensor dust. Most of the dust that comes into your sensor chamber is transferred there by the end of your lens, so again, be very, very careful with keeping your lenses clean, and keeping the caps clean, because that's all gonna be transferred to your sensor, and that's how things are going to get dustier.

From here would be additional steps. Wiping with a special brush. If that doesn't work, going to a wet solution. This is not the end of the road, there are ways of cleaning this sensor. In the meantime, I know how to get my images clean, and I'm gonna be very careful about making sure that no more dust gets inside my camera.