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Camera Care
What good is having a top-end camera if you don't look after it. What good is having a super high quality piece of glass (that's photographer speak for lens) if you let dust and fingerprints get all over the front of it.
There's nothing worse than being stuck out in the field with your camera (taking pictures of grass I guess) and finding you've got specs of dust (or maybe pollen) on the lens. For the sake of a few pounds/dollars/euros/yen (OK maybe quite a lot of yen) you can have everything you need to remedy the problem.
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So first of all we have the lens cleaning cloth. Make sure you buy one that is not going to deposit more dust on the lens than you had to start with. Ideally you should buy a good quality "micro fibre" cloth for best results. These are available for next to nothing from photography stores, or even your local optician.
Another way of removing dust from the camera body and lens is a blower brush (the green one in the pictue) or plain blower (i.e. without the brush, sometimes called a rocket blower or hurricane blower). |
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The brush is fine for the camera body, but we prefer to use just a plain blower on any of the glass parts of a lens. You can also use a blower on the main reflex mirror insider a DSLR - just start of blowing gently to see if that clears it first.
Be very careful when cleaning the mirror or focusing screen in your camera. While these can easily gather dust this dust will not affect the final image and both the mirror and focusing screen can be easily damaged by contact. The mirror silvering is only a thin coating and can easily be rubbed off by brushes and cloths.
Dirt on the Sensor
A much trickier problem is when dust gets on the image sensor. This is not a problem that affects compact or fixed lens cameras so much, but is a fact of life for SLR users, especially if you change the lens frequently. Many modern DSLR cameras come with sensor cleaning technology built in. These work by effectively shaking the sensor (well usually a filter in front of the sensor) in an attempt to dislodge the dust. Usually this will happen for about 1 second when the camera is first turned on.
However sensor cleaning systems don't always work - sometimes you get a stubborn little bugger that just won't shift. So how can you tell if you have dust on the image sensor? - First and foremost you may notice it on your images (especially in shots with a lots of sky in when using a narrow aperture).
Here's a test to check for dust:
1. First select a longish telephoto lens (or zoom lens set to the longest focal length).
2. Now select manual focus and set the focus to it's closest focusing distance.
3. Select aperture priority mode and close the aperture down to its smallest (i.e. the highest number - often around f/22 to f/32). The shutter speed will be slow but don't worry about this and it will not impact on this method.
4. Take a photograph of a white wall or white piece of paper.
5. Now look at the image on your computer at 1:1 (actual pixels) zoom level. If there is any dust on the sensor, you will see this as dark grey or black dots on the image (which appears in exactly the same place on every picture that you take).
Cleaning the Sensor
DO NOT (under any circumstances) use a blower brush on the sensor. You can use a plain non-contact blower such as the Giottos Rocket Air Blower which is designed to give a strong blast of air and claims even to be able to remove statically charged particles. DO NOT use cans of compressed air as the very high pressure can also damage the sensor and they often give off particles of super cold moisture that can damage your sensor.
There are two problems with using a blower bulb. First there is often dust that they just won't shift. Secondly blowing air into the camera can also mean blowing more dust into the camera so even when dust is removed from the sensor it can be replaced by other dust on a different part of the sensor. Regardless, we would recommend the Rocket Blower type method as your first angle of attack when trying to remove dust from your sensor.
If that doesn't work, either have it cleaned professionally, or buy a special sensor cleaning kit.
If you are not careful when cleaning the sensor yourself you risk scratching the sensor glass or damaging to the shutter.
To get at the sensor, you must first lock the mirror up (you will most likely find this is one of the cameras custom functions - consult your manual). You then need to open the shutter to reveal the sensor. If the shutter blades should close while you are trying to clean the sensor, you will certainly cause significant damage to the camera.
If your battery is fully charged and you use your camera's sensor cleaning mode this should not be an issue. Cameras can hold their shutter open for hours with a fully charged battery so before cleaning your sensor make sure you have a fully charged battery.
Most DSLRs have a sensor cleaning mode that hold the shutter open until the camera is turned off (or loses power).
There are a number of options (and associated products available) when it comes to cleaning your sensor. First, it is worth pointing out that you are not actually cleaning the sensor at all, you are cleaning a piece of glass that sits directly on top of the sensor and if you are careful and follw the instructions provided with the cleaning equipment all should be quite simple and trouble free.
The options available come down to two basic mechanisms: Dry or Wet.
Dry cleaning your sensor usually involves using a dedicated sensor brush such as Visible Dust's Arctic Butterfly. This device has an electronic brush head that is used to create a static charge on the bristles to attract dust from the sensor glass. You simply charge it up and gently brush it across your sensor.
There are also sticky pads available that are pressed against the sensor to grab dust such as the Dust Aid or SpeckGrabber products.
As mentioned already, you can also use a blower bulb (not blower brush) such as a Rocket Blower.
Wet cleaning usually involves the use of a special swab with a couple of drops of sensor cleaning fluid applied. The swab is gently moved across the surface of the sensor to clean the dust off. Where dry cleaning fails this method is usually successful. This is a very common and effective method of sensor cleaning.
With this method it is very important only to use the cleaning swab once. Each swab will come individually wrapped to avoid contamination and using one multiple times could result in grit scratching your sensor - a very expensive repair.
You also need to be aware which sensor cleaning fluid is suitable for your sensor. Different sensors have slightly different chemical coatings. The fluid manufacturer should be able to advise you which is most suitable for your camera. See here for Photographic Solutions list of cameras and appropriate fluids.
Finally there is another alternative wet cleaning method called sensor film which involves painting a liquid onto your sensor and removing it when it had dried into a gel.
Whichever option you choose only touch your sensor with something that was designed explicitly for that purpose.
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NOTE: Canon (and presumably some other DSLR manufacturers) only endorse two methods of sensor cleaning - one is the blower method (the one without the brush) and the other is to send the camera back to Canon for cleaning (at your expense).
If you decide to use a dedicated sensor cleaning kit - you do this at your own risk and you certainly risk voiding any warranty. |
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