The sensor is the core of your D-SLR and has a photodiode for each pixel that converts light signals into electrical signals for images to be produced. So if you have an 18 mega pixel D-SLR, your sensor has 18 x 106 photodiodes! How valuable, intricate and delicate a sensor is. Manufacturers typically place a low pass filter over the sensor that helps with eliminating unwanted patterns in images, but may also serve as a kind of protection for the sensor. Albeit, you have to be careful how you deal with it as it is still vulnerable. This is why there are specific instructions and precautions given by professionals and manufacturers of how to clean it. D-SLR manufacturers, including Canon, Nikon and Olympus among others, have infused sensor cleaning technology to vibrate those pesky dust particles off the sensor. It’s certain that dust will get on to your D-SLR’s sensor, and automated cleaningcan help, but it won’t be perfect. There are dust particles that will be more stubborn than others, and you may find them affecting image quality when they show up like annoying little black bugs. To fix this problem, you can clean the sensor yourself, carry your D-SLR to be cleaned by a professional or ship it off to your manufacturer to be cleaned.
Automatic Sensor Cleaning
A number of Canon EOS models has an automatic sensor cleaning unit that shakes dust from the front of the sensor. EOS models with the sensor cleaning unit are:
From a Canon EOS Manual:
“Whenever you set the power switch to <ON> or <OFF>, a sensor cleaning will be executed automatically. (A small sound may be heard.) During the sensor cleaning, the LCD monitor will display…"
If you’re not sure how to change the settings for Automatic Sensor Cleaning for your specific EOS, see: http://support-au.canon.com.au/contents/AU/EN/8201093300.html
Canon recommends that for best results to place your D-SLR on a flat surface before using the automatic sensor cleaning. Furthermore, you can disable automatic sensor cleaning, and use it when you desire. The sensor cleaning technology will get a fair amount of dust particles off the sensor, but there are particles that may remain. At this point, you can append the Dust Delete Data that involves using the Digital Photo Professional (DPP). Instructions of how to use this are stated in Canon EOS D-SLR manuals.
Cleaning a D-SLR sensor manually
If you are thinking of (manually) cleaning the sensor yourself, then the first thing to do is to find out what your D-SLR’s manufacturer states about sensor cleaning. So you’ll need to pop out your D-SLR manual to find out. Canon explicitly states that if using a sensor cleaning method that involves direct contact with the sensor, it is recommended to have it done at an official Canon service outlet. Using a rocket blower is the only method that Canon states to clean the sensor, but this is not to say that it restricts other methods. The ‘Wet Method’ is the most commonly used method to comprehensively clean D-SLR sensors of which a detailed and illustrated account can be followed on a previous canon5Dtips post: http://www.canon5dtips.com/on-the-web/diy-sensor-cleaning-tutorial/
But before you venture into manually cleaning your sensor, you’ll need to detach the lens and put your D-SLR into manual cleaning mode. On Canon EOS models, you’ll have to select [Sensor Cleaning] and then [Clean Manually]. There are precautions to take into consideration as well to ensure that no internal parts are damaged. Such damage can be disastrous — not to mention costly.
The following warning and precautions were adapted from a Canon EOS instruction manual. Though these instructions are Canon-based, they can be applied to other brands of D-SLRs.
Once you are clear with these preliminary instructions and precautions, you may continue with manually cleaning your D-SLR’s sensor.