An image sensor is a device that converts a visual image to an electric signal. If you have been reading the articles in this website by now you probably have realized that Digital SLR sensors play a major part in the
final output of a photo from a digital SLR camera in terms of quality, noise, sensitivity and increased latitude and all that matters.
If this is the first page you've opened in the website, don't worry because we are going to dedicate this article to explaining more about digital SLR sensors.
Let us first lay some foundation first, Digital SLR cameras are a similar to analog SLR cameras only that the digital ones are now made to function digitally and do not use a film to capture images. A Digital SLR is just a computerized version of the analog SLR camera that uses light sensor chips instead of film and digital memory cards.
The film component was replaced by an image sensor that is mounted on to where a film used to be. This is a light sensing CCD (chip) which is used to convert the incoming light rays into a digital picture. In addition the digital SLR camera has internal memory and other digital components that are not necessary our point of interest for now.
So what makes the digital SLR camera better is that the size of the surface where an image is captured can vary to allow for different quality needs whereas with analog cameras this space was fixed to only accommodate the 24 by 36 mm film. These sensors come in various sizes with medium format being the largest ones. These largeness means better quality but also high price. In essence, the digital SLR camera sensors are much larger than the sensors found in a point and shoot digital camera and they have higher a resolution, which all translates to a clearer and crispier image. So a 10Mega pixel point and shoot camera actually has lower image resolution than a 5 mega pixel Digital SLR camera with a larger sensor.
Some of the most popular digital SLR sensor types available today include the, CCD (charged-coupled device). This is currently the most popular type of digital SLR sensor. They are designed for speed and for good image quality. Popularity obviously translates to high price. Almost all digital SLR camera manufacturers offer at least one model with a CCD digital SLR sensor so you can review each one of them for price and make a pick. Another type is the CMOS (complementary metal-oxide semiconductor) digital SLR sensor, which can be a bit cheaper and uses less power but they come in large sizes.
In ter ms of size we mentioned earlier that the digital SLR sensors are bigger than the point and shoot digital cameras. Olympus and Kodak created the Four Thirds used for the Four Thirds Format. Its dimension is 13.5 by 18mm. You can get these in a camera like the Panasonic Lumix DMC-L1. There is also those built with the size of the APS-C or APS-H film formats like the Canon EOS Digital Rebel XT1 and the Sony Alpha DSLR A100. It is important to note the sizes for these sensors vary; they can range from 14 by 21mm to 19.1 mm. Then there is the full-frame sensor which is the same size as a standard film i.e. 35mm or 24mm by 36mm. These are bigger and expensive to manufacture.
Let us end the article by bringing up a problem that you may encounter while using a digital SLR camera. This is the digital SLR sensor dust problem. This is caused by the removable lens - when you remove the lens you expose the digital SLR sensor to dust. Once dust enters into the sensor you are definitely going to see it in the images taken with that camera afterwards. This can really get frustrating.
In order to limit dust from affecting your digital SLR sensors, avoid changing them in dusty conditions and when you do, do it fast. This way you can be assured that the digital SLR sensor is not fully exposed to any dust particles when changing you lens. Some DSLRs offer another solution whereby the sensors vibrate each time you switch the camera on or off. This way they remove any dust particles stuck on the sensors but not many DSLRs have this capability.
If it happens that you get some dust to your sensors, do not attempt to clean it yourself especially if you are not an expect. Simply take the camera to a service shop where professionals can get it cleaned. What's a few dollars to damaging the most important component of your digital SLR.
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