So you bought a camera, charged it up, mounted a lens, and went out shooting... Did you ever stop to think, how in the hell does this thing work? Well, in every camera there is one magical little device called a sensor. This sensor is what captures light and turns it into an image, but it also determines the quality, resolution, depth of field, dynamic range, low-light performance, and even the camera's physical size.
Most cameras use one of two sensor types; CCD (Charged Coupling Devices) or CMOS (Complimentary Metal Oxide Semiconductor). The difference is actually pretty significant. CCD sensors have been used since digital cameras were created. They offer higher quality images with less noise when compared to CMOS sensors. However, CCD sensors come with a higher price due to the special manufacturing required so many manufacturers have switched to CMOS sensors to keep the price of their cameras down.
Fortunately, CMOS sensors are catching up to CCD and when they finally do I would imagine CCD sensors slowly disappearing. I am sure at this point the next generation sensor type will be developed.
Besides sensor types, there are many sensor sizes as well: Micro Four Thirds, APS-C, Full Frame, etc. The larger the sensor, the more light it can use to create an image. In other words: the larger the sensor, the better the image when compared to an equivalent smaller sensor. The only issue is when sensors grow in size, so does the camera and lenses.
Sensors smaller than Full Frame sensors (A sensor equal in size to 35mm film) have what is known as a crop factor. Let's say you are shooting with multiple cameras all with different sized sensors, but all with the same lens. With a Full Frame sensor what you see through the viewfinder is what you get. When it comes to smaller sensors the image starts getting cropped. It's like looking through a window: the smaller the window, the less of the overall view you see. This is why we are seeing more and more cameras released every year with full frame sensors.
So how many sensor sizes are there? The short answer: Many. Take a look at the image below and you'll see how crazy sensor sizes can get. The smaller sensors are typically what you see in phones while medium format sensors are in cameras that can cost over $30,000. Want to buy me one?
Any questions, concerns, or added information? Please let me know below!