The size of a camera sensor will have a big impact on the quality of your pictures. The lens gathers light and directs it towards the sensor, and the sensor records the light to create the image.
Large sensor produces better images
All things being equal, a larger sensor will receive more light than a smaller one, and produce better images. This is especially important in low light photography.
When light levels are low, a smaller sensor will generate a higher amount of noise, which will decrease the quality of the images. This is why the best low-light setups include a camera with a large sensor, such as a digital single lens reflex camera, and a lens with a large aperture.
Compact digital camera sensors
In the compact world, most sensors are generally around the same size. Sensor size for compacts is calculated by measuring the sensors diagonally. The most common sizes are 1/2.5 (0.4) and 1/2.3 (0.43) inches. Pretty small by all accounts.
Backside-illuminated CMOS sensors, such as those found in the Canon SD4000, are small but generally do better in low light than CCD sensors. They also provide faster continuous shooting speeds.
Larger compact camera sensors
Manufacturers have started including larger sensors in some of their compacts. For instance, Canon’s s95 camera has a 1/1.7 (0.58) niches sensor. This represents a total area 37% larger than most comparable models, and yields much better low light pictures. Compact cameras like the Panasonic LX5 also sport larger sensors. [Related article: Low light pocket cameras]
One thing to keep in mind is that the size of each individual pixel is what will truly define the performances of the sensor. In other words, more pixels over the same area means that noise levels will increase, because each individual pixel will receive less light.
The sensor in a typical digital single lens reflex camera is many, many times larger than the sensors found in compacts. This means that DSLRs are much better at taking low-light pictures with low noise. But even in the DSLR world, there are differences between sensors.
The larger sensors are called “full-frame” and are found in some higher-end, professional bodies. The size of these sensors is equal to that of 35 mm film, with a 1.7 inches long diagonal.
The vast majority of DSLRs have sensors slightly smaller called APS, with a 1.18 inches diagonal (48% of the area of the full frame sensor). The use of the APS sensor allows smaller lenses to be designed while still preserving most of the optical performances of the sensor.
Another sensor size used in DSLRs is called Four Thirds (0.85 inches diagonal). This system, while being slightly less efficient in low light, makes possible the use of extremely small lenses. This sensor size is used in the “Micro Four Thirds” system, which is a bridge between compacts and DSLRs.
Visit our Amazon shop for a list of compact digital cameras with larger sensors