Digital Sensor Sizes

Many of us started photography in the age of 35mm film cameras. So as the digital age has come upon us we have had to adjust our thinking to the fact that the sensors in digital cameras come in many sizes. To make this adjustment the industry standard has continued to be the 35mm film standard. So in sensor terms a "full frame" sensor is the same size as 35mm film. There are many things to keep in mind when considering sensor sizes. But two are especially important. First of all the larger the sensor the better overall quality in can produce in the final picture. Not all sensors are created equal, but this is an important rule of thumb. The typical "point-and-shoot" camera has a very small sensor (see illustration below). Professional and advanced amateur cameras have larger sensors, often the APC sizes as shown on the chart. Larger sensors can take in more information from light, and record a larger range of colors and tones. They often produce better results in low light. They can retain more detail. Of course all of this comes at a cost. Larger sensor cameras are more expensive, with full frame cameras being especially expensive.
There is another important issue concerning sensor sizes. Most lens makers continue to label lenses like they did in the days of 35mm film (with some exceptions). But these lenses perform differently depending on the sensor in the camera. For example, a lens labelled 50mm performs as a so-called "normal" lens on a full frame sensor or on 35mm film. However, on an APC size sensor (the typical Nikon or Canon DSLR) its focal length is effectively 75mm, thus it has become a short telephoto lens. The smaller the sensor the more this effect is magnified. There are other sensor issues relevant to camera performance, but this should serve as a basic introduction.

Note: these are not actual size, but relative sizes. Do you have questions or feedback? Email me at dansphotophile@hotmail.com, or visit my website at www.danwrayphoto.com