Sunday, October 3, 2010
The types of digital cameras
The most basic digital cameras are those built into cell phone. Many do not even think about their phone being a camera, but some of the newer phones actually produce quite good image quality at five mega-pixels or more. The biggest problem with phone-cameras from a photography standpoint is the total lack of control. ISO speed, color balance, lens aperture and shutter speed settings, file format of the image file and amount of compression used on the image file are all handled by the phone with no input from the photographer. For quick record shots to immediately send to a friend by e-mail or to post to Facebook or Flickr, they are adequate and obviously much better than nothing. For more serious photography they can also produce quite good images as long as their limits are known and worked within.
Next up the image-quality scale are the compact digital cameras. This type of camera has a built-in lens, often a zoom, a small image sensor with correspondingly tiny individual pixels and often lacks an optical viewfinder. Compact cameras cover a very wide range, from barely above cell-phone functional to nearly DSLR quality. The huge majority are in the middle of this range. They offer zoom lenses in the 3x to 6x range, some exposure control(compensation and/or aperture priority but often not full manual settings), often a choice of ISO speeds and usually include some sort of anti-shake mechanism. The best of the compacts also offer a hot shoe for more powerful flash, near DSLR-like control of settings and the choice of saving image files in RAW format for better image quality.
Compact cameras should produce image quality more than adequate for any on-line use and print publication at up to full page sizes. Careful attention to shooting techniques minimizing noise/grain and maximizing sharpness/detail will really pay quality dividends with these cameras. Images taken with my personal compact camera are used regularly to illustrate my on-line real estate column and web sites.
A new type of camera occupies the next rung of the ladder. A real name has not yet been decided but they are being called “compact interchangeable lens”, “micro four-thirds” or “electronic viewfinder interchangeable lens” cameras. They use a sensor much larger than most compacts but about half the size of most DSLR’s. Lacking optical viewfinders, they rely on built-in or accessory electronic viewfinders or just on the camera-back LCD. Because there is no prism or reflex-mirror housing and a smaller sensor, these camera bodies can be made nearly as small as a compact camera with small, light-weight lenses to match. Because the sensors are much larger than those in compact cameras image quality can come close to matching that from DSLR’s. My feeling is this class of camera will really catch on with the public.
DSLR’s are the traditional 35mm film camera in digital form. Sensor sizes range from APS-C to full-frame 35mm, giving large individual pixels for optimum image quality even at higher ISO values. Bright, sharp optical viewfinders occupy the top of the cameras, with some also offering “live view” on the camera-back LCD(emulating compact cameras). All of the functions offered on traditional 35mm film cameras plus many more are available on almost every model. The result is a comparatively large and heavy camera body and accompanying lenses. In practical use, this type of camera is still the most versatile, offers the greatest choice of lenses, flashes and other accessories, and produces adequate image quality for up to 16”x20” prints or even larger.
The final type of digital camera is the “medium” format. Again, these are digital versions of the former film cameras. They are generally considered professional-only because of the high price of the bodies and lenses. Much larger and heavier than DSLR’s, usually only those needing extremely large prints or the ultimate of image quality even consider them.
My personal choice is a combination of camera types. I have a cell phone with a 5MP camera which works fine for a quick snap of a restaurant dish for an on-line review, to record dings/scratches on a rental car or to remember a house for sale. I use a compact camera for on-line illustration shots and whenever a DSLR is too conspicuous or just in the way. My DSLR is still the workhorse because of its versatility and image quality. But I always have at least one of them with me and I will use whatever camera is handy to make the best shot possible.