What is digital photography

Strictly speaking, digital photography is defined as the use of a digital camera to capture images. However, this site encompasses the broader meaning, referred to as digital imaging, which includes any means of transferring pictures from the analog to digital world. It includes the use of regular film and slide cameras, with subsequent digitization, most commonly through scanning. It also includes the use of digital cameras, which allow pictures to be taken digitally directly, via media such as compact and smart flash, or digital film backs to conventional SLR cameras.

What are the advantages of digital photography?

Everyone has different reasons for choosing digital photography. I will mention here a few of the reasons I made the transition to digital cameras completely several years ago. After losing several rolls of slide film back to back- to different processors, I became wary of losing precious images. I had lost a roll en route to or from the processor on nearly every trip I've taken over the past 25 years, since shooting seriously, and digital provided a way for me to take control of the processing. When finished shooting, I immediately transfer the cartridge to my computer, and on a weekly basis back it up to compact disc to archive off-site.

Another big plus is, once you make the initial investment in a digital camera (which averages under $1000 currently for top of the line prosumer models, with prices steadily dropping) the cost of shooting is essentially free. On some days in the field, I shoot the equivalent of ten or more rolls of film, and don't pay a thing for film or developing. Because of this, I shoot more freely than I used to, when calculating the cost each time I pressed the shutter. Now, I experiment more with exposure, metering, and even choice of subjects. Where in the past I might have shot one or two individuals of a plant or animal, now I'll shoot a dozen, to make sure I get just the right one, from just the right angle.

Still another advantage is the instant feedback in the field. Using the LCD screen, you can compose the shot visually in the field, and with playback mode can review the shot instantly for sharpness, exposure, and even on some of the newer models (like the Nikon 990 I'm currently using) get a histogram display of the image. Combining this with review after every field session on the computer, and it provides enough feedback right away to determine if the shot needs to be redone. With film, many times by the time I got the developed film back, it was too late to try shooting my subjects again.

Basics of Digital Cameras

What is a digital camera? Traditional film cameras have been in use for over a century - they use chemicals to store images, first on glass, then later on paper and plastic. The chemicals are light-sensitive - they change chemically in very predictable ways when exposed to light. That is the essence of any camera - the ability to record differences in light very precisely. A digital camera, instead of using direct chemical reactions to store variations in color, uses an integrated circuit that is light sensitive. As different wavelengths and intensities of light strike the light sensitive integrated circuit in the camera they create very small electrical charges. These electrical charges are recorded as binary (zero and one) values in a digital format and stored. A digital camera is actually a small specialized computer with a light sensitive chip to record images. Most modern digital cameras store the pictures taken in the same format used to store pictures on the Internet. The pictures are stored as computer files on CompactFlash(CF) cards, or other small memory devices. IBM even makes a small hard disk that is used in some of the more expensive digital cameras.

Why use a light sensitive computer to record images instead of a traditional film camera? There are several reasons:

1) Digital "film" can be re-used - with traditional film cameras, film can be used only once. With a digital camera, the CF card or other electronic component used to store the images can be erased and used over and over again. You can usually erase pictures while the camera is in use, giving you the alternative to shoot an unlimited number of pictures if required.

2) Most publishing is computerized. In addition to the Internet, which is only computers, newspapers and magazines have for decades been computerized. Images and text are stored on computers during the composing stage. Traditional film pictures have to be converted to digital form via a scanner before they can be printed. Using a digital camera saves this scanning step - the second the picture is taken it is stored in the same format it will be published in.

3) No developing is necessary. It usually takes a few seconds to complete the digital conversion and storage steps on a digital camera. No chemical developing step is necessary to take the original film and convert it to prints or slides as is done with traditional film cameras. This means you can get instant input on how your pictures look. You can hook the camera up to a computer or a TV and look at your pictures within minutes after taking them.

4) Digital cameras have fewer moving parts than film cameras, and generally are less prone to outright mechanical failure. Exposing the "film" to light in a digital camera causes no harm, and since pictures do not have to be sent to a lab to be developed, there is no chance of pictures being lost at or in transit to a remote lab.

If digital cameras are so nifty, then why do film cameras still exist? There are several disadvantages to the current generation of digital cameras:

1) Digital cameras are more expensive to purchase than conventional film cameras. Digital cameras, however, are less expensive to operate, since you do not have to buy film or pay for developing.

2) You need a computer to get real use of a digital camera. Many inexpensive inkjet printers now print out very nice photographic quality prints.

3) Picture quality in digital cameras is not as good as high end 35 mm cameras. The gap is narrowing, but 35mm slide and print film still get better quality if you actually look at the prints or slides. If you are planning to use the pictures electronically (on web sites, etc.) then this difference disappears, since it takes a very expensive scanner to get a digital image as good as one produced by a good quality digital camera.

Each month brings new digital cameras, and cheaper prices on older digital cameras. While a computer will remain a critical accessory for a digital photographer for years to come, picture quality is improving rapidly, and price is dropping every bit as fast.