Graphics Programs Reference
In-Depth Information
Does this mean you should shoot film only? Of course not; it's get-
ting awfully difficult to even buy film these days. Ultimately, film
captures a high-quality image that can be optically enlarged using
the negative. However, digital capture can be more convenient
and affordable because you eliminate the time-consuming pro-
cesses and costs associated with developing the film. Huge strides
have made in the improvement of image quality in digital cam-
eras, and the ability to experiment and shoot multiple exposures
with real-time feedback makes them a much better learning tool.
It is important to shoot at a high pixel count (which can be accom-
plished by setting the camera to shoot in a high- or best-quality
mode or choosing to shoot raw). You can always crop or shrink
the image for output or display, but you should avoid enlarging the
image if you don't have to. When a digital image is enlarged, it can
create unwanted image softness or pixelization (a visible blocki-
ness). Capture as much pixel data as possible to minimize digital
upsampling (increasing the resolution of the image).
Shooting JPEG vs. Raw
When digital cameras became commercially
available, the memory cards used to store pic-
tures were very expensive. Many photographers
couldn't afford multiple or high-capacity cards,
so they wanted more images to fit on a single,
smaller card. Many users also emailed their
pictures to friends and family. Small file sizes
enabled consumers who lacked an understand-
ing of digital imaging to attach photos to emails
with minimum technical headaches. With these
two scenarios in mind, manufacturers turned to
an Internet-friendly format, JPEG ( Joint Photo-
graphic Experts Group). It was a proven technol-
ogy and one that was familiar to many users.
The JPEG format is extremely common because most hardware
and software manufacturers have built support for it into their
products. The JPEG format is also extremely efficient at compress-
ing images, and it is a good format for continuous tone images,
such as photos. A JPEG file looks for areas where pixel detail is
repeated, such as the color blue in a photo of the sky. The file then
discards repeated information and tells the computer to repeat
certain color values or data to re-create the image.
