Technological advances
have made digital cameras increasingly attractive alternatives
to traditional film cameras. Digital photography has
some advantages, in particular for travel photography.
When a picture is taken it can immediately be reviewed,
without the need for them first to be developed, allowing
a photographer to practice with settings and retake
pictures when necessary. The images are stored on removable
memory cards and can be printed using home equipment
or high street or online services. Digital photographs
can be downloaded to a computer, distributed by email
and used to create Websites, online galleries or printed
documents.
Picture quality is determined by the number of pixels
it contains. One Megapixel equals a million pixels.
A camera's maximum resolution is important, as it determines
how much images they produce can be enlarged. Standard
35 mm film has a resolution of approximately 9 Megapixels.
Reasonable 8" by 10" photographs can be taken
using 2 Megapixel or higher cameras. Low resolution
images are suitable for use in Websites. Printed material
is usually produced at 300 dpi, which for most people
is the visible number of dots per inch.
A variety of computer graphics packages are available.
Using such pixel-based bitmap editing software, photographs
can be improved or cropped and red eye removed. Their
tools and filters enable special effects to be created
and defects removed. When used with desktop publishing
and vector drawing software, text and illustrations
can be added to images. Products such as posters, cards
and books can be created. Pictures can be saved in a
range of formats. TIF file format is often used, because
it does not loose quality. JPEGs are compressed in order
to reduce storage space, but each time they are saved
or edited the quality is reduced. |
