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Tech Prep Consortium Fall 2003 Professional Development
Becoming
a Digital Camera Pro Lynnette D. Morrison http://www.etwebtools.org Digital cameras allow users to take
photographs and store the photographs digitally, instead of on traditional
film. Many digital cameras allow users to review and edit images while
they are still in the camera. All digital images can be downloaded to
computers for editing in various photo-editing software programs. Advantages of using a digital camera:
·
Digital images taken
by a digital camera are instantly available and usable. As soon as you
take a digital photograph, you can use it.
·
You can tell as soon
as you take a picture whether or not you got the shot you wanted. If not,
you can take more shots until you get the ones you want.
·
Digital images are
immediately ready to be used on the Internet.
·
You can delete bad
shots and keep only the good ones before they are printed, so there is
no cost for bad photographs.
·
Digital images can
easily be sized however you want.
·
Digital images can
be used in many ways including for printed photographs, web sites, printed
publications, and e-mail attachments.
·
Digital images can
be easily stored on hard drives, CD-ROMs, and Zip disks. Ways to use a digital camera:
·
Use digital images
in slide shows, screen savers, and photo albums.
·
Print digital images
on specialty papers such as photo-quality paper, labels, business cards,
fabric transfer papers, greeting cards, fine-art papers, etc.
·
Use digital images
in documents created by various types of software programs such as desktop-publishing
programs, word processing programs, spreadsheet programs, and database
programs.
·
Post digital images
on the internet.
·
Send digital images
via the Internet to professional printers for professional print jobs.
·
The quality of digital
photographs depends on many variables. Digital picture quality depends on:
·
The camera user's photography
skills.
·
The optical quality
of camera lenses.
·
Pixel resolution (1-megapixel,
2-megapixel, 3-megapixel, etc.).
·
Camera features used
to adjust picture quality, such as zooming, balance, and special effects.
·
Type of file format
(JPEG, TIFF, proprietary format, etc.).
·
Level and quality of
image file compression used.
·
Image editing software
used.
·
Print size.
·
Printer type and quality.
·
Paper quality. When digital photographs are taken,
digital cameras produce a digital file that is stored on a small magnetic
storage media, similar to what is used by computers. Digital cameras require
storage space on a hard drive, CD-ROM, zip disk, or floppy diskette after
photographs are downloaded from a camera. When the shutter of a digital camera
is pressed, light passes through the lens of the camera and the image
is focused on a chip called a charge-coupled device (CCD). The CCD generates
an analog signal composed of the image. The analog signal (DSP) is converted
to a digital signal by an analog-to-digital converter (ADC). A signal
processor (DSP) adjusts the quality of the image and stores the digital
image on storage media (floppy disk, compact flash card, PC Card, memory
stick, microdrive, SuperDisk, etc.) in the camera. The images are then
ready to be transferred to a computer. A digital camera can be plugged into
a computer for image transfer or removable media, such as a disk, can
be removed from the camera and attached to a computer for image transfer.
Most digital cameras have a television-like liquid crystal display (LCD)
that users utilize to compose their shots. Since digital cameras do not
use film, images can be viewed immediately after they are taken on the
LCD. Users can immediately delete shots they do not want to keep. This compares with traditional cameras
that use film coated with light sensitive chemicals to capture and store
an image. When light hits the coated film, a chemical reaction occurs
and the image is stored on the film. This film has to be chemically processed
for development. Physical prints of the prints are made and may be stored
in the form of negatives. Limitations of Digital Cameras
·
Quality digital cameras
generally cost a lot more than comparable traditional cameras.
·
Generally, image quality
may not be as good as that of traditional cameras and the size of photograph
enlargements may be limited by the digital camera's resolution.
·
Good quality prints
of digital photographs require cameras that shoot at higher resolutions.
These higher-resolution digital cameras are expensive.
·
Digital cameras eat
batteries, so they constantly need to be replaced or recharged.
·
Digital cameras capture
images in two ways, either using static array or linear array. Using static
array, the CCD captures the image in one fast exposure, while using linear
array, the CCD captures the image using a longer scanning exposure. This
means linear array cameras are only suitable for still life shots.
·
It can be difficult
to see a liquid crystal display (LCD) in bright sunlight. Digital camera features, size, shape,
and cost vary greatly between manufacturers and models of digital cameras.
There are now over 250 models on the market. Some have very few features
and others have more than 100 features. Many of these features allow you
to do things that are not possible with traditional cameras such as adjust
white balance for varying lighting conditions, increase brightness, and
create special effects like sepia (golden brown) tones. There are five basic types of digital
cameras:
·
Beginner digital cameras - Beginner cameras are simple, point-and-shoot devices with
few special features. They have a fixed lens (with no special capabilities,
such as focus and zoom), a simple optical viewfinder (no LCD viewfinder),
and built in memory (no removable memory cards. Resolution is from 640-by-480
(VGA) to 1,024-by-768 (XGA). These cameras are designed for people on
tight budgets, those who want point-and-shoot capabilities, and want only
snapshot-size prints. Prices generally range from $79 to $200.
·
Consumer digital cameras - Consumer-level digital cameras have more features than
beginner cameras, but are still fairly simple to shoot. They usually have
an auto-focus lens and some have a zoom lens. Consumer-level cameras have
LCD viewfinders and removable memory cards. Additional features may include
different flash modes, white balance, video out, and various modes for
photographing for special effects such as shooting black-and-white or
sepia (golden brown toned) photographs. These cameras are for those who
want better image quality than beginner cameras and who want to print
larger prints. Most have 1 to 2.2-megapixel resolution. Prices generally
range from $200 to $500.
·
Advanced consumer digital cameras - Advanced consumer-level cameras have a long list
of features, great picture quality, or a combination of both. Most have
excellent auto-focus zoom lenses, many program modes for special effects,
image enhancements (such as flash adjustment and color, contrast, and
brightness controls), and special features (such as wireless remote control,
time lapse, and manual focus). These cameras are for those who want photo-quality
enlargements, many image controls, and a wide range of features and functions.
Most of these cameras have 3.3-megapixel resolution. Prices generally
range from $500 to $900.
·
Prosumer digital cameras - Prosumer cameras are designed for serious photographers
only. They concentrate on precise control, fast operations, and superior
image quality. Prosumer lenses are not interchangeable like professional
models and the image sensors are less sophisticated. These cameras are
for those who want near-film-like performance and image quality, top-quality
zoom, and extensive manual controls. These cameras have between 3 and
5-megapixel resolution. Prices generally range from $1,100 to $2,000.
·
Professional digital cameras - Professional cameras have sophisticated image sensors
that can produce photographs that are indistinguishable (or even better)
than film. They have a wide range of controls that allow the user to have
control over every aspect of the photograph. Professional cameras are
for those who want to use multiple lens, true film-like performance and
image quality, total manual control, and price is not an issue. These
cameras have between 3 to 6-megapixel resolution. Prices generally range
from $4,000 to $15,000. The quality of digital cameras is
typically judged by their resolution. Digital camera resolutions are commonly
expressed as the number of pixels per inch it can capture. A pixel (picture
element) is the smallest point of a bitmapped screen that can independently
be assigned color and intensity. Digital pictures are made up of many
pixels of varying color and intensity, similar to the way a mosaic is
made up of many different colored tiles. The pixel resolution of a digital
camera determines the pixel resolution of the photographs it takes. The
total pixel resolution of a photograph determines the maximum size of
a quality print that can be made using that file. Once the photograph
is taken and the pixels have been captured, the pixel-per-inch value can
be changed. The greater the resolution (or pixels per inch), the larger
the file will be. Digital Camera Resolution and Maximum
Print Size: Resolution per inch -- Maximum desktop
print size (inches) VGA (640-x-480) -- 3.5 x 5-inches
1-megapixel -- 5 x 7-inches 2-megapixel -- 8 x 10-inches 3-megapixel -- 11 x 14-inches 4-megapixel -- 14 x 17-inches 5-megapixel -- 16 x 20-inches Some available digital camera features:
·
Point-and-shoot (fixed focus) or auto-focus - Some digital cameras come with
a point-and shoot feature that attempts to focus everything in the image
for the user. Other digital cameras have an auto-focus feature that gives
the user some control over the focus. Auto-focus cameras generally produce
a better-quality image.
·
Lens focal length and speed - Focal length controls the magnification and the angle
of the view that can be taken with a lens. Lenses can be wide-angle, normal,
telephoto, and zoom. Lens speed determines how much light is required
to take a photograph. Fast lens speeds are better for taking photographs
in low light areas.
·
Optical versus digital zoom capabilities - Optical zoom allows a user to
zoom in on an object by using the lenses. Digital zoom allows zooming
through the use of software. Optical zoom creates much better images than
digital zoom.
·
Macro capabilities - Allow the user to take close-up images.
·
Viewfinder and/or LCD - A viewfinder is an optical window that allows the user
to point the camera, but it does not accurately represent the image that
is being taken. A liquid crystal display (LCD) is a television-like screen
that shows what the picture will look like. Some cameras have viewfinders,
others have LCDs, and still others have both.
·
Image storage media (CompactFlash, SmartMedia, floppy disk, or other) - Various types of cameras use various
types of storage media for the storage of digital images. CompactFlash
and SmartMedia are the most common and have the most storage capacity.
They come in various sizes ranging from 4 MB to over 300 MB.
·
Type of interface between the personal computer and digital camera (generally,
serial or USB) - The interface is what enables the user to connect a digital camera
directly to a personal computer in order to transfer digital images. The
serial cable interface, where a cable connected to a camera plugs into
the serial port of a computer, is by far the slowest. The Universal Bus
(USB) interface, where a USB cable connected to a camera plugs into the
USB port of a computer, is much faster. (Note: Not all computers and operating
systems support USB interfaces.)
·
Image file format, file compression options, and capacity - Digital camera makers offer a
variety of file format options and compression technologies, which affect
a digital camera's capacity to store images. Different formats have an
impact on the quality and capacity of files to be used by various photo-editing
software.
·
Flash capabilities - Digital cameras come with a variety of flash capabilities.
·
Capability to add lenses - Some digital cameras allow for the use of telephoto and/or
wide-angle lenses and others do not.
·
Capability to output to a television - Some digital cameras allow users to connect their
camera directly to a television screen by using a cable that plugs into
the VIDEO IN port on the television or VCR. Often cameras that have this
feature also have slide show capabilities. Digital Camera Tips and Techniques Learning How to Use a Digital Camera
Several digital camera manufacturers
now offer free online courses to teach users how to use specific digital
cameras, including Kodak (http://www.kodak.com). Kodak has an online Digital Learning
Center at their web site (http://www.kodak.com)
that has wonderful free online photography courses including one called
Kodak's Guide to Better Pictures (http://www.kodak.com/global/en/consumer/pictureTaking/index.shtml).
Tips for Taking Better Photographs:
·
Carefully position
the camera and the view for the photograph
·
Shoot with the best
possible light
·
Hold the camera steady
·
Use the flash in shaded
areas
·
Use a simple background
·
Balance the shot
·
Place the primary object
off-center
·
Add a frame for interest
·
Try shooting from different
perspectives
·
Use color for capturing
attention Photo Quality Printers Digital camera users generally want
the capability to print their digital images in their home or office.
Many types of photo-quality printers are available to allow them to do
this. Some produce excellent quality prints and others produce prints
that are not so good. Prices range from $100 to more than $1,500. Current
reviews of photo-quality printers can be found at the PC Magazine web
site (http://www.pcmag.com)
and at the PC World magazine web site (http://www.pcworld.com).
Important photo-quality printer features
for printing digital images:
·
Print quality - Print quality is the most important feature for a photo-quality printer.
A good photo-quality printer will produce even, continuous gradations,
and will not show any banding (straight lines across the printer head
path). Colors should be correct and not faded. Overall, the appearance
of prints of photographs should be close to the way the photographs appear
on a computer screen.
·
Print resolution - Print resolution is specified in dots-per-inch (dpi). Printers with
higher dpi generally print better images than printers with lower dpi.
Dpi affects the sharpness of the image, the smoothness of the gradations,
the details of highlights, and the darkness of shadows. Inkjet printers
with 300 dpi or more are capable of printing a good photo-quality print.
·
Maximum print size - Most standard photo-quality printers can print photographs up to 8
x 10 inches in size. Photographs 8 x 10 inches and larger require huge
image files. An uncompressed 8 x 10-inch color image formatted at 300
dpi can create a file size of 21.6 MB and an 11 x 14-inch image can create
a file size of 41.6 MB. Keep in mind the limitations of the processing
power and storage space of a system.
·
Adjustable printer head height - Some printers, including many of the more expensive Epson
printers, allow for the printer head to be raised to accommodate thicker
fine-art papers, such as watercolor paper or artist canvas.
·
Paper-feed path - Printers that enable thick paper to feed straight into a printer (rather
than a fed that makes paper turn around a narrow-diameter roller) allow
for the use of thicker papers and will give better results.
·
Print speed
- Print speed can be important when printing more than a few prints. Generally,
photo-quality printers are fairly slow, because they are optimized for
quality, not speed.
·
Ink cartridges and print heads - Inkjet printers can be expensive to use. Print cartridges
can run from $15 to $40, depending on the brand and model. Full-page prints
use a lot of ink. Be aware of how ink cartridges for particular printers
are sold. Some printers require a black cartridge and a separate color
cartridge. (Users replace the black cartridge when the black ink runs
out and the color when the color cartridge runs out.) Others require a
single cartridge (black and other colors all in one-if one color runs
out the entire cartridge must be replaced). Still others require cartridges
for four different colors. The type of printer usage can greatly impact
the number of cartridges used. For example, if printing a lot of black
and white photographs, printing on the printer with the separate black
cartridge would be less costly. Paper for Printing Digital Images
The paper you choose for printing
digital images has a major impact on the overall quality of your print.
Types of paper for printing digital images:
·
Standard ink-jet paper - Use standard printer paper for draft or test work, then
print on higher quality paper. Standard ink-jet papers do not have the
weight (thickness) or sufficient surface quality for printing digital
images.
·
High-quality non-glossy papers - High-quality non-glossy papers allow for better printing
quality than standard ink-jet paper. They are thicker than standard paper
and have a non-glossy surface. Use this type of paper for printed publications.
·
Photographic papers - Several good-quality photo-grade papers are available
for use with ink-jet printers, including many sold by Kodak and Hewlett
Packard. Many weights (thicknesses) are available. The paper weight, designated
in pounds, is shown on the boxes of paper. The greater the weight, the
thicker the paper.
·
Fine art papers - Fine art papers, such as watercolor papers, canvas papers, textured
papers, and other papers that create special effects during printing are
available for ink-jet printers. The special effects papers can be used
in conjunction with special effects created in photo-editing software.
·
Specialty papers - Specialty papers are available for the printing of greeting cards,
business cards, labels, stickers, transparencies, fabric transfers, CD
labels, jigsaw puzzles, etc. Top 5 Reasons to go
Digital 1 - See and improve pictures in a heartbeat
3 - Perfect your pictures with "digital
magic"
4 - Unleash your creativity
Digital Camera Terms
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