Digital Cameras

Buying Guide:
Digital Cameras

Buying Guide: Digital Cameras
There is a huge variety of digital cameras available in the market today and it can be a
daunting task to work out which one best suits your needs.
There are a number of things that need to be considered before buying a digital camera and
this guide is here to help you make sense of the different camera types, specifications and all
the jargon.
To make it easier for you to work out which digital camera you need, this guide is split into
various topics. These are:
What types of digital cameras are available?
How do digital cameras work?
What features do you need to consider?
Accessories
Jargon Buster.

What types of digital cameras are available?
There are a wide variety of digital cameras that are available they are grouped into the
following three types to make it easier to find the one you want.
Compact
Compact cameras are pocket sized, lightweight and portable cameras that are full of easy to
use features, such as face recognition and shooting modes. Most feature a small zoom lens
and are capable of taking high quality shots that can be printed out in a variety of sizes. Some
are designed specifically for younger children to use so they are more robust, but may lack a
number of useful features.
High Zoom
These cameras offer all of the features of a compact camera but with an extended optical
zoom lens to capture vivid images from a distance. High zoom cameras can be similar in size
to a compact camera or much larger making them less portable.
High Performance
High Performance cameras and Digital SLR's (Single Lens Reflex) are professional style
cameras that offer cutting-edge technology and greater flexibility. Digital SLR's have
interchangeable lenses and manual settings to give complete creative controls.

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Buying Guide: Digital Cameras

How do digital cameras work?

Digital cameras are not that different
from their 35mm counterparts.
Both types of camera feature the
same core elements of lens,
aperture and shutter but it is the
way they capture and store the
image that's different.

As with 35mm cameras, the lens
system ensures the captured
image is in focus while the
aperture and shutter control the
amount of light that is allowed in.
In a 35mm camera as soon as the
shutter is released, light is let in to
the camera through the lens and
aperture to land on light-sensitive
film. This results in a chemical
reaction which records the image on
to the film.

Instead of light-sensitive film a digital camera uses a combination of CCD (Charge-Coupled
Device), image processing engine and storage media to capture the image.

The CCD is coated with Red, Green
and Blue colour filters and converts
each image into a pattern
consisting of millions of tiny
coloured squares known as pixels.
The image processing engine
evaluates the colour and brightness
data for these pixels and uses it to
produce the correct colour,
brightness and contrast for the
image.

The image processing engine also
sharpens the image and reduces
graininess before transferring the
image to the storage media. The
storage media is flash memory that
is either built into the camera or an
external memory card that is put
into the camera (SD Card for
example).

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Buying Guide: Digital Cameras

What features do you need to consider?
There are a wide variety of features that can be found on digital cameras, some need more
consideration than others as they affect the quality of the image that the camera can produce.
The most important features to consider are resolution, zoom, battery and memory.
Resolution
The resolution of a digital camera refers to the sharpness of the pictures you can take on it
and is expressed in megapixels (MP). A megapixel is one million pixels and is found by
multiplying the number of horizontal and vertical lines of pixels that make up the picture taken
by the camera. A high megapixel camera will give you sharper printed pictures and will also
give you more flexibility to crop or enlarge images.

Zoom
Most digital cameras come with a built in zoom allowing you to get closer to your subject and
there are two types of zoom, digital and optical. Digital Zoom works by enlarging part of the
image to give the impression of zooming in, but this reduces the quality of the image. Optical
Zoom uses a traditional multi-focal length lens when you zoom in and out and this allows you
to get closer to your subject without losing image quality.
Battery
The more photos you take, the faster your cameras battery power is used up, and the flash,
zoom lens and LCD screen can also shorten the life of your battery. The majority of cameras
use a rechargeable Lithium-Ion battery, but some low cost small cameras may use AA
batteries.
Memory
Most digital cameras have a tiny internal memory, which is normally not enough to store more
than a couple of images. Memory cards come in a number types and sizes, the size you need
will depend on the number of photos you want to store on the card and the number of
megapixels the camera has.
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Buying Guide: Digital Cameras

Other features to consider

There is a wide range of other features that can be found on digital cameras. These features
help you to get rid of blur, capture the smile on everyone’s face, and even shoot your own
videos with ease. Some of these features are more useful than others so it is worth looking at
all of the features before deciding which camera to purchase.

Image stabilisation

An unsteady handgrip will blur the still image,
especially in dim conditions or if you’ve zoomed
in a lot. Many digital cameras have image
stabilisation, which steadies the picture so the
shake is largely eliminated. This involves the
optical lens or digital sensor moving ever so
slightly to compensate for hand movements.

Face detection

When taking pictures of people this setting will
automatically detect their faces, ensuring the
focus is firmly on them, not on the scenery
behind them.

Continuous shooting I Burst modes

This lets you take multiple rapid-fire shots with one touch of the exposure button. A useful
feature when photographing motion, such as sporting events.

Scene modes

Most digital cameras can be automatically set up
by selecting one of many scene modes to offer you
a range of options, such as shooting in black and
white or sepia, and as panoramic or macro shots.

Manual settings

In addition to the automatic controls, some digital
cameras come with manual settings, allowing you
to set the shutter speed, aperture size and ISO
speed exactly as you would do with a traditional
camera. Manual focus is useful for close-ups as it
lets you focus on exactly what you want.

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Buying Guide: Digital Cameras

Digital Camera Accessories

There is a wide range of accessories available for digital cameras, some of which are more
essential than others.

Camera Cases

Most digital cameras don't come with a carry
case but they are useful for protecting your
digital camera when it is not in use. There is a
wide range of styles and sizes available, some
are designed for specific cameras, while others
are not. Most cases detail the internal
dimensions of the case so you can check your
camera will fit inside. Many camera cases also
have small pockets for extra memory cards.

Memory Cards

There are a number of different types of memory card available but the three most popular
ones are Secure Digital (SD), eXtreme Digital (xD) and Memory Stick (MS) Pro/Duo. Memory
cards also come in a number of different sizes, the type and size you need will depend on
your camera model and the number of pictures you want to be able to store on the card. The
following table gives a rough idea of the number of images a memory card can store at
different capacities, but these figures will vary from camera to camera.

Tripods

Tripods are a useful accessory for your camera if you need a steady camera for your photos
or if your camera has a large zoom lens. Tripods come in a number of sizes, from full size
height adjustable ones to mini table top tripods and flexible ones that can be secured on
branches or posts.

Memory Card Readers

Memory cards readers can be useful as you can transfer the photos off your
memory card whilst the camera is being used with another card. Each card
reader will read a number of types of memory card so you will need to
check that the card reader is compatible with your memory card. Many
laptops and computers come with them already fitted, or you can purchase
a USB card reader that will plug into a USB port on your computer.

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Buying Guide: Digital Cameras

Jargon Buster
One of the worst things about looking at digital camera specifications is understanding all the
jargon and abbreviations. Hopefully the following list will help.
Auto focus A camera system that automatically brings the lens into sharp focus on the
subject.
Exposure The process of allowing more or less light into the camera and exposing the
image sensor to light, which results in a captured image.
Frames per second (FPS) The maximum number of images a camera can shoot
continuously in one second Important for high-speed action shots.
LCD screen Liquid Crystal Display screen that allows you to frame and review your images
in addition to displaying camera functions and menus.
Lithium ion battery A rechargeable battery that does not require a full discharge before
being charged again.
Megapixel (MP) 1 megapixel (MP) = one million pixels. The more pixels in an image, the
higher its resolution.
Micro SD A smaller version on the Secure Digital (SD) card (see below). A memory card
format that is used in a number of small compact cameras
Red-eye reduction Reduces the unpleasant red eye effect in flash portraits.
Secure Digital (SD) The standard memory card format used in the majority of cameras.
Shutter speed How long the cameras shutter remains open as a photo is taken. High shutter
speeds will freeze moving objects. Lower shutter speeds can add creative blur effects.
Single lens reflex (SLR) A camera with interchangeable lenses, giving the best possible
image quality.
Wide Angle Lens A camera lens with a short focal length, such as 24mm or 28mm

Contact Schools ICT for further information

For more information and prices for the full range of cameras we supply visit
www.schoolsict.co.uk/shop or contact the Schools ICT Development Team on
 01609 53 6086 and choose Option 2
: [email protected]

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