Let me declare my hand first. Curiously, I feel something of an outsider
peering in at the ‘great debate’ which pitches digital photography
against traditional analogue photography. I am really more interested in pictures
than cameras. I think the right camera is the one that produces the sort of
pictures you want to see.
The beauty of digital imaging is that it delivers almost instantaneous feedback
and results. Film-based photography simply cannot compete on this. Further,
the digital imaging process – from image capture to print, file
upload or publication – is also not only quick, but gives the photographer
an extraordinary amount of control over how the image is presented. This freedom
of control (to control levels, curves, contrast, achieve perfect colour balance,
'clean up' and manipulate images, and so on) can be very satisfying, but easily
gobbles up huge amounts of time. Note, too, that digital cameras are essentially
disposable: their resale value drops quickly and dramatically, and any repairs
required outside of warranty are likely to equal the camera's original price.
Tip 1 Ignore styling
– you’ll pay a premium for the latest styling, which will go out
of fashion the following day.
All cameras, whether digital or film-based, are based on optics (so any experience
with analogue cameras provides a good basis for underestanding digital cameras).
Where the two media differ is in how they process and retain the image. Very
simply put, the ‘film’ of the digital camera is a CCD sensor in
which picture information is produced by photo-diodes which change light into
an electric charge for each pixel. CCD is short for Charge Coupled Device.
Tip 2 If you want good
quality images, buy a camera with a good quality lens.
Reading professional camera reviews in photo and digital camera magazines
will give a good idea where camera and lens quality lies.
In my research I found that understanding some of the processing features
available in digital cameras greatly helps you decide which camera will best
suit your needs. Some of the more basic features are sketched out below. Before
delving into these directly, though, ask yourself – and keep in mind
when shopping – a key question:
Key question: How much control do I need
over the final result to get the type of pictures I want?
Knowing what kind of pictures you want to produce goes a long way towards
helping you ignore irrelevant features and to focus on necessary and useful
ones. Again, search out reviews. On-line reviews can be especially good for
discussions of camera features, with comments and insights posted not only
by professional reviewers but also photographers, keen amateurs and those
who already own and use the equipment. For example, a useful overview of digital
cameras available along with reviewer opinions can be found at Future
Publishing (www.futurenet.dealtime.co.uk).
Manual Control Almost all digital cameras have some type
of automatic or programme mode that allows you to point, shoot and produce
a picture. If this is all you need, then really you only need to focus on
issues of camera and lens quality.
Some cameras also have (or only have) useful pre-set modes for various typical
photo situations, such as photographing landscapes, portraiture, fast moving
sports, night scenes and so on. If, like me, you like lots of control over
your camera, look for these modes: aperture priority; shutter priority; full
manual (where you set both). Some digital cameras will allow you to construct
and pre-set your own modes – to fit your personal picture-making habits,
style and subject matter.
Metering Digital capture lends itself nicely to sensing
different points, areas or patterns of an image captured on its sensors, and
there are dozens of metering modes available. Standard modes include: spot
metering; multi-spot metering (you select which points of a picture, and how
many, are metered), and centre-weighted.
White Balance White balance allows you to adjust camera
exposure for different types of lighting conditions, such as daylight, overcast,
tungsten lighting and different types of fluorescent lighting. Not unlike
selecting different film stock.
Flash Most cameras have built-in flash and a number of
flash modes, including auto, forced flash, flash off and red-eye reduction.
A proper fill-flash function could also be very useful. Check out the degree
to which you can control flash output if this is important, and whether there’s
a hot shoe to attach a flash head, or a flash sync socket for off-camera illumination
if you’ll need it.
Zoom Clearly one of the most useful features of a non-SLR
type of digital camera – to gain more control over composition and character
of a picture. Optical zoom is the only true guide to a len’s range of
coverage. ‘Digital zoom’ simply enlarges a section of the camera’s
CCD sensor, giving you an enlarged image but at reduced resolution.
Miscellaneous Controls Many cameras allow you to fine-tune
aspects of an image, including contrast, sharpening and colour saturation
(things PhotoShop does better, if you’re so inclined). Some models have
auto-bracketing features, which allow you to set a variety of over/under exposure
parameters as well as select the number of bracketed exposures taken in a
sequence.
Most standard and prosumer digital cameras use a large amount of compression
simply to capture a reasonable number of images, and all compression algorithms
essentially throw away picture information. The trick is to throw away only
image information that the human eye doesn’t notice. The compression
systems of some camera manufacturers do this extremely well and produce very
fine image detail. Other systems throw out too much information. Indicators
of aggressive compression are isolated pixels of colour in areas of contrast
and along diagonal edges within a picture, and artifacts (rogue collections
of pixels) appearing in areas of otherwise flat colour.
The variety and complexity of the different compression systems makes it almost
impossible to objectively correlate a camera’s pixel count with its ability
to resolve detail. Ultimately, the proof is in the pudding, and a comparison
must be made between like images produced by different cameras. To some extent
this can be done in shops that are happy to open images up on a monitor for
you, or print them out – usually when business is very quiet. An alternative
is to visit the Imaging Resource site (www.imaging-resource.com) and use their
‘Comparometer’
– a pair of windows in which you select two different cameras and a variety
of pictures taken by each are downloaded and displayed side-by-side. The comparometer
is presently being updated and expanded, but a basic manual method is still
available.
Go into shops and handle a range of digital cameras to see how they feel in your hands and operate. Ask questions. Look for a quality lens. Draw on the reviews you have read to work out which digital features are important to you. Then choose the camera that will help you to produce the type of photographs you want to see and share with others.
Jim Batty
jimbatty.com image library
Text and photographs copyright © 2005 by Jim Batty. All rights reserved.
No part of this work may be reproduced, stored in a retrieval system, or transmitted,
in whole or in part, in any form or by any means, without signed written permission
from the author.
This article was originally inspired by a colleague putting together a design handbook and is based on research I did for an organisation which wanted a digital camera that could produce decent portrait photographs for the web and 1/4-page-sized promotional images for commercially (litho) printed brochures – within a budget of £300.
A number of people have found it useful when buying their first digital camera, and versions of the article have appeared in the Sutton Camera Club's In Camera News and the Richmond and Twickenham Photographic Society's Format.