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This page moved to its new location on the Tripod home page server 8 July 2000.
This is the second draft of my Basic Photography Guide which I have been writing bit-by-bit for over five years! It is intended as a possibly incomplete guide for beginners and those with some experience. In particular, the sections on flash and macro photography will appeal to those who have progressed past the basic concepts of aperture and shutter speed.
All of the photographs on this page were taken using Canon or Praktica equipment. A larger version of each image is available by clicking within the frame.
Although I am not a professional photographer, I have done quite a lot of photographic jobs for various people (weddings, portraits, portfoilio shots etc.) when time permits. If you live locally (in the South West of England, within 20 miles of Swindon) and need some photographs taken (any subject considered) at a reasonable cost, then it might be worth contacting me by email.
Please e-mail me with anything you would like to see here, any errors or omissions and comments. I am always pleased to hear from people who have found my guide useful (or not!), but please don't ask general questions about photography - I just don't have the time to answer them.
Enjoy your photography!
Shutter speed is a measure of how long the shutter remains open when the picture is taken. On manual cameras, it is usually set by means of a dial on the top of the camera or, less commonly, a ring around the base of the lens. Automatic cameras usually denote shutter priority mode with the symbol Tv which simply means "Time value". Typical shutter speeds are 1/1000s, 1/250s, 1/15s and 1s. Note that shutter speeds are calibrated to be approximately twice as fast as the previous setting and twice as slow as the next setting. For example, 1/250s is twice as fast as the previous setting 1/125s but is twice as slow as the next setting 1/500s.
There is often an extra shutter speed for
bulb exposures in which the shutter remains open for as long as the
shutter release button is held down. This is handy for exposures of
several minutes, such as this night-time shot on the left.
Most modern SLR cameras have shutters known as focal-plane shutters. Associated with this type of shutter is a flash-sync speed which is the fastest permitted shutter speed when using flash.
Shutter speed plays an important role in avoiding camera shake which happens when the camera moves relative to the subject whilst the shutter is open, causing an overall blur. To avoid this, a good rule of thumb is select a shutter speed which is near to, or faster than, one divided by the focal length of the lens. For example, with a 50mm lens the slowest hand-held shutter speed would be 1/60s and with a 300mm lens it would be 1/500s.
These pictures are an attempt to show the effect of choosing different shutter
speeds and what sort of shutter speed is sensible in certain situations.
The picture on the right was taken in
Bradford-on-Avon
at the starting line of the annual pancake race.
The idea was to blur the competitors, keeping the background sharp,
and so conveying a sense of motion. The shutter speed chosen was
deliberately slow at 1/60s. This was enough to avoid camera shake with
a 24mm lens, but blurred the runners sufficiently as they sprang into motion!
The effect is easier to see if you click on the picture to bring up the
full-sized version.
The technical definition of aperture value, or f-stop
as it is often known,
is the ratio of the focal length
of the lens to the diameter of the
lens opening. In other words, it is the number of times the diameter
of the hole through which the light has to pass will fit into the focal
length of the lens. The size of this hole, known as the aperture,
may be controlled by turning a collar usually located at the base of the
lens. On automatic cameras, aperture priority mode is often
denoted by Av which means "Aperture value".
Typical values may be f2, f2.8, f5.6 and f16 where the "f" denotes
the f-stop, often referred to as f-numbers.
Fortunately, for most of the time we don't have to think of the aperture
value in terms of its technical definition or precise meaning!
All we need to know is that smaller f-numbers (f2, f2.8 etc.)
represent wider apertures (i.e. more light can pass through the lens in a given
time) and higher f-numbers (f11, f16, f22 etc.) give narrower apertures
(meaning that less light passes through in a given time).
The clever bit about this confusing arrangement is that the f-stops are
calibrated to allow exactly half as much light through as the previous
setting and twice as much light through as the next setting (in a given
time of course). For example, a lens set at f8 will allow twice as much
light through as one set at f11 but only half as much as one set as f5.6.
It's no coincidence that
shutter speeds
are also calibrated to be twice
as fast or slow as the next or previous setting which allows us to see how
changing the aperture affects the shutter speed required and vice versa.
The amount of depth of field is controlled solely by magnification
and aperture. Since the magnification is normally fixed for a
given suject, the depth of field is usually controlled by aperture alone.
Wide apertures (such as f2, f2.8) give less depth of field whilst
narrow apertures (such as f16, f22) give much more depth of field.
This control is very important when deciding how to isolate a subject
or where to direct the viewer's attention.
Look at the picture top right which is a townscape view
of
Bradford-on-Avon with a garden rockery
in the foreground. The foreground was only a few feet from the camera
and the background view stretches to infinity (virtually!).
To maintain such a great depth of field on the 50mm lens used,
it was necessary to select the narrowest available aperture of f22.
Careful focussing using the depth of field scale, which is
usually marked on the focussing scale of the lens, showed that
sufficient depth of field was available at the minimum aperture.
This technique of isolating the subject using depth of field is very
effective, particularly for portraits such as
this and
this, in which the viewer's
attention should be directed to the subject and the background left
out of focus to avoid clutter. Note how the background can still
be important, although out of focus, to indicate location or the
mood of the shot.
For a fully technical definition of depth of field involving some
nice equations and diagrams, including the definition of the well known
circle of confusion, click
here.
This picture on the left was taken with a wide-angle lens,
and shows the distorting effect they can have on ordinary subjects.
Having chosen between colour and monochrome, you now have to choose what
medium you want your final image to be on. The choice is split between
prints (from negative or print film) or
slides (from transparency or slide film).
Consider the practicalities of each: passing round a box of slides at a
party isn't as easy as showing prints, but slides can look stunning when
projected on a white screen. Although it is possible to obtain prints
from slides and vice versa, the best advice must be if you want prints
then choose print film and if you want slides then choose slide film!
Slides are predominantly colour although some specialist monochrome slide
films are now available.
Film speed is a measure of how sensitive the film is to light and is
measured by an ISO number (previously known as ASA and DIN).
High sensitivity films are often called fast and low sensitivity films
are called slow.
Standard film speeds are ISO 100, ISO 200 and ISO 400. A film rated at
ISO 200 needs half as much light to form the same image density as
one rated at ISO 100. Note that ISO 400 is one stop faster than ISO 200
and two stops faster than ISO 100.
Fast films can also be used in daylight to obtain the fast shutter speeds
required to freeze action sports.
Slow films are best used for subjects which keep still such as landscape,
architecture and still-life. The use of a tripod and a cable release is
advised to avoid the dreaded camera shake associated with slow shutter speeds.
The trade-off between using fast and slow films is that the grain
(the crystals from which the image is made up) of fast films is much
more visible than that of slow film. Therefore, slow films generally show
more crisp detail than fast films, and colours can be much more
vibrant and saturated. Having said that, modern fast films (in particular
those around ISO 400) can give amazingly good results for very little loss
in image quality!
However, first it is necessary to
understand the following simple technical details about flash:
Very often you will be faced with a subject in which the contrast between
highlight and shadow is too great for the film to handle.
Pictures of people standing in direct sunlight or with their backs to the
sun are just two examples. In the first case, harsh shadows will be cast
across the subjects' faces, making eyes look sunken and noses very
prominent. In the second case, the exposure for the
subject will leave the background overexposed and washed out.
In this photograph, right, a blip of fill flash from an automatic flashgun
was used to separate the
bird (in shadow) from the brightly lit background.
The light output from a typical flashgun
lasts between 1/1000s and 1/10,000s (depending on power)
which is enough to freeze
most subjects, moving or not!
Unfortunately, most fast moving subjects will be out of range of a
flash exposure, but when it is possible to get close enough a good
technique is slow-sync flash. The idea is to select a slow shutter
speed (metered for the ambient light) and at the same time "freeze" the
subject with the correct flash exposure. Results can be unpredicatable,
but depending on shutter speed, you will see the moving subject frozen
in time with a streaky "ghost" image in front or behind. This is a very
good technique to indicate movement in sports such as cycling or rallying.
If you try this then find out about rear-curtain sync (if your
flashgun/camera has it).
Slow-sync flash can also be useful during long exposures (such as an
floodlit building at night) to provide illumination to the foreground.
Flash is particularly useful in
close-up and macro photography
where small apertures
would normally require long shutter speeds
leading to problems with camera shake. The very short distances involved
(< 1m) mean that even the most pathetic flashes (GN around 10) can
be used with small apertures. Specially for close-up work,
a ring-flash, which is a flash with a tube
shaped like a doughnut, is designed to fit around the front of
the lens and provide shadowless lighting.
Most lenses have a "macro" setting marked on the focusing scale,
but this is not true macro, just extreme close-up.
There are several ways to obtain good close-up pictures.
A close-up dioptre lens, which screws on to the front of the camera lens,
is perhaps the cheapest way of making your standard lens focus closer.
Several of these lenses may be used together to acheive magnifications
up to about life-size. Unfortunately, quality begins to suffer, particularly
around the edges of the image, as magnification increases.
Extension tubes fitted between the camera and the lens will also
decrease the minimum focussing distance. Metering may become a problem
since quite a lot of light is lost due to the extension, and exposure
times of several seconds may be required.
Back to my home page (try my photography quiz!).
This heron flew away as I approched him using a 105mm zoom lens.
Because of low light levels, the best shutter speed available was 1/60s.
By tracking the bird as it moved, keeping it in the center of the frame
and following through as the shutter was released, I was able to keep
the head neck and body reasonably sharp and at the same time blurring the
background and wing tips.
This technique is known as panning and helps to convey
a sense of motion.
I can't pretend that this picture was any more than good luck!
Aperture
Depth of Field
Depth of field can be thought of as the amount of the image which has
acceptable sharpness. This means that either side of the selected point of
focus, there is a region in which the image remains in focus. Moving outside
of this band of focus (towards or away from the lens), the image becomes
progressively more unsharp and out of focus.
The picture on the left uses shallow depth of field to direct the viewer's
attention to the subject (this is not as easy to see on the small picture,
click inside the frame to receive a larger version). Notice how the
immediate foreground and the background are out of focus, but there
is a band of focus (look on the path) in which the subject sits.
Focal Length
One of the most significant properties of a lens is its focal length.
Loosely speaking, the focal length of a lens is the distance that it
should be held from a screen in order to project a focussed image on that
screen. This is not exactly true for camera lenses which are actually
made from complex combinations of single lenses. Fortunately a 500mm lens
does not necessarily have to be 500mm long!
The importance of focal length is the angle of view obtained.
The longer the focal length, the narrower the angle of view and the more
magnified the image is (at a fixed distance).
Short focal length lenses are known as wide-angle with typical focal
lengths of 20mm, 24mm and 35mm. Standard focal length lenses are around
the 50mm mark and the range 80mm-300mm are considered telephoto lenses.
Anything above 300mm is regarded as super-telephoto.
To illustrate this, look at the pictures of the telephone boxes (top left and
below right). The picture on the left was taken with a wide-angle 24mm lens
and the one on the right with a telephoto 300mm lens.
Notice how, in both cases, the telephone boxes fill the frame, but the
perspective in each shot is very different.
Telephoto lenses tend to compress perspective making objects look
closer together, whilst wide-angle lenses distort and can make fairly
close objects (such as the furthest telephone box) seem very distant.
Contrary to popular belief, depth of field
does not depend on the focal length of the lens.
Depth of field is determined only by the magnification of the image,
and although telephoto lenses magnify more than wide-angles (at the same
distance), the depth of field in a picture taken by a 24mm lens will be the
same as that in one taken by a 300mm lens if the subject is the
same size in each. Therefore, the depth of field in the two pictures
of the telephone boxes is the same!
Film
Your choice of film is very important when deciding what type
of pictures you are going to take.
One obvious choice is do you want colour or
monochrome (black and white) pictures?
Black and white is good for pictures of people (left) and other
subjects in which
colour might be a distraction. It is also much easier to process and print
your own black and white shots, making it the ideal choice for the beginner.
It would be impossible to discuss all the reasons for choosing colour
or black and white. Most of the time it comes down to personal choice
or expense and you will have to make up your own mind!
Pick your film speed depending on your application. For this theatre shot
(right), the low light levels meant that a very fast film was required to
allow shake free shutter speeds.
The use of flash was not permitted
and would have destroyed the
atmostphere of the shot, so I used Fujicolor ISO 1600 colour print film
and a tripod to obtain shutter speeds of about 1/60s - 1/125s.
Flash
Many people are reluctant to use flash with an SLR camera,
either because they think it's too difficult or because they've tried it
before but with poor results. Other people think that flash is only
useful indoors when there is not enough light.
None of this need be the case - using flash
can be very easy and also very creative! This picture on the left was
produced using multiple flash exposures, moving the subject between each one.
Many other creative examples are easily achieved with even the most basic
of flashguns.
Most important of all, you should get to know your flashgun intimately.
If it has different settings or a distance calculation scale, play with
them - don't be afraid to experiment; waste some film if necessary!
Some flashguns even have a separate manual - read it!
Together with the basic details above, at the very least you will have fun
and you might end up with some great pictures!
Fill Flash
Fill flash is one way to reduce the contrast in these situations by
balancing the available light source (known as ambient light)
with a controlled flash exposure. For a more natural effect, the flash
exposure should be less than the ambient light exposure. Normally the
ratios are 1:2 (1 stop flash underexposure) or 1:4
(2 stops flash underexposure). Fooling the flashgun into providing the
correct flash level depends on the flashgun you are using.
Some have a power reduction facility, others you will have to "lie" to
i.e. tell it you are using f5.6 when you are really using f8 for a 1:2 ratio.
Other Uses for Flash
Close-up and Macro Photography
Close-ups and macro photography are particular favourites of mine,
and that's why there are so many pictures in this section!!
There are four major categories of this type of photography:
The magnifications refer to the size of the image on the film compared to
its size in reality. Thus 1:1 is life size, 1:2 half life size etc.
Both of the above methods require a standard lens to do something which
it is not really designed for; that is focus very close to the subject.
Lenses which are specifically designed to focus at close distances
are called macro lenses (even though they may not always cover
the true macro range) and should give high quality results if used
properly. All of the images in this section were taken with a 50mm
macro lens. The flower arrangement (top left) could be described as
being in the close-up range. Moving in closer, the flower picture
on the right is an extreme close-up of magnification about 1:2.
As the subject magnification increases,
the depth of field decreases drastically!
At life-size magnification the depth of field at f2 is 0.24mm,
at f4 it is 0.48mm increasing to just 3.8mm at the maximum f-stop
(for my lens) of f32. Such narrow apertures can require very long shutter
speeds which means that steady support is needed to avoid camera shake.
A sturdy tripod is essential
although problems with even the smallest vibrations (such as the reflex
mirror flipping up) may be
encountered at such high magnifications.
Possibly the best solution to this problem of camera shake is to use
flash.
If the flashgun is mounted on the camera in the usual way, the
lens may cast a shadow over the subject due to how close the
lens is focussing. To overcome this, the flash may be
connected to the camera with a flash-sync lead, which is basically a
length of wire but will still cost you 30 quid for a
TTL version!
This picture on the right was taken
at life-size, with an aperture of f32, using a flashgun and off-camera
flash sync-lead. The flash has provided a nice catchlight in the eye
and good depth of field has been maintained.
The End
If you have enjoyed your stay, then please take a minute to
let me know,
or sign the visitor book.
Questions, questions!
Understandably, I receive a lot of questions from people keen to learn more
about the wonderful world of photography. I am more than willing to answer
your questions, BUT, please don't e-mail them directly to me - I don't
have time to answer individual queries. You will receive much better
attention by joining my
PhotoCritique
discussion group and posting your question there. Join either with the
above link, or try
this online form.
Hope to see you!
© Copyright notice: All images and text on this page are
copyright
of R. E. Slade.
