Photography
Camera Types
Most people are aware of the two major camera types, Compact and
Single Lens Reflex (SLR). Compact cameras are designed for the
consumer market and are very easy to use, with focus and exposure
settings automatically set by the camera. SLR cameras offer the
same point and shoot convenience as compacts, but have the option
of manual control and the versatility of interchangeable lenses.
SLRs are designed more for the serious amateur or professional
photographer. Both camera types are capable of producing very
clear and bright images.
Most compact and SLR cameras use 35mm film, but some are designed
to use the newer Advanced Photo System (APS) film. The two film
formats are not interchangeable. A camera designed for 35mm film
will not accept APS film, and vice versa. When processing the
exposed film, the photo developer can place either type of film
onto disk or CD, enabling a home user to load the photos onto
a computer. Many photo developers offer Internet access to processed
photos, offering the consumer the convenience of downloading electronic
versions of their photos directly to their computer.
A third camera type has entered the marketplace in the form of
Digital Cameras, which don't use film at all. Images are stored
digitally in the camera's internal memory, on removable memory
cards, or floppy disks. Digital cameras can be connected directly
to personal computers, so photographs can be easily transferred
from the camera to the computer for storage, manipulation, or
uploading to the Internet.
When comparing digital cameras to compact and SLR cameras, the
term analog refers to any camera that uses film, and digital refers
to cameras which use digital technology to store photographs.
________________________________________
Compact
Compact 35mm cameras are the most common and easiest to use, offering
point and shoot convenience. An automatic flash is usually built
in. Often, the single, non-interchangeable lens offers a modest
zoom range, from medium wide view to medium close up. This zoom
range greatly enhances the camera's versatility, enabling the
photographer to better compose scenes without having to change
position.
Viewing is done through the camera's viewfinder, which usually
offers a fair approximation of the scene. Because the viewfinder
is slightly offset from the lens, the view is never completely
accurate. Some camera viewfinders are better than others in this
regard.
The film speed rating is automatically detected by the camera,
which is used as a basis for setting the exposure values for the
shot. Focus and aperture settings are done automatically by the
camera for optimum exposure. Most cameras produce very good results,
but there are some circumstances that can fool the camera's automatic
settings.
For instance, most cameras try to focus on the object that is
closest to the center of the frame. If the center of the photographer's
interest is outside that area, the camera may focus on the background
and not the intended subject.
The main advantages of compact cameras are their compact size,
relatively low cost, and the ability to produce very good photographs
under most conditions, with minimal input from the user.
________________________________________
Single Lens Reflex (SLR)
Single lens reflex cameras have that universally recognized "camera"
shape, consisting of the camera body and a detachable lens. The
camera has various attachment points for accessories such as a
tripod, remote shutter release and flash. Most new models contain
a small built in flash, while retaining the "hot shoe"
for a larger detachable flash.
The viewfinder's light path is directed from the lens via a mirror
and prism, so that the photographer can see the image through
the lens itself. This offers the greatest accuracy when focusing
and composing a scene, because the same image is projected onto
the film during exposure.
The term "single lens" refers to the fact that a single
lens is used to both view and photograph your subject, while "reflex"
refers to the mechanical operation of the camera during exposure.
Normally, the light from the lens is immediately reflected upward,
through a prism, and then out the viewfinder for the photographer
to see. When the shutter is released, the mirror momentarily moves
up and out of the light's path in a reflex action, so that the
light can be focused onto the film at the back of the camera.
During exposure, the light passes through the lens directly to
the film, without being reflected by the mirror to the viewfinder.
This is why the image temporarily vanishes from the viewfinder
when the shutter is released.
The main advantage of the SLR is its versatility. The photographer
can choose from automatic, semi-automatic, or completely manual
control over shutter speed, aperture, and focus, and can thus
tailor the shot for specific needs. The lens of the SLR is interchangeable,
offering nearly unlimited choice of optional lenses with differing
focal lengths, from wide angle to telephoto. Some lenses offer
an adjustable zoom range, while others are of fixed focal length.
Some lenses have a macro setting, for extreme close-up photography
of objects just a few inches away. It is possible to attach filters
to the lens, for interesting visual effects.
There are many optional accessories the photographer can purchase
for an SLR camera, to customize the photography experience or
to fill specific requirements. Some accessories include a control
for off-camera flash units (for improved lighting of the subject),
motor film advance that allows the shooting of several frames
per second, and tripods which can provide a stable platform for
longer exposures.
Disadvantages of the SLR include a relatively bulky size when
compared to the smaller compact cameras, and the high cost of
some full-featured models and accessories.
________________________________________
Digital cameras
Introduced in the late 1980's, digital cameras have improved in
quality and price to the point of being worthy competitors to
analog compact cameras.
Digital cameras take photographs by focusing light from the lens
onto a charge-coupled device (CCD), which converts the light to
electrical signals. The data is projected onto a grid of pixels,
with each pixel assigned a color and brightness value. All the
pixels taken together form the entire image. The image data is
then stored in the camera's internal memory, on a memory card
or floppy disk, if present. All digital cameras have a small preview
screen to view the images stored in memory.
The camera can be connected to a personal computer for downloading
the photos to the computer's hard drive for storage. One can then
easily view, print, or post the photos to the Internet, if desired.
The number of pictures that can be taken depends on the memory
capacity of the camera (or card/floppy), and the resolution setting
for the photograph. Most digital cameras have several resolution
settings. Low-resolution photos take up less memory, but may be
too small to print or enlarge to the desired size without losing
detail. These photos are fine if they will only be used for monitor
display. Because of their small size, they are also ideal for
uploading to the Internet.
High-resolution photos take up more storage space, but the extra
information present in these photos produces better results when
printing or enlarging. If they will only be displayed on a monitor
screen, this extra detail is usually unnecessary. Additionally,
the large file size of high-resolution photos can make them impractical
for uploading to the Internet.
Exposure control and focus is automatic, but some digital camera
models offer a degree of control over shutter speed, aperture,
and focus. Lenses are usually not interchangeable, but some models
have a wide zoom range. The regular zoom range (optical zoom)
can be enhanced by the camera's built in software (digital zoom),
for a stronger telephoto effect. Digital zoom can be effective,
but when taken to extreme the image can take on a "pixelated"
appearance. This is because digital zoom enlarges the pixels that
make up the image, not the image itself.
Since there is no film to develop, users can avoid the expense
and delay associated with film processing. The photos are digital
to begin with, so there is no need to have prints or negatives
scanned to load the images onto a PC. Images can be viewed immediately
using the camera's preview screen, viewed on a computer monitor
or printed within moments of the snapshot being taken.
At present, the disadvantages of digital cameras are cost and
image quality, though each is improving rapidly. The average purchase
price is currently higher than analog compact cameras, and the
image definition of most digital cameras is not on par with that
of 35mm film, although some high-resolution cameras come very
close to matching this quality.
Film
35mm
The most popular film type for compact and SLR cameras is 35mm.
This film format is inexpensive, versatile, and can produce excellent
images, even for moderate enlargements. Many professional photographers
use 35mm film exclusively. More camera models exist for 35mm film
than any other type, providing the consumer with the greatest
number of choices. 35mm film rolls are available in 6, 8, 12,
18, 24 and 36 exposure lengths, with 24 exposures being the most
popular.
________________________________________
Advanced Photo System (APS)
The newer Advanced Photo System uses film that is slightly smaller
than 35mm, enclosed in a special cassette for easier loading into
the camera. The film exists in 15, 25, and 40 exposure lengths,
and is used in compact and SLR cameras that have the APS designation.
Unlike 35mm, APS incorporates several convenience features. For
example, you can choose from three print formats when taking the
picture, normal, wide, or panoramic. The film includes a magnetic
strip that stores information on exposure, such as print format,
number of exposures left on the film, and other information. The
mid-roll change feature on some cameras uses this information
to let you change film rolls without losing exposures. The camera
automatically winds and unwinds the film into the cassette, for
safe removal and reloading into the camera.
At processing, an index print is provided, containing small, numbered,
'thumbnail' representations of the entire roll of photographs.
This makes it easier to choose photos for reprints and enlargements.
________________________________________
Other film types
Older cartridge style films such as 110 and 126 are falling out
of favor, due to the higher image quality produced by compact
cameras that use 35mm or APS film.
Film sizes larger than 35mm exist for professional work. The larger
formats produce extremely sharp images, but the cameras needed
for these formats are considered too bulky and expensive for the
general public.
Film Speed
Sensitivity to light determines film speed ratings. Faster films
are able to attain correct exposure in less time than slower films.
The speed rating system, maintained by the International Standards
Organization (ISO), is most commonly expressed in multiples of
100 (100, 200, 400, 1000), though there are other values available,
such as 25 and 50. With each doubling of the film speed rating,
its sensitivity to light is also doubled. A film rated at ISO
200 requires half the exposure time as one at ISO 100, but twice
as much time as an ISO 400 film (assuming all other values, such
as ambient light and the camera's aperture setting remain constant).
Faster films are more versatile than slower films, because they
can be used in low light conditions where a flash is impractical.
They are also ideal for capturing action shots, where you need
a fast shutter speed to freeze the action (such as in a swimmer's
dive or an auto race).
Slower films have a finer grain and are therefore capable of producing
photos of greater detail. These films are ideal for indoor portraits
where a flash will be used, or for shooting outdoors in bright
sunlight. Enlargements can be made with less quality loss than
would be the case with a faster film, which tends to look grainy
with enlargement.
Exposure
The term "exposure" refers to exposing the film in the
camera to light. Proper exposure occurs when the correct amount
of light is focused on the film for a set amount of time. The
three main camera functions that contribute to exposure are shutter
speed, focus, and aperture. Most cameras, whether analog or digital,
will automatically control all three for correct exposure. Certain
compact and digital cameras offer some manual control, and all
SLR's offer the photographer the option of complete manual control
over exposure settings.
________________________________________
Shutter Speed
Shutter speed refers to the time the shutter remains open to expose
the film to light from the lens. By today's standards, the pioneering
days of photography produced film that was not very sensitive
to light. Exposure times were unavoidably long, lasting up to
a few minutes even in daylight. Some modern films are extremely
sensitive to light, offering the photographer great latitude in
composing a shot. Even so, we do not usually use the fastest film
possible, because films with lower ISO ratings are better suited
to bright light and offer sharper images.
The shutter speeds on today's cameras range from 30 seconds up
to 1/3000 second, with some SLR models offering even higher speeds.
The higher shutter speeds are generally used in bright conditions,
or if you want to freeze the action in a motion shot. Slower shutter
speeds are necessary in low light conditions, or if you wish to
emphasize motion by having an object blur by the frame. Exposure
times of several seconds or even longer is possible if the "B"
setting on the camera's shutter control is used. This allows the
photographer to capture interesting shots in low light conditions,
such as the blur of a car's lights on a dark street, or tracking
the path of stars in the night sky.
For lower shutter speeds it is best to use a tripod to avoid unwanted
blur caused by camera shake.
Flash photography requires a fixed shutter speed, usually 1/60
or 1/125 second, with some fuller-featured SLRs operating at 1/250
second. This ensures proper synchronization between the light
of the flash and the opening of the shutter. If your camera offers
adjustable shutter speed (as with an SLR), the value is usually
marked in red.
________________________________________
Focus
All compact and digital cameras and most SLR's employ some form
of autofocus. The focusing process is usually accomplished by
electronically comparing two views of the same scene, using mirrors.
The lens is shifted until the two views match in contrast and
pattern, which means the image is in focus. Autofocus relieves
the photographer of focusing manually, and is especially useful
when taking quick, spur of the moment photographs.
Most autofocus systems do a good job of bringing the scene into
focus, but they are not foolproof. If the shot involves a predominant
object that is not the primary subject of interest, they can focus
on that object instead of the true subject of interest. This can
occur when the subject you wish to focus on is not in the center
of the frame, or if another object is closer to the camera. To
correct this, some cameras allow you to focus on the subject while
it is in the center of the frame, lock focus, and then frame the
shot as desired. This maintains the focus setting until after
the picture is taken.
SLR cameras have the option of manual focus, so the photographer
can focus on any part of the frame without the risk of a miss-focus
by the autofocus system. There are usually focussing aids built
into the camera to help the user focus. These can include a prism
ring (which shimmers when the scene is out of focus), a split
circle inside the ring (which shows objects out of alignment when
not in focus), or directional arrows (which light to tell the
user which way to turn the lens for focussing).
________________________________________
Aperture
The aperture acts like the iris of the eye, opening or closing
to let in more or less light. As such, it has control over two
aspects of the photographs appearance. First, the change in the
amount of light entering the lens alters the exposure. Second,
changing the size of the aperture affects the depth of field;
the distance, in front of or behind the subject, in which objects
remain in focus.
For SLR cameras, a ring on the lens lets you adjust the aperture.
The aperture value, or "f-stop," is expressed as a fraction
of the focal length of the lens. The lens focal length is expressed
in millimeters, with 50mm being the focal length of a standard
lens. Focal lengths above 50mm are considered telephoto, with
the most common lenses offering a variable zoom between 85 and
200mm. Lenses of 300mm and beyond are available. Values less than
50mm are considered wide angle, with 28 and 35mm being the most
common.
The aperture ring of a typical 50mm lens has the following values
etched onto it: 1.4, 2.0, 2.8, 4, 5.6, 8, 11, 16, and 22. Each
marked aperture is referred to as a 'stop,' and since aperture
stops are measured as a fraction of the focal length, these stops
are called f-stops. Because the settings are fractions, f/2.0
is ½, f/4.0 is ¼, etc. Therefore, as the numbers
on the scale increase, the aperture is reduced. A 50mm lens set
at f/2.0 will have an aperture diameter of 25mm, while at f/5.6
will have a diameter of approximately 9mm. Each 'increase' in
the number scale of the aperture ring reduces the amount of light
entering the lens by half.
________________________________________
Depth of Field
Adjusting the aperture also has the benefit of altering the depth
of field, or the range of distance that objects remain in focus.
Reducing the aperture (allowing less light to strike the film)
will lengthen the depth of field. Increasing the aperture (allowing
more light to strike the film) will shorten the depth of field.
The depth of field is also affected by the focal distance and
the focal length of the lens. When the lens is focused on a subject
that is far away (at least several metres), the depth of field
will increase. Using a lens with a shorter focal length will have
the same effect. Conversely, photographing a subject nearby and
using a lens with a longer focal length will shorten the depth
of field.
Using a wide-angle lens in bright sunlight (aperture is small),
the area in focus may extend from just a few inches in front of
the lens to the horizon. At its closest focus, in low light levels
(aperture is large), a telephoto lens may be in focus through
only half an inch or less.
The ability to adjust the depth of field is useful for many types
of photography. Outdoor portraits, for example, benefit from a
short depth of field. With the subject in focus and the background
out of focus, distractions are de-emphasized, with the subject
given greater importance. For other photographs, you may wish
the entire scene to be in focus.
Lighting your Subject
The lighting possibilities are virtually limitless in photography,
but the amount of control you have over the lighting conditions
depends on your location and your resources. If you are shooting
indoors, you likely have the choice of shooting with or without
a flash, near a window, lamp, or overhead light, or you may have
access to specialized lamps and reflectors. Outdoor lighting is
more dependent on the weather conditions (i.e. sunny, overcast,
dawn, high noon, dusk, etc.), but you still have the option of
shooting in the shade or in the open, or towards or away from
the sun.
The best time of day for outdoor photography is in the early morning
or late afternoon. The morning light is softer, casting longer
shadows, and enhancing your subjects with a warm, rosy glow. Just
after sunset the colors will be intensified by the sunlight shining
up at the sky. Midday is less pleasing, when the strong sun casts
harsh shadows, increasing contrast.
No matter the time of day or the location, you can dramatically
change the tone of the photograph simply by shifting the illumination
of your subject. Frontlighting the subject will provide even lighting,
while lighting from the side will enhance the three dimensional
qualities of the subject. Backlighting can produce a pleasing
effect, but may require some practice to get the result you want.
When not done properly, the subject may appear too dark as the
camera sets the exposure to match the surrounding light. To correct
this, approach the subject and take an exposure reading with the
camera. Next, "lock" the exposure setting values (you
may need to place your SLR in manual mode for this). Step back
from the subject, and take the photograph using the exposure settings
obtained from the reading. If you do not follow this procedure,
the subject will appear as a dark silhouette, which in itself
can be a very pleasing effect.
Don't be reluctant to photograph outdoors if it is not a sunny
day. The even, soft light of an overcast sky is ideal for portraits,
producing soft shadow that can flatten your subject. This type
of lighting can give a cool blue cast to your photos.
________________________________________
Using a flash
Very fast film (such as ISO 1000) may be used without a flash
even in low light conditions, although the prints may look grainy.
In low light conditions with a slower film speed, it is necessary
to use a flash for correct exposure. However, photographs taken
with a built in flash can sometimes look harsh if there is no
other light source. This effect can be seen in passport photos,
or outdoor night shots. If other light sources are available,
such as a living room lamp, they can soften the flash effect.
Some flash attachments for SLR's have adjustable aim, where you
can bounce the light off a ceiling or wall. This results in a
more natural light appearance. In cases such as this, the light
has further to travel than if it were aimed directly at the subject.
The aperture should therefore be opened to compensate for the
reduced amount of light reaching the subject. Using this flash
technique can eliminate the risk of 'red-eye' in your subject.
'Red eye' is a common problem with flash photography. It is caused
by light from the flash reflecting off the blood vessels in the
subject's retina. Because their pupil will be larger in a room
with dim light, the subject's eyes will reflect more of the bright
light from the flash. Some cameras feature a red eye reduction
mode, whereby a prelight or multi-flash is activated, to reduce
the size of the subject's pupil in preparation for the regular
flash and exposure an instant later.
Remember that the light from a flash will reflect off shiny surfaces
such as water or glass. When shooting through a window, try shooting
the subject from an angle to reduce the amount of direct reflected
light. Otherwise, the reflected glare may ruin what might have
been a good photo.
When taking multiple flash photographs, wait for the flash to
recycle and the red 'flash ready' light to go on before you take
another photo.
Composition
Contrast
When trying to emphasize a subject, it is best not to photograph
it against a cluttered background. Compare a photo of someone
taken at an amusement park, with dozens of people in the background,
with a portrait. The portrait has a very subdued background that
lets the observer concentrate on the subject. This is not to say
that you should try to make the background as plain as possible.
Other people and objects in the background can make the photo
more interesting, but taking a moment to think of how the photo
will look will give you the chance to improve its composition.
Even in the amusement park example, the photographer can try to
find a less cluttered background to improve the contrast of the
photo. Another method would be to 'crop' the photo, so that the
subject fills more of the frame. The subject can also be emphasized
using an exposure control such as selective focus (depth of field).
________________________________________
Rule of thirds
When framing your photo, it is usually best not to have the subject
exactly in the center of the frame. A subject that is off-center
encourages the eye to explore the photograph. Following the rule
of thirds can help you compose a more artistic looking photo.
Mentally divide the scene into a grid, like a tic-tac-toe pattern.
This will consist of two vertical and two horizontal lines. For
photographing the horizon, align the horizon along the top or
bottom line, depending on whether you want more of the sky or
ground in the photo. You should end up with a photo that is proportioned
with two-thirds sky or land (depending on the one you wish to
emphasize), which is much more pleasing to the eye than having
the scene split evenly.
With vertical subjects such as a people, trees, buildings, and
monuments, align them with the left or right imaginary line. When
photographing people, have the person face slightly inward, towards
the center of the scene.
Experiment with placing the subject at the intersection point
of the lines, which are strong positions for your center of interest.
With some compositions, you can utilize both the vertical and
horizontal lines and intersection points.
________________________________________
Framing your Subject
A subject is framed if the photographer is able to include and
crop surrounding objects so that the resulting lines and shapes
lead to the subject. For example, you could take a photograph
through a wooden fence overlooking a horse in a farmer's field.
The fence will be cropped, so that not much of it is visible,
because its role in the photo is to frame the horse in the field.
You can follow the rule of thirds here as well, having the horse
slightly offset from the center of the frame.
________________________________________
Lines and Curves
Lines and curves present in your photo, whether in the subject
itself or in the area leading to the subject, lend a pleasing
aesthetic quality to the scene. As in the rule of thirds, the
eye is naturally drawn to asymmetry, following the lines and curves
to examine the scene. This can add interest to an otherwise simple
image and can emphasize a particular feel in the subject.
________________________________________
Point of view
When you look up at a large object such as a building or statue,
the object conveys a message of dominance and power. Conversely,
when looking down upon a subject, such as small children or pets,
the message is more deferential or humble. Try taking photographs
of these subjects at their eye level for a different, perhaps
more realistic perspective. You will notice a difference.
Experiment by shooting buildings from a distance using a telephoto
lens, and then shooting upwards from the structure's base. Each
view will give you a vastly different perspective.
Photography Tips
Taking good photographs depends more upon a person's technique
than on the camera they use. By following a few simple steps,
anyone can get the most from their camera.
Keep your camera's lens clean by using a lint-free cloth.
When it is time to take the photograph, take a firm stance, hold
your breath, and squeeze the shutter gently. This will help prevent
camera shake, which can result in a slightly blurred photo.
Use a tripod or monopod to hold the camera steady for slower shutter
speeds.
If your photos sometimes appear blurry, and you are certain the
camera was held steady for the shot, you may be unknowingly obscuring
the autofocus windows. If your fingers, hair, camera strap, etc.
are in front of these windows near the flash, you could be shutting
down the autofocus system.
If you know you will be taking fast action photos, try shooting
with film speeds of 200, 400 or higher to allow for faster shutter
speeds.
When photographing running water, slower speed films will help
to blur the water's movement giving the photo a feeling of motion.
Remember to turn your camera and take vertical shots when conditions
call for it, such as photographing people or buildings, when you
want all of the subject in the shot.
|
