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Researched by Carmelle S.
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Research Summary
Cameras and Photography
A camera is a light tight box with a small hole or hole with lens on
one side. It has film on the opposite side of the hole or lens on
one side. On the other side there is the film. Each camera has a
hole called an aperture. The camera has a viewfinder to see what
you are taking a picture of. On different cameras there are
different viewing systems.
Shutter
The shutter controls the length of time of the exposure. In early
photography, exposures lasted several minutes or hours. A popular
design was a moving blade with a hole cut in it. These shutters were
simple affairs. They were mostly put between the lens elements, so
they could be small. When the shutter release was pressed, it moved
a cross behind the lens letting light reach the film while the hole was
in the light path. Improvement in light sensitivity of the film meant
shorter exposures could be made. Early this century the lens or leaf
shutter became the most common type of shutter.
Although they are good in common compact cameras, they aren't good
for reflex viewing systems. The photographer can't see through the
viewfinder until the exposure is made because the shutter is closed.
The problem was solved by placing the shutter in the camera body.
These shutters are known as focal plane shutters and are used in 35 mm
SLRs today. Focal plane shutters are a pair of metal blinds placed right
behind the reflex viewing mirror, in front of the film. When the
shutter release button is pressed, the mirror flips up and the two blinds
move across the film. The film is exposed in a short time between
the first blind moving out of the light path and the second blind is blocking
the light
Focal plane shutters can go to very fast exposures so they are good
for freezing. Cameras such as the Nikon F 801 and the Minolta 8000I
have maximum shutter speeds of 1/8000 second. To get these fast shutter
speeds the second blind starts moving before the first blind is finished
Moving. This means at fast shutter speeds, the shutter is never
fully open.
Diaphragm
The diaphragm is an adjustable hole inside the lens. The aperture controls
the diaphragm. It is measured in f. numbers, or "f-stops."
The sequence, f/2.8, f/4, f/5.6, f/8, f/11, f/16 is usually marked on the
lens barrel of single lens. More light is let in when the f-stop
number is lower. F/16 is the smallest opening; it lets the least
amount of light in.
In the early days the intensity of light entering the camera was controlled
by inserting thin plats of metal with holes, different sizes called "stops."
They were put into the lens barrel. Today, it is built in the middle of
the lens elements. Early SLR cameras had problems because the photographer
looked through the lens. The image would be very dim when the aperture
was small. This meant that the photographer would have to look at the object
at the biggest aperture before taking the picture. Today this is
done automatically. The viewfinder shows the scene at the biggest
aperture, no matter how big it is set. The instant the shutter release
is depressed, an electronic signal is sent to the diaphragm, to set the
aperture required.
Lens
Camera lens bend the light waves onto the film. The simplest
type of lens is a single piece of glass with curved sides. These
lenses are used in the least expensive cameras, but they are effected in
numbers of optical errors called, "aberrations." More advanced modern
lenses are with something like eight pieces of glass called, "elements."
The elements are different shapes so the light waves are bent both in and
out before they are brought to focus. This helps prevent problems in pictures.
The danger with having many elements is that they will reduce the amount
of light reaching the film. Some light can be reflected off the glass
surface and can't become focused at all. So to prevent the loss of
light, the elements are coated with special chemicals. For good pictures,
the lens must be able to focus your subject. Early cameras and modern
point -and-shot cameras have lenses set a fixed distance from the film.
Different lenses have different effects. Wide-angle lens allows
more scene to be photographed. Telephoto zoom lenses take close up
pictures from far away. Fish-eye lens distorts the image, like looking
through a bowl.
Principals of Photography
In making a photograph, three stages are involved. The
first stage is to release the shutter so the light comes in through the
lens and strikes the film. The camera is involved in the first stage
only. The second stage involves developing the film in special chemicals
to make the negatives. The image in a negative is usually reversed.
The dark areas are light and the light areas are dark. The third
stage is printing the negative onto photographic paper to make a photograph.
The photograph will have its original image.
Two important things that the camera must accomplish are
to focus the light waves with the lens and secondly, to control the amount
of light that strikes the film and how long the film is exposed to light.
The diaphragm and the shutter control the exposure.
Focusing with the lens makes the image sharper and not blurred.
You don't want the photograph to be over exposed or under exposed or the
image will be too bright or too dark.
Taking Pictures of Animals
Animals have long been a subject of photography. People
have taken pictures of animals just for fun. Other people study animals
and take pictures of them to record what they observed or to show other
people. For example bird watchers take pictures of all different kinds
of birds they see. They can identify what kind of species they have
seen in the wild. Other people take pictures of animals under the
ocean like during the expedition for the Giant Squid. Some professional
photographers risk great danger to take pictures of dangerous animals like
lions, poisonous snakes, or sharks.
There are some techniques to take good pictures of animals.
Using high-speed film and high shutter speed reduces blurred images of
moving animals, like dolphins, birds, and cheetahs. Telephoto zoom
lenses come in handy when taking pictures of dangerous animals from a safe
distance.
A tripod and time lapse photography can be used to record things
that happen slowly, like a beaver making its dam. Time lapse photography
involves the camera automatically taking pictures at pre-arranged intervals
over a long period of time. The photographer doesn't even have to
be there.
Types of Cameras
There are several types of cameras like the SLR or Single Lens
Reflex, digital cameras, stereo cameras, the point-and-shot cameras, zoom
cameras the instant print cameras, 110 mm cameras, and the disposable camera.
Point-and-shot cameras are also popular, because they also use
35-mm film cassettes. Most of these focus and set the aperture automatically.
Many of the point-and-shot cameras have fixed lens and don't allow focusing.
Some have zoom lens and built in flashes that pop up. Most point-and-shot
cameras have the viewing system separate from the lens. They have
similar, but not the same, view as the lens. Although they are not
versatile like the SLR cameras, they are lighter and easier to use and
mostly less expensive.
The SLR cameras make negatives 35 mm wide. One reason why
the SLR cameras are popular is their lenses can be changed easily and quickly.
SLRs use a mirror and a prism to allow you to look at what the lens see.
Detachable units that provide flash are put on the cameras "hotshoe."
SLRs also use focal plane shutters.
Instant print cameras are usually larger than 35mm cameras.
They generally have fixed lens. Also automatic focus lens as well
as a fixed exposure time. A big advantage is that they use special
film that makes the prints in seconds. How does the instant print
camera make its pictures so fast? The chemicals for developing are
in a bulge at the end of the film. After the pictures are taken,
the picture rolls out. The chemicals are then squeezed out over the
paper. As the chemicals work, the picture develops.
Small inexpensive 110-mm cameras that fit in pockets usually
allow no adjustments. They're easy to use and load. The 110-mm
camera's film come in cartridges that drop neatly into the back of the
camera. You will not have to thread the tail end of the film, called
the, " leader" when locking the camera. You don't have to rewind
the film also. The problem of the 110-mm camera is that the negative
is so small it limits the size and quality of the final. When it
is enlarged larger than the snapshot size, the images turn fuzzy and the
color is usually washed out.
Some inexpensive cameras called," disposable cameras."
Are designed for use only once and can be thrown away after.
Digital cameras are cameras that allow you to see your picture
on a screen or a computer monitor. You can print the picture from
the computer, but the quality of the picture isn't the same as the film
cameras. Sometimes it needs special software.
Stereo cameras make images with depth. Stereo cameras take
two pictures at the same time of the same object at the same time.
The most important, recent development in compact camera technology
is the zoom camera. The first model was the Zoom 70, made by the
Japanese company, Pentax. They launched it at 1987. The camera
had zoom lens. The lenses allow the photographer to select an area
of the subject and focus the picture without moving closer or farther away.
Zooming the lens forward or backward has the same effect as if the photographer
moves close or far from the subject. Zoom cameras have this type
built into the camera body. Although there are a few manual cameras,
most zoom cameras have a tiny motor inside it to move the zoom lens backward
and forward.
Equipment
There is certain equipment that you need to make good pictures.
You would need a tripod, a filter, a camera bag, a light meter, and a motor
drive.
A tripod is a portable, three-legged stand to attach a camera on.
It keeps the camera steady when some ones shooting with normal lens at
shutter speeds 1/60 or slower. If your are using lens of 135-mm or
longer, use a tripod at speeds slower than 125. As you increase the
size of the shutter speed and the size of the lens, for example, if your
using 200-mm lens then use a shutter seed slower then 250.
A camera bag is a padded bag that helps protect the equipment,
camera, and makes it easier to carry. Many bags have extra pockets
to hold the film and the lenses. They also have padded carrying straps.
Filters are used in the cameras to protect the lens and make
special effects. UV filters are used more often than any other filters
these clear looking filters absorbs ultraviolet radiation that can appear
as haze on the pictures. Photographers use UV filters to protect
the camera lenses from dust, scratches, and breakage. Polarizing
filters are also popular. In addition to reducing glare, they can
accentuate the clouds, cut down on reflections, and bring the skies blue
color. Without a filter the sky and the clouds might have blended
together too much. When shooting with black-and-white film, you can
use a yellow or red filter to darken the clouds. Other types of filters
soften images and make special effects.
Most 35-mm cameras have built-in light meters that set or recommend
the proper exposure. In many adjustable cameras the exposure setting,
a combination of aperture and shutter speed-is displayed on the viewfinder.
Many of these cameras use a needle to indicate the right exposure.
When the needle was centered in the brackets the exposure was right.
The image was over exposed when the needle was up. The image might
be washed out. The exposure was to low when the needle was down.
Details in the image would disappear if the exposure is to dark or to bright.
Motor drives or power winders advance the film automatically
and quickly after the shutter release button was pushed. They were
very useful for shooting fast action sports or other things like that.
Film
Film comes in rolls or plates of plastic film. It could
be in color or in black-and-white.
Developing Your Own Film
Developing and printing isn’t too hard once someone has shown you.
Many different kinds of chemicals are needed to develop and print pictures.
To work with exposed film, you’d have to work in a dark area because if
light is exposed to the film, the image already there would disappear.
Developing black-and-white film is the same no matter what brand
of developing chemicals you use. How ever, time and temperatures
vary with each brand. Always read the instructions that come with
the chemicals. Prepare the chemicals according to the packets instructions.
By running hot or cold water on the solutions adjusts the temperatures
of the chemicals to within one degree of the recommended reading, which
is an usually68 degree Fahrenheit.
In a completely dark room, open the film cassettes with a can
opener, cut off the leader, and load the film onto the film reel.
Insert the film reel into the developing tank and close the lid.
Once the lid is properly closed you can turn on the lights. You can
also use a changing bag. Put the film, scissors, film reels, can
opener, tank, and the lid into the bag. Then insert your arms into
the sleeves of the bag and follow the same steps as in the light tight
room. Before attempting to load a special load of film, you should
practice in the light with a spare roll of film.
Once the film is loaded properly, pour the developer into the
tank. Then seal the second lid and set the timer. Gently shake
the tank for 30 seconds by holding the tank in your hand and rotating your
wrist back and forth. You also need to shake the tank every minute
the developer is in the tank for ten seconds. Pour out the developer
at the right time. Pour the stop bath solution into the tank, it stops
the developer from acting. After 30 seconds, drain and discard the
chemical down the sink. Next, pour the fixer, which fixes the image
on the film and makes the image permanent, and shake the tank for 10 seconds
every minute. Drain the fixer when the time is up and dispose it
as directed. Once the fixer is drained you may expose the film to
light. Open the lid of the tank and wash the film. Then place
the tank under a faucet of running water and let the water run through
it. Wash the film for 5 minutes and then add hypo-clearing agent
to get rid of the fixer. Wash the film for an additional 15 minutes
and if your not using the hypo-clearing agent wash it for 30 minutes.
Pour in a wetting agent to prevent water spots from forming on the film
when it dries, like Photoflo, into the tank and drain after 30 seconds.
Then unroll the film and hang it to dry. Make sure the film doesn’t
touch the walls or other rolls or anything else. Once the film is
dry cut it into stripes of 5 or 6 frames and slip into protective sleeves.
History of Photography
It was known for centuries that an image of a scene can be made by
allowing light to pass through a small hole or glass lens. In the
seventeenth century, artists using portable boxes fitted with lens and
a mirror helped them work. The light passed through the lens and
focused into an image (upside down), reflected off the mirror onto the
drawing board, so the artist could trace the image. The device was
known as "camera obscura", Meaning darkened room, or a pinhole camera.
Many different designs were used.
Photography was said to be made in 1839, but the first real camera
was made 15 years earlier by a French named, Nicephore Niepce. He
used -coated sheet of copper that was coated with light sensitive
material in a camera obscura. The silver-coated sheet of copper was
sensitized by a treatment with iodine vapor, forming a coating of light
sensitive silver iodine. He managed to record a view from a window.
The exposure took 8 hours.
In 1893, photography became practical. It was Frenchman,
Louis Daguerre and an Englishman William Henry Fox Talbot who revealed
to the world their different systems in recording permanent images.
The methods were different, but the cameras were similar. Generally
the cameras were large and wooden boxes with a simple lens. It was
supported on a tripod. It had no shutters or diaphragms because many
minutes of exposure were required for a recognizable picture to be made.
The lens can be uncovered and covered when the exposure was complete.
The equipment and methods used in the early photography were
very different from now. Life was very uncomfortable for people who
rushed to have their portraits taken in fashionable new photographic studios.
Their necks were held by clamps to stop them from moving and blurring the
picture. The negatives were much larger back then, usually 5by 3inches.
The six of the sensitive plate and the finished picture were much larger.
The cameras were also larger and more awkward to use.
We are now used to smaller cameras. Equipment that was
very similar to these are still used by photographers today. View
or sheet film cameras are made up of 2 panels. They are connected
with flexible, lightproof leather bellows, which are mounted on the third
panel. The front panel has the lens, shutter, and the diaphragm.
The back panel has a ground-glass screen where the photographer can view
the subject. Moving the 2 panels closer or farther to focus the image.
When the photographer is ready, a single sheet of film is loaded in the
back panel. The shutter is released to let the light in. The
camera must be reloaded every time a new picture is taken. In present
times, these cameras are primitive, or difficult to use. The qualities
of the pictures are the best kind. There is hardly any grain.
This is why sheet film cameras are used for billboards.
Louis Daguerre made a plate called Daguerreotype. The Daguerreotype
plate was exposed in a camera and then developed with mercury fumes at
temperatures of 120 degrees Fahrenheit (50 degrees c ). The exposed
areas absorbed the mercury atoms and highlighted the image. The image
was superbly fine in detail. This process became popular and developed
into a growing business in England and the United States.
Focal Length
The number, which is stamped or painted on the inside of the
rim or on the outside of the lens, is called the focal length of the lens.
Focal length is the distance from the center of the outside of the lens
elements to the point where the light rays meet inside the camera.
The focal length number also describes how much wide of area the lens sees.
SLR cameras have lens with low focal length numbers.
24-mm, 28-mm, and 35-mm are usually wide-angle lenses.
They take a wider view than 50-mm lens. Wide-angle lenses are good
for shooting groups of people and large objects in small places.
When using wide-angle lens, there is light distortion. The distortion
is most noticeable in pictures of buildings, roadways, and other subjects
with parallel lines.
Telephoto zoom lenses generally have 85-mm focal length or longer
have narrower views than the standard wide-angle lenses. While the
view is narrower, the image is captured on the film and turns up magnified
and the objects seem closer.
Telephoto lenses between 85-mm through 105-mm are sometimes referred
to "portrait lenses." The common ranges of telephoto zoom lens are
8-200-mm and 35-135-mm.
Focus
To get good sharp images on the film, the lens need to be focused.
With automatic, fixed focused cameras the focusing is done for you.
With a manual camera it’s focused by turning the ring on the lens.
It moves the lens elements further away or closer to the film plane.
When the elements move far away from the film the subjects close to the
lens get focused. When the elements are moved as tight as possible
the distant objects will be sharp and the close objects will be blurred.
The most adjustable focus camera has a viewing screen that is visible through
the viewfinder. In many SLR cameras, there are two small half circles
visible in the middle of the viewfinder. When the lens are focused,
the half circles match at the center and when it is unfocused the two circles
split apart.
Depth of Field
How are you sure how much of a scene will be in focus? By using
a depth of field scale. The scale is located on many interchangeable
lenses used with35-mm cameras.
Depth of field is the depth of distance of focus within the field
of view. It indicates how much of a scene is in acceptable focus.
There is a direct relation ship with the aperture of the lens. The
smaller the aperture the greater the depth of field or area in focus.
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