French
inventors Nicéphore Niépce and Louis Daguerre conceived photography in
the 19th century as a way to record light by shining it on photosensitive
chemical screens. In the 21st century, most photographs are taken with digital
cameras, which use sensors instead of chemicals to record images and save
them as digital files. Even the most modestly priced digital cameras can take
decent photos today, so high-quality photography is within the reach
of almost everyone.
Even
the best camera needs a good photographer behind it to take the best possible
images. You might be a budding photo pro, an ardent hobbyist, or just someone
who wants to take great photos at family gatherings and summer vacations.
In any case, it pays to know the core fundamentals of photography. While
cameras have certainly changed a lot in the last 150 years, the principles of
photography remain pretty much the same.
Put a
fresh set of batteries into your digital camera, make sure the lens cap is off
and prepare for 10 photography terms that will help you take better photos in
any situation.
Post processing
With
digital photos, your work doesn't end when the photo is taken. While Photoshop
is the most famous photo processing software package, there are dozens more can
be used to alter and manipulate photos. With practice, you can use them for a
lot more than pasting photos of your little sister's face onto zoo animals.
Beginners
can use post processing to adjust brightness, contrast and color balance. This
is an easy way to make a poor photo passable and make a good photo look great.
More advanced users can play with color channels, apply special effects or make
a composite of multiple photos. For example, if you were bracketing a shot of a
dog in front of a window, you might get one photo with the dog properly exposed
but the window too bright, and one with the window exposed but the dog too
dark. In post processing, you could combine the two for one perfectly exposed
image.
While
there's no limit to the creative things you can do with post processing
software, there's a reason this term is last on the list. Learn to shoot
excellent photos with the camera first. Then you'll have the raw materials to
do good post processing work later.
White balance
White
balance reveals an interesting difference between a camera and a
human eye: A human eye has a human brain attached. When you look at a white
object, your brain is actually interpreting the lighting cues around you and
calculating that the object is white on the fly. If the object is under a blue
light, it will really look blue, but your brain compensates for the color
difference, so you'll see it as white. The camera does no such compensating
unless you force it to do so, so if a white object is under a bluish light, the
camera will record bluish pixels.
Adjusting
white balance helps force the camera to compensate for the fact that most
lighting conditions aren't perfectly white. Many indoor lights have a yellowish
tinge to them, while fluorescent lights have a bluish tint. Even natural light
is a little bluer than you might think. You can set white balance manually by
adjusting it up or down or selecting the appropriate setting, then taking some
test shots to see which ones look most natural.
Alternately,
you can use a camera's automatic white balance function. Just aim the camera at
a white object, such as a large sheet of paper (this is why news vans are
almost always white so the camera operator has an easy way to set white
balance). When you hit the white balance button, the camera will automatically
adjust to the lightning conditions.
Shutter Speed
So far
we've talked about aperture, which defines how much light gets through, and ISO
number, which determines the light sensitivity of the camera's sensor.Shutter
speed is the third part of the exposure equation. It refers to how
long the shutter remains open to allow light through. Shutter speeds are given
in fractions of a second you'll commonly shoot at 1/500.
Shutter
speed is tricky because slow shutter speeds don't just allow more light
through, they can cause blurring. The entire time the shutter is open, light is
hitting the sensor, and if an object (or the camera itself) moves during that
time, the movement will show up as a blur. If you've ever seen one of those
photographs of the stars at night showing the lines of their motion as the
Earth rotates, that image was the result of a very long shutter speed recording
the starlight over several hours.
You can
reduce blur by using a tripod to hold the camera steady when you shoot, which
lets you use slower shutter speeds, but if you're shooting sports and you don't
want blurry players, that only helps so much.
Lens
The
lens is probably the most important part of the camera. Photography is all
about capturing light, and all the light you capture passes through the lens.
On less expensive cameras, the lens is built into the camera's body.Single
lens reflex(SLR) cameras have interchangeable lenses. The camera body has a
metal ring where the lens attaches. The attachment point also has electronic
connection points so the camera can control the focus and zoom motors on the
lens.
An
important factor in choosing a lens is focus length. This generally refers to
the length of the lens itself, and is measured in millimeters. A 50 mm lens is
considered average, good for shooting subjects that are 33 to 65 feet (10 to 20
meters) from the camera. Wide angle lenses have shorter focal lengths that can
capture large panoramic scenes or large subjects that are relatively close to
you. Telephoto lenses, which can have focal lengths of hundreds of millimeters,
are basically telescopes mounted to a camera. They make far away subjects seem
closer, but with a limited field of view.
If your
camera has a zoom lens, then the focal length changes as you zoom in and out.
Remember to never use digital zoom the camera is simply enlarging the pixels
to make the subject seem closer, which reduces image quality.
ISO Number
The ISO
number is a measure of light sensitivity. It originally referred to the
sensitivity of a given type of film, and the standards for measuring were
determined by the International Standards Organization (ISO), which is where
the name comes from. In a film camera, you had to change film to change ISO.
Digital cameras allow you to change ISO through the camera's menu functions,
adjusting the sensitivity of the camera's sensor to an ISO equivalent number.
So how
does ISO work? While it measures light sensitivity, photographers refer to ISO
as the "speed" of the film or sensor. At high sensitivity, more light
is sensed within a given period of time than at low sensitivity, so high
sensitivity is considered faster. Unlike aperture, ISO settings are relatively
straightforward. Low ISO numbers indicate the least amount of light sensitivity,
while high ISO numbers are faster, more sensitive settings.
Why not
always use the highest ISO possible all the time? In film cameras, high ISO
film was grainy. We didn't escape that limitation with digital cameras, but
instead of grain, high ISO numbers introduce digital noise. One of the most
important things a photographer can learn is how to get the best quality shot
in a given lighting condition with the lowest possible ISO setting. Of course,
sporting events and other fast moving action requires high, fast ISO numbers.
Fortunately, those situations are usually brightly lit.
Focus
Focus
is a function of a camera's lens and the current aperture setting. An object
that is in focus in crisp and clear, while one that is out of focus will appear
blurry. Photographers have many ways to manipulate and adjust focus. Some
prefer to manually focus a shot using the focus ring. Point-and-shoot camera
users often rely on auto focus, which is a system that lets a
camera's sensors detect the subject's distance as a motor automatically adjusts
the focus. Auto focus is very handy, but has its limits if you're shooting
several subjects at various distances from the camera, or subjects that are
moving toward or away from the camera.
Some
advanced cameras have continuous auto focus it can actually track moving
subjects and keep them in focus no matter where they go. If one of these
cameras isn't in your budget, you can manually set your focus for a certain
distance and time your photos when the subject reaches the right place. You can
even "game" the auto focus by forcing it to focus on some object at
the proper distance, then taking the actual photo of an entirely different
subject that moves into that same distance.
Depth of field
You've
probably seen beautiful photos of flowers which are close to the camera and in
crisp focus, while the background is soft and fuzzy. That is the result of a
camera's limited depth of field. Depth of field can range from
extremely narrow (for example, a photo of a flower in which only one petal is
in focus while the rest is out of focus) to effectively infinite (such as
landscape photos where everything in the image is in crisp focus).
Depth
of field is primarily affected by the camera's aperture setting. As we
explained above, a larger aperture (which has a smaller f-stop number) will
give you a narrow depth of field, while smaller apertures (with larger f-stop
numbers) will result in a large depth of field. Depth of field is also strongly
affected by focal distance, which reflects both the kind of lens you're using
and how close the subject is to the camera. Closer subjects will have narrower
depth of field, while distant subjects can have nearly infinite depth of field.
Calculating depth of field is actually a complicated business involving
something called the Circle of Confusion. If you're not interested in the math,
just experiment with your camera and a variety of f-stop settings and subjects
to see how you can manipulate depth of field.
Flash
Flash can be an
important light source when shooting in low-light areas or unevenly lit
situations. However, even if you only shoot photos at family gatherings
with an inexpensive point-and-shoot camera, you've probably already come to
realize the limitations of the flash as a primary light source. Countless
photos with the foreground subjects "blown out" by excessive flash
and overexposure litter hard drives everywhere, leading many photographers to
try and work with as much ambient light as possible. All that said,your
camera's flash doesn't have to be your enemy.
If
you're stuck with your camera's built-in flash and no good way to increase
lighting, there are a couple of tricks for preventing flash-induced "blow
out." First, back away from the subject, zooming in slightly if necessary.
Try taping some white tissue paper over the flash to diffuse and soften it.
Many digital cameras allow you to reduce the flash intensity through the
settings menu, so try that, too. If all else fails, just stick your finger over
the flash. This is a hit-or-miss method, and the photo will be dark, but if you
experiment, you might capture the ambiance you're looking for.
Of
course, professional photographers can play a variety of tricks with flash,
from using remote flash, bouncing the flash off a reflective surface, or using
a flash in the middle of a long exposure to freeze the action. It's a very
versatile lighting tool.
Aperture/f-stop
Aperture
and f-stop are closely related terms. Aperture refers to the
opening in the lens that light shines through when a photo is taken. A larger
aperture obviously lets more light through. F-stop is simply
the nomenclature that photographers use when discussing different sizes of
aperture.
F-stops
are usually given as "f/8" or "f/22." The numbers can range
from less than one (only a few lenses and cameras are capable of f/0.95, for
instance) to f/128. A higher f-stop indicates a smaller aperture and less light
getting through. Usually, f-stops are indicated on a standard scale in which
each increase represents an aperture that allows half as much light to get
through. For example, f/8 allows half as much light through as f/5.6. While
many cameras allow for f-stops that lie in between these standard f-stop
settings, the standard scale looks like this:
f/1,
f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64, f/90,
f/128
Aperture
is extremely important because photography is all about the manipulation of
light. The proper f-stop for the lighting conditions is a major factor in the
quality of the final photograph. It's hard to give specific rules for f-stop
settings, because the right setting depends on a bunch of other factors, like
the lens you're using, the shutter speed at which you're shooting, and the
subject you're photographing. It will take some experimentation and experience
with your particular camera setup to find the aperture settings that work best
for you.
F-stops
also allow photographers to manipulate depth of field to create different
artistic effects in their photos. We'll discuss depth of field in detail later,
but for now, note that a larger aperture (which has a smaller f-stop number)
will give you a narrow depth of field, while smaller apertures (with larger
f-stop numbers) will result in a large depth of field.
Exposure
Exposure simply
refers to the amount of light recorded on the film or sensor. You want the
right amount of exposure to capture the image you see (or are trying to
create). If you shoot a daylight scene with too much light hitting an overly
high ISO sensor for too long, you'll end up with an overly bright, glaring,
unrealistic image. On the other hand, a small aperture at low ISO and short
shutter speed could make a daylight scene look dark and murky. Balancing
shutter speed, ISO and aperture to get the correct exposure is the key to great
photography. Master this juggling act and you'll be well on your way to
consistently taking great photos.
Luckily,
there's an easy way to cheat on your exposure juggling routine. It's called
bracketing. To bracket a photo manually, set your shutter speed, aperture and
ISO to where you think the proper exposure is, then take the photo. Then,
adjust your aperture or shutter speed to reduce the exposure slightly and take
that photo. Then adjust the exposure so it's slightly more than the first photo
and take that one. This series of three photos "brackets" what is,
hopefully, the proper exposure. Try to hit the sweet spot between the three to
capture the perfect image.
Most
digital cameras make this even easier with an automatic bracketing mode.
When this is turned on via the camera's settings, the camera will automatically
take three photos, with properly adjusted exposure settings, every time you
press the button.
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