Basics of Photography: Taking Better Photos by Understanding How Your Digital Camera Works
We spent the last week learning all about the basics of photography,
from the way your camera works to composing your photos to editing them
in post. Here's the complete guide, along with a PDF of all the lessons
and some additional resources fo learning more.
With
so many cameras available, figuring out how all the specifications and
options translate into your everyday use is complicated. For our first
lesson in the Basics of Photography, we're going to learn how cameras
work and make sense of what that means in terms of choosing a camera to
buy and how it affects your photographs.
The Parts
Your camera
is made up of many parts, but there are a few in particular that we
want to look at as they are the most important. We'll go into much more
detail in a bit, but here's a basic overview of the parts we're going to
look at:
- The body
is the housing for your camera. While it has little effect on the
quality of your photos, it does affect things like ease of use and
comfort.
- The lens
is the eye of the camera, and it's a very complex instrument. Different
lenses can provide many different features, so it's important to know
the differences between them. In future lessons, we'll also discuss how
lenses work and how that affects your photographs.
- The sensor
is basically the digital equivalent of film, in the sense that—like
film—the sensor is exposed to light that comes through the lens and it
records that exposure. The exposure is then processed and saved to flash
memory (generally an SD or Compact Flash card). The caliber and size of
the sensor are also very important, as these things significantly
impact the quality of your photos.
- The flash card
is where you save your images, and it's a component most people don't
think about too much when buying a camera, aside from choosing an amount
of storage that suits their needs. Flash cards range in read and write
speeds as well, however, and a slow cards can significantly degrade your
camera's performance. We'll take a look at what card classes mean and
the minimum speed you need for different purposes.
- The battery
matters in a camera just like any other electronic device. While this
is a simple part to understand, we'll dive into it a little more deeply
to figure out actual, practical battery life for cameras and when
cameras with less-powerful batteries may be a better option.
The Body
Camera
body design affects the user in a couple of ways. First, the size of
the body can have a major impact on comfort when being held and used.
Small hands will have difficulty with large bodies and, conversely,
large hands will have difficulty with small bodies. Before purchasing a
camera, it's a good idea to hold it and take a few pictures so you know
if you'll find it comfortable to use with regularity.
Size often
impacts the location of buttons, dials, and other parts of the hardware
you'll need to touch and press to operate your camera. The positioning
on small point-and-shoot cameras tends to be fairly simple, because
there are fewer hardware controls, but the moment you step up to a
smaller DSLR (such as Canon's
Rebel series)
that number increases significantly. On higher-end DSLRs, the extra
space tends to ensure your hands will always be able to reach and easily
access the most important controls. This is a generalization, however,
and you'll want to test them out for yourself. When you do, adjust
camera settings and see what all the buttons do
in manual mode
(so you're aware of their full capabilities). If it feels uncomfortable
or awkward to make adjustments you'll make often, you may want to
consider a different model.
While most
cameras are fairly similar, the little differences in body design can
have a significant impact on their ease of use. While you can generally
judge a camera's abilities without ever using it, you'll need to test it
out yourself to make sure it feels right.
The Lens
Certain
types of lenses are better for certain situations, so it's important to
know their classifications and differences. The first thing worth
noting is the difference between zoom lenses and prime lenses.
Zoom lenses—as you can probably guess—let you zoom in and out. While
they have that advantage, they're generally more expensive, heavier, and
larger. Prime lenses, on the other hand, do not allow you to
zoom, but they're often cheaper, lighter, and smaller. In many cases,
prime lenses will provide sharper images than zoom lenses at lower price
points. When you start paying thousands of dollars for lenses, lens
performance tends to be a little more equal.
The next thing you want to understand is the difference between
wide-angle,
standard,
medium,
telephoto, and
ultra telephoto
lenses. These terms are all based on a lens' focal length, which is a
complex definition that's beyond the scope of this lesson (if curiosity
compels you,
read about it on Wikipedia).
What you need to know is that focal length is measured in millimeters
(mm) and you can think of it like the amount of magnification. A low
number is like being zoomed really far out, and a high number really far
in. Here's what you need to know about each type:
Wide-angle lenses
are essentially any lenses with a focal length of up to 35mm. The wider
the lens (and lower the focal length), the more the lens can see.
Fisheye lenses are extremely wide and often have a rating of around
8-10mm. A regular wide-angle lens is generally around 14-28mm. As you
can see from the photo on the left, wide angle lenses capture more stuff
in the frame. They also distort space, increasing depth and making it
look more spherical. This can be both a wanted and unwanted effect,
depending on the circumstances. Some wide-angle lenses include
technology that corrects this distortion, but those lenses are almost
always significantly more expensive.
Standard lenses
are generally between 35-50mm and tend to most closely represent space
the way the human eye sees it. Wide-angle lenses tend to distort space
and add the appearance of more depth. Telephoto lenses flatten space.
Standard lenses are the middle ground and produce images that look
realistic to most people. A 50mm prime lens is often the cheapest lens
you can buy with a level of quality that rivals zoom lenses priced at
several hundred dollars more. Standards are the most versatile lenses
because they're a good compromise between the more extreme types, but
they're often useless when you're in a small space and need to go wide
or are far away from your subject and need the magnification power of a
telephoto.
Medium lenses
generally fall into the range of 60-100mm and are generally not a type
you'll want as a prime unless you have a specific purpose in mind (some
prefer 60mm and 85mm prime lenses for portraits, for example). This
range is often encompassed by zoom lenses, and that's generally where
you'll want it. Many standard zoom lenses start as wide as 28mm and end
up at 70mm, at least. A good standard zoom will encompass this range.
Telephoto lenses
are what you want for zooming in really far. Pretty much anything over
100mm is considered a telephoto lens, and anything over 400mm is
considered an ultra telephoto lens. While telephoto lenses can
magnify an image many times over, and are necessary when you can't get
close to your subject, they're both heavy, are more subject to motion
blur (as a result of camera movement), and do not perform as well in low
light. You will find some options that are compact, come with image
stabilization (to prevent motion blur), and offer wider apertures (to
perform better in low light), but all of these features increase their
cost significantly.
The Sensor and CPU
The
sensor is the part of your camera that captures the light exposure
filtered through the lens. For our intents and purposes, we're just
going to call this the image. The way the sensor was produced, and how
large or small it is, has a pretty big effect on the end result: your
photograph.
First of
all, the size of the sensors matters. Compact point-and-shoot cameras
have very small sensors and the difference in size between them is a
smaller factor when choosing a camera. When it comes to cameras with
interchangeable lenses, which include DSLRs and
MILC/CSC/EVIL
cameras (which are basically compact, mirrorless DSLR-like cameras that
often—but not always—have smaller sensors), sensor size has a greater
impact. Generally larger sensors provide better low-light performance,
greater control over depth of field, and produce higher resolution
images with less noise than a smaller sensor.
The
majority of DSLRs have a sensor size most commonly known as APS-C. An
APS-C sensor is about half the size of a frame of 35mm film and
generally magnifies all lenses by a factor of 1.6x. This means that
using a 35mm lens on a DSLR with an APS-C sensor is basically the same
as using a 56mm lens on a regular 35mm camera. This is good news for
telephoto lenses but bad news for wide angle, as every lens isn't as
wide as advertised when placed on an APS-C-based camera. A 10mm fish eye
lens will produce photos like a 16mm wide-angle lens. It's not a major
downside for most people, but it's important to know.
Some higher-end DSLRs contain full-frame sensors, such as the popular
Canon 5D Mark II,
which is equivalent to the size of a frame of 35mm film. Full-frame
sensor DSLRs have the previously mentioned benefits that come with large
sensors, but also are
not subject to the 1.6x magnification
like you'll find with APS-C sensors. Basically, a full-frame sensor DSLR
is about as close as you're going to get to 35mm film with a digital
camera.
While
sensor design is very relevant to the image quality, and the only way
you're going to be able to judge that quality for certain is to see or
produce sample images, you should pay attention to the sensor's
megapixel rating. In general, the more megapixels packed into a sensor
the more noise you'll find in a given image. This is why you don't
necessarily want to choose a camera with a high megapixel
rating—especially when a camera has a smaller sensor. For most people,
even a 6.3 megapixel camera is sufficient, but anywhere from 8-10 should
be more than sufficient. The point is, don't just buy one camera over
the other because it has a higher megapixel count. It may produce
noisier, less-desirable results so you should always test first.
The Flash Card
Flash
cards come in all different sizes, but they come in different speeds as
well. Nowadays you're most likely to end up with an
SD or
CompactFlash
card. The speed of your flash card is important because most cameras
nowadays are very fast. You can take many images in rapid succession,
but if your card has a slow write speed it can't keep up. For SD cards
you'll be best served by a Class 6 card. For CompactFlash, a card rated
at 133x should do just fine.
Many DSLRs
and compact cameras come with video capabilities, and writing this kind
of data requires a fast flash card. Class 6 SD cards will still be
enough for most point-and-shoots, but if your video-capable DSLR uses SD
cards you'll probably want a Class 10. Class 10 cards are not all
created equal, however, and some are marginally faster than Class 6. In
most cases any Class 10 should sufficient, and anything with a max write
speed of 15MB per second be more than enough. Of course, it doesn't
hurt to get a faster card and some Class 10 SD cards are capable of
write speeds twice that fast. CompactFlash cards are often used in
higher-end DSLRs because they're capable of faster speeds at a lower
cost (mainly because they're physically larger and that's easier to
achieve thanks to their size). A CompactFlash card rated 233x or higher
should handle video in most any DSLR just fine, but faster cards will
definitely make things run more smoothly.
The Battery
Most
DSLRs pack a battery that will last you all day, but compact
point-and-shoot and MILC/CSC/EVIL don't necessarily come with that
luxury. When considering something of the more compact variety, you want
to weigh both the longevity of the battery and the cost of a second
one. Sometimes you can get a better camera with poor battery life, but
the cost of an additional battery isn't very expensive. If you don't
mind charging two batteries this can be a good option.
With DSLRs
you'll often get a good battery but sometimes that battery will perform
better in certain circumstances. DSLRs do not require the use of the LCD
screen and you'll generally take pictures through the viewfinder. The
battery will last much longer when the LCD screen is not powered, so
companies will often provide two ratings for the battery life: one in
the number of photos you can take and one in the number of hours the
battery will last. The number of hours generally refers to the amount of
time the camera can be actively functioning with the LCD screen turned
on and the number of photos is simply how many pictures you can expect
to take without the aid of the LCD screen. When judging battery life for
a particular camera, be sure you know if you plan to use it more with
the LCD screen on or off first.
Other Considerations
Your
camera's processor is also important, but most are so fast these days
that it's becoming somewhat irrelevant. If it can handle more than 7 RAW
frames in succession, or 20-some JPEGs, it will never feel slow.
If your
camera comes with a flash, you may want to find out how bright it is and
test if the light it produces is sufficient. In most cases, it won't
be. If you really need a flash, you're better off with an external, so
don't be discouraged if your camera doesn't have one.