Photography Information To Help You Take Better PicturesSo
you
have decided to pick up the camera and expand your photographic
horizons.
Photography basics can be overwhelming when you’re first starting out
so here
is a bit of information to outline some concepts and get you started. Its
not
hard to improve what your current camera capabilities can give you and
with a
bit of technical know how you can take stunning pictures yourself when
Fever
Shot can’t come to the rescue. Before
we
get started I just want to bring to your attention a functionality of
your
camera that most people ignore and that is the preset scene settings in
almost
every camera. Camera
producers
spend thousands of dollars in research and programming to help you
attain
better photos so instead of using ‘Auto’ find your camera scene mode
and select
the mode best suited to your environment such as ‘portrait’, ‘indoor’,
‘scenic’,
etc. Once
you
have gained a bit of confidence with the scene mode we can explore how
to use
your camera in full manual mode. In manual mode you will need to
consider many
factors but this is what makes taking photos fun and in return give you
higher
quality pictures. I will outline the following topics which are the fundamentals to photography and help you understand terminology if you wish to undertake a course in this field.
APERTURE: An
aperture is a lens opening is an f-stop. You
can
control photons by using the lens aperture (or the f-stop). The
aperture is the
size of the opening through which the photons pass. You can think of
an
f-stop as a pipe: Larger pipes let more light flow in a given period of
time,
and smaller pipes restrict the amount of light that can
pass. The aperture is a clever little
adjustable mechanism that uses a sliding set of overlapping metal
leaves to
create an opening of the desired size, as shown in Figure 2-9. To
get the right amount of
light for an exposure, you need to choose the right f-stop. To choose
the right
f-stop, you need to understand three confusing facts about f-stops: · F-stops seem to be named wrong. That is, f/2 is larger than f/4, which is larger than f/8. When the numbers get larger, the amount of light an aperture can admit gets smaller. · F-stops don’t seem to be properly proportioned. An f/2 opening lets in four times as much light as f/4, and f/4 admits four times as much as f/8. You’d think numbers like two, four, and eight would represent double (or half) as much — not four times. · F-stops
use all these weird intermediate
numbers that do represent halving and doubling the
amount of light
passed by the aperture. For
example, between f/2 and f/4 is f/2.8,
which is exactly twice as large as f/4 and half the size of f/2. The
actual
sequence of f-stops, each half the size of the previous aperture, is
f/2,
f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32 What’s going on here?
Everything
becomes clear when you realize that f-numbers are actually denominators
of
fractions that represent the size of the aperture opening, just as 1/2,
1/4, 1/8,
or 1/16 represent ever-smaller quantities. So, f/11 allows your
camera’s sensor
to collect more light than f/16 because 1/11 is a bigger number than
1/16. As
far as the camera is concerned, f-stops and shutter speeds are
equivalent. Cutting the shutter speed
in half produces the same effect on exposure as using an
f-stop that cuts the size of the lens opening in half. You get the same
image
if you take two pictures, one that has the exposure twice as long and
the other
by using an f-stop that’s twice as large. So, if your camera’s exposure
system
suggests an exposure of 1/500 of a second at f/8, you could reduce the
exposure
to 1/1,000 of a second (half as long) at f/8, or get the exact same
exposure at
1/500 of a second at f/11 (with the aperture half as wide). Strictly
speaking, your camera’s viewfinder isn’t part of the exposure process.
It does
have an important role, however, because the dSLR’s viewing system is
one of
the reasons (along with lens interchangeability) why people lust after
these
cameras in the first place. Non-SLR
digital cameras generally use an LCD on the back panel to provide a
real-time
image of what the sensor is seeing. This LCD view is often (but not
always)
coupled with an optical viewfinder window that you can also use to
frame the
image. That’s particularly handy under bright lighting conditions when
the
back-panel LCD is washed out. “Of
course, in a digital SLR, the sensor isn’t exposed to incoming light
all the time.
Instead, it sees photons for a brief interval, dubbed the exposure
time,
usually
measured in
fractions of a second. The exposure time can extend for many seconds in
the
case of a time
exposure. The
gatekeeper that controls these time slices, a sort of exposure-time
machine, is
the shutter.
The
shutter can be
a mechanical device (usually a curtain in front of the sensor that
opens and
closes very quickly) or an electronic mechanism that activates the
sensor for a
specific instant of time. Digital SLRs might have both, using a
mechanical
shutter for exposures measured in seconds from about 1/180
to
1/500
of
a second and an electronic shutter
for exposures in the 1/500
to
1/8,000
of
a second range. Longer
shutter speeds let in more light but can produce blurring if the
subject or
camera moves during the exposure. Shorter shutter speeds cut down the
amount of
light admitted, but they also reduce the chance that movement causes
blurriness.” In
short, the shutter speed (shutter priority is labelled Tv on the dial)
is the
length of time your camera sensor is exposed for. In dark environments
exposure
needs to be longer or supplemented with either more light ie: a flash,
a higher
ISO or a steady hand with
the aid of a tripod to avoid the capture of movement. ISO "In
photography, the sensitivity to light is measured by using a yardstick
called
ISO (International Organization for Standardization)." The Higher the ISO, the more sensitive your image is going to be to light. This allows you to have a higher f-stop or a quicker exposure/shutter speed to prevent blur in dark environments for a slight trade off in image quality. (higher ISO = more noise). NOISE "Visual
noise (or
just noise)
is that grainy look that digital photos sometimes get,
usually noticeable as multi-colored speckles most visible in the dark
or shadow
areas of an image. Although you can sometimes use noise as a creative
effect,
it generally destroys detail in your image and might limit how much you
can
enlarge a photo before the graininess becomes obtrusive. The
most common types of noise are produced at higher sensitivity settings.
Cameras
achieve the higher ISO numbers by amplifying the original electronic
signal,
and any background noise present in the signal is multiplied along with
the image information." HISTOGRAM “A
histogram
is
a graph that displays the tonal range of an image. You
can use a histogram to judge whether a photograph is or will be under-
or
overexposed. The trained eye can also see whether an image is likely to
have
excessive contrast or look particularly flat, based on the distribution
of
tones in a histogram.” A
typical histogram should look like a mountain, low on either end and
its peak
in the middle of it. In most cases this will be corrected in post editing software. COLOUR "Sometimes,
despite the best intentions and competent technique, you end up with pictures
that have bad color. Perhaps the picture has a green color cast caused by
fluorescent lights, or it has too much red because you took it late in the day.
Fortunately, image editors, such as Photoshop, let you fix these. You have a
lot of tools at your disposal. You can easily use some of these tools, but
others take a little practice. Before
you get started, keep in mind that you can’t add color that isn’t there in the
first place. If your image is way too red, you can’t compensate by adding its
opposite color (cyan). Image editors work by subtracting
hues. So, if your picture is dominated
by red and has very little green or blue, when you remove the excess red, you
don’t end up with a correctly balanced image. You wind up with a picture that’s
grayish because a little bit of red, blue, and green are all that’s left." SOFTWARE “If you’re really, really good at digital SLR photography, your
images might not need any fixing at all, right? Dream on. Nobody’s that good; even the most sharp-eyed shooter
still uses image editing, or what the cognoscenti refer to as post-processing. Image
editing is a skill anyone can master. One of the best things about digital
photography is that your images are digital all the way. You don’t need to scan
film or a print or do any conversion. What you shot is what you got — a digital
image full of pixels just waiting to be tweaked, fine-tuned, shifted around,
and optimized. You can do a lot of that in your camera, but for even greater
image enhancement, you need an editor, such as Adobe Photoshop, Paint Shop Pro
or a free alternative like GIMP You can manipulate your photos in two different ways: by fixing
anything that you see as a defect without really changing the content
extensively, or by combining and reorganizing images in more drastic ways. I
show you the basics of combining and reorganizing (which includes compositing, or melding several different images or parts of
images) in Chapter 12. In the following sections, I stick with the techniques
for making repairs and fixes. The most common fixes for digital photos fall into five
categories: · Cropping:
As you can discover in
Chapter 10, you can often improve a photo just by removing items that don’t
belong or that distract from the composition. Cropping — adjusting the borders of
an image — is the easiest way to remove things from a photo. · Tonal
adjustments: Your images might be too
bright or too dark, or worse, include some parts that are too dark and others
that are too light. Although your dSLR includes features that let you make some
adjustments for tone (including specialized tonal settings called custom curves), frequently you can more easily make these
adjustments by using an image editor. · Color
correction: If your colors are off,
you can usually fix them in your image editor. If your colors are accurate, you
might want to make them seem off as a creative effect. You can do
both with your editor. · Spot
removal: Your dSLR shots might have
a variety of different spots and artifacts that you need to remove. A dirty
sensor can produce dust spots on pristine images. Perhaps birds in the sky off
in the distance are too small to look like anything other than blotches. Your
subject might have a small scratch or defect. You need an image editor to touch
up these spots. · Sharpening/blurring:
You can change the
emphasis within your composition by selectively sharpening or blurring parts of
the picture. You can also salvage a shot that isn’t quite sharp enough by using
a little sharpening or smooth out rough texture by using blurring.” Digital SLR Cameras & Photography For Dummies®, 3rd Edition Copyright © 2009 by Wiley Publishing, Inc., Indianapolis, Indiana Published by Wiley Publishing, Inc. |
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