Camera Basics
Digital Cameras are really little computers with
a Lens attached and a Sensor inside. The only reason I point this
out is because it's important to take care of your digital camera
the same way you would any other piece of sensitive electronic
equipment that you want to be serviceable for a number of years.
All cameras have a Body, a Lens, a Preview Screen
and/or Viewfinder, Shutter Release, and Control options. Nearly
all the digital cameras that I know of also have a built in flash.
The control options may be accessed by either
Buttons, a Dial, and/or a Menu, which is viewable via the Preview
Screen.
Instead of Film, digital cameras have a Sensor
built in. The Sensor acts very similarly to Film in that it is
sensitive to light, and it records the light that reaches it through
the lens. Unlike film, the sensor then sends the recorded light
to a Storage Device, such as a Compact Flash Card, or Memory Stick.
Also unlike film, the sensor makes its recording in computer language…in
other words as ones and zeros, rather than light activated dyes.
DSLR Cameras
DSLR stands for Digital Single Lens Reflex. These
are more advanced and have more features than the smaller Consumer
variety, and are usually referred to as "Pro-Sumer", or Professional
cameras.
SLR means that when you look through the Viewfinder,
you are actually looking through the Lens via a mirror and prism
setup. Generally DSLR cameras give you the option to change the
lens, giving you a greater range of creative options. Also, DSLR
cameras of the Prosumer and Professional variety have a much faster
response to the Shutter Release Button. And are considerably more
expensive. Consumer digital cameras generally do not have a Viewfinder,
but rely on the Preview Screen, and have a very noticeable lag
between depressing the Shutter Release, and the making of an exposure.
Pixels, Megapixels, and Image Quality
A Pixel is a tiny dot containing information.
A Megapixel is One Million Pixels. That sounds like a lot, but
Pixels are really small, and most better quality prints require
240 Dots per inch or more. That doesn't sound like so much until
you realize that really means 240x240…which equals 57,600. An
8x10 print requires about 4.6 million dots or pixels. With a 6
Megapixel Sensor, a very nice print up to about 11x14 inches may
be made without much trouble. With a 10 Megapixel Sensor, a print
of up to about 16x20 inches may be made without much trouble.
If you have advanced software such as the Pro
version of Photoshop, or Fractals, you can get a whole lot more
out of your camera's Pixels! I personally have made beautiful
portrait prints as large as 40x60 inches using an original image
made with a 6.2 Megapixel capture!
Exposure Basics
(Photo = Light, graph = record), When we
make a Photograph we are actually making a recording of light.
The light reflected by the subject of our photograph. To do this
we Expose the Sensor in the camera. There are 3 ways to control
the exposure. One way is to control the Length of time of exposure
by setting the Shutter Speed. Another is to control the size of
the Aperture in the Lens, known as an F stop. The size of the
aperture determines how much light is let into the sensor at once.
The last is to control the sensitivity of the sensor by adjusting
the ISO rating. (ISO stands for International Standards Organization).
This is interchangeable with ASA, or American Standards Association.
If yours is a "Point and Shoot" consumer digital
camera, this part of the presentation will be useless to you…unless
you plan to upgrade in the future…Because, in your case all these
adjustments are made by the computer with a lens!
If your camera has a choice of Program Modes,
you can at least influence how the camera makes the adjustments.
If yours is a Basic digital point and shoot, probably the only
influence on exposure you can make is to tell the camera that
the scene is "Back lit", or if you are indoors, or outdoors on
a bright or cloudy day. Sorry for you! The next sections will
be of more help.
Proper exposure is determined by a combination
of the 3 controls I mentioned: ISO, Shutter Speed and F stop.
Once the proper exposure is set, if you change any one of those
3 parameters, you must also change at least one of the others!
For example, if your correct exposure is F8 at 1/125th of a second
and 200 ISO, if you change the ISO without changing either the
Shutter Speed or Fstop, or both, you will either OVERexpose or
UNDERexpose the photograph. The same is true if you change the
Shutter Speed or the F stop without a corresponding adjustment
of the other parameters.
Here's why: The Shutter Speed controls How Long
the sensor is exposed to the light. The F stop controls the Volume
of light getting to the Sensor, and the ISO determines How Much
Total light is required to expose the sensor in any given situation.
Think of it this way: If you have a Bucket and
you want to fill it with water from a hose. Let's say your bucket
holds a gallon, and let's say your hose is 1" in diameter. If
you turn the water on for say 30 seconds full blast, that fills
the bucket right to the top perfectly.
Think of the Bucket as the ISO rating, the hose
as the F stop or Aperture, and of course the time the water is
turned on as the Shutter Speed.
If you use a 2 gallon bucket and want to fill
it with the same 1" hose, and you turn the water off in 30 seconds,
your bucket is only going to be half full! Or half exposed! So
you would need to send the water for a full minute with the 1"
hose to fill the larger bucket. Now, if you were to use a 2" hose
for 30 seconds, that would fill the 2 gallon bucket up perfectly!
If you were to use the 2" hose to fill the ONE gallon bucket,
it would be overflowing for a full 15 seconds.
The point is, with the light being the same, any
time you change one of those 3 parameters, you must adjust one
or both of the others in order to maintain the correct exposure.
Light and Shadow
See the Light! This I consider to be the
1st Rule of Photography as all else follows. 'If the Light ain't
Right, the Photograph will BITE!' No light, No photograph!
So, the questions are: Where Is The Light Source?
Where Do The Shadows Fall (that are created by the light source)?
Also: Where Am I in relation to the light source?
And: How Can This View Be Improved? (or can it not be improved,
by you, under the circumstances)
These questions relate to everything about creating
a photograph. The human eye can see detail in bright areas and
in dark areas at the same time much better than digital sensors!
And even much better than film. So it becomes very important to
be aware of where the shadows are, and how relatively dark they
are. What may look fine to your eye as far as contrast in a scene,
or especially when people are the subject of the photograph, often
will not translate anywhere close to the same in a photograph.
Where a contrast of 1000:1 may be great when it
comes to your LCD TV, if it exceeds 4 to 1 in a photograph, the
shadows are starting to get pretty dark, and by about 7 to 1 in
contrast, there's no detail in the shadows at all.
One aspect where this is good to know is when
your subject is mostly in shadow but has a significant area in
direct sunlight, there's a good chance you're going to loose all
the detail in the shadow area.
If you can move your subject, or get yourself
into a different position so the shadow doesn't cover so much
of your view, then even when you loose detail in the shadows,
it doesn't take away from the image. In fact it can improve it.
If the subject is a person, you can move them, or have them move
so the light and shadow on them is more complimentary. If the
subject is a mountain, you either need to reposition yourself,
or accept that you will loose detail in either the shadows or
the highlights, and the image will loose impact.
In people photographs, you want to avoid sun directly
in the eyes! Ideally, you can have the subject move so the sun
is at nearly a right angle to their face, but enough in front
of them so that both sides of the face get light. Or if there's
an area where there is a large area of shade that isn't very dark,
or what is referred to as "open shade", that can be ideal for
making people photographs as well. Just remember that if you're
in an open shade area and in the background there's a section
of bright sky, you'll loose the blue in the sky and the clouds
if there are any. Why? Because if you are making a good exposure
for your subject who is in the open shade, the sky in the background
will be way over exposed and turn out all white with no detail.
Generally speaking, if what you are photographing
is 3 dimensional and has texture, full front lighting, or what
is termed "Flat" lighting is not the most complimentary or impactful.
Flat lighting eliminates shadows pretty much all together, so
while it may provide nice even light, the subject then looses
dimensionality.
Since photographs are basically 2 dimensional,
you will create a more pleasing image if your light has "Directionality".
If the light source is above, to the side, somewhat in front of
the subject, the shadows created will define the features or texture.
How much so depends on the angle of the light to the subject.
This is something you can easily experiment with.
The main point here that I want to impart is that
you need to see the light and the shadows. Look for the shadows.
See where they are and how dark they are compared with the brightest
part of whatever it is that you want to photograph. And realize
that if you have an area of dark shadow in the scene, you will
most likely loose all detail in the shadow area.
There are ways to control where you loose detail,
or to compromise. If your camera has a built in light meter, and
a zoom lens, you can zoom into the shadow area and read the exposure,
then zoom into the highlight area and read the exposure for that,
then set the exposure in the middle of the two. This would be
a compromise where the shadows will be a little Under, and the
highlights a little Over exposed. As a general rule, in Digital
photography you can bring back more detail in under exposed areas
than you can in Over exposed areas with photo software. So it
is advised that when you don't have better options, expose for
the highlights.
Now, most cameras built in light meters are activated
by depressing the shutter release button Half Way. When you do
that and you are looking through the viewfinder, you will see
a zero mark at the bottom middle of the viewfinder with vertical
hash marks on either side. When the scene or area you are metering
is Underexposed the hash marks will be to the right of the zero
mark. When it's Overexposed the hash marks will be on the left.
When the exposure is just right, only the zero mark will be visible.
That is to say, when the computer thinks the exposure
is just right. But you need to keep in mind that the computer
is reading the entire area that is in the viewfinder. That's why
you want to zoom in to the most important part of the scene to
set your exposure. You may end up sacrificing detail in another
area of the photograph, but at least the most important part will
be properly exposed. And that is why so many photographs where
the subject is people, and they are standing in front of a beautiful
sunset, and the sunset comes out pretty well, but the people are
mostly silhouette! So this is where you turn the flash on when
shooting into the sun!
There are just a couple more things I want to
share with you about exposure adjustments. The shutter speed,
if fast enough will stop motion, but if it's slow enough it will
make for a very blurred photograph! Note the length of the lens
you are using. If it's a zoom lens and goes from 24 to 135, (that's
the Focal Length in millimeters, BTW), set the shutter speed to
1/150th or faster to prevent blur. So, the rule of thumb is to
set the shutter speed at or faster than the focal length of the
lens. If what you are photographing is in motion, a general rule
of thumb is to set the shutter speed at 1/500th or faster! Obviously
you will need to adjust the ISO and or F stop at the faster speeds
to get a good exposure.
Now with F stops there is another function besides
the volume of light it lets in. This additional function is called
"Depth of Focus", or "Depth of Field". This simply refers to how
far the focus extends from the point of focus. The distance the
lens is from the subject also plays into this, but for our point
of discussion here, let's say you are 10' from your subject, and
the correct exposure is F 11 and 1/250th of a second at ISO 200.
Let's say your subject is people, and the background, while fairly
distant is also quite busy and distracting. What do you do? Well,
you can cause the background to go well out of focus if you can
get a good exposure with the aperture open to F 5.6 or larger,
(F4, F3.5, F2.8, F1.4, F1). This is because the wider the aperture,
the shorter the Depth of Focus, and the smaller the aperture,
the longer the Depth of Focus.
What you need to remember about F stops is that,
(and this is a little confusing for most people at first), the
Higher the Number, F11, 16, 22, 32, 64, the SMALLER the aperture.
So the Lower the Number, F8, 5.6, etc, the WIDER the aperture.
You also want to remember that the higher the
number of the F stop, not only does it let less light in, but
it Lengthens the depth of focus, so that more is in focus behind
the point of focus, (your subject). Conversely, the smaller number
lets more light in, and also shortens the depth of focus.
In our example where the correct exposure is F
11, 1/250th at ISO 200, if you open the lens to F 5.6, that's
2 F stops. In order to maintain a correct exposure you must change
the shutter speed by a corresponding 2 stops. In shutter speed
that will be from 1/125th to 1/1000th. Because every full F stop
equals either twice or half the shutter speed. F 5.6 allows twice
the light as F 8, which allows twice the light of F 11. So, 1/1000th
allows half the light as 1/500th, and that's half the light as
1/250th.
If you can drop the ISO to 100, that will be
half the exposure as ISO 200. So another way to correct the exposure
in this example would be to drop the ISO to 100, and the then
the shutter speed will only need to go to 1/500th.
Composition
This is perhaps the most 'artistic' aspect of
making photographs, while exposure is more science. Of course
exposure may also be used in conveying an artistic message, but
it still requires knowledge of the science of exposure in order
to 'use' it artistically. And since art is in the eye of the beholder,
or creator of the photograph, it's a very individual and personal
thing, so that's it for my presentation!
Na na na…jus kidding!
In art school we are taught about the rule of
thirds, converging lines and positive and negative space along
with color harmony, balance and other "rules". These are the kinds
of rules that are made to be broken. They are more guidelines
of what is generally considered to be aesthetically pleasing.
When photographing a landscape, it's usually best
to make sure the horizon is level. Other than that, frame or compose
the image the way it looks good to you!
Some tips to making more striking landscapes are;
Be aware of what the most interesting part of the scene is, and
try to compose the photograph so that it is visually highlighted.
That can be effected because all or most of the lines in the scene
defined by objects such as mountains, the horizon, a path or road,
line of trees etc lead the eye of the observer to the most interesting
area. Or it can be because there is a beam of sunlight falling
on the interesting area while the rest of the scene is in relative
shadow.
Generally you want the eye of the observer to
travel around within the image, rather than to move from the image,
out of the image. You can accomplish this by composing the image
so that the lines direct the eye from one point to another within
the image. Another way is to utilize Negative Space. Negative
space is dark while positive space is light. Dark colors recede
while light colors come to the fore. So one way to hold the viewer's
attention using negative space is to compose your image so that
the foreground is relatively dark and the main subject is relatively
light. And while the subject is more in the background, because
it is lighter than the foreground, it will capture the focus of
the viewer. You can also reverse that scheme and get a similar
result.
When there are people in the landscape, whether
they are the main subject or not, they add interest…at least to
people…So, what the people are doing and where they are placed
in the image can have a lot of impact. If the person or people
are standing observing the scene, let's say, if they are placed
at one side of the image and are looking into the image, this
makes it comfortable for the viewer of the image and keeps their
interest within the scene. If the person or people are placed
to the side of the image and are looking away from the rest of
the scene, it becomes a little uncomfortable to the viewer because
the person's gaze leads OUT of the scene, and the viewer will
also want to look out of the image.
When you are making a photograph of a person or
group of people, generally you want to keep the people the focal
point. You can place the subject off center as long as the background
has some interest but doesn't distract from the subject. Most
of the time however, you want less background and more subject,
so centering the subject and coming in rather close so they mostly
fill the frame is recommended. And usually you will want the background
to be much less In Focus so it doesn't compete for attention with
the subject. So, use a larger Aperture, and get the camera relatively
close to your subject.
Some other tips for photographing people…A more
pleasing camera angle is usually at eye level with the subject,
or slightly above eye level. In people photography, the eyes are
really the focal point of the image, so you want to actually focus
your camera on the EYEs of the subject.
When photographing little children, get down to
their level, so you're eye level with them. My personal advise
when working with small children is to give them something to
do that will keep them occupied. Then just let them be themselves,
and capture images of them having fun!
When you're photographing a group of people, especially
when there are people behind others as in rows of people, you'll
want a smaller aperture so your depth of focus doesn't run short
of the people in the back!
