A Beginner's Guide to Simple Photography Concepts: ISO, Aperture, and Shutter Speed

There’s a device in the camera called the diaphragm, which is directly connected to aperture. The different aperture settings are called f-stops, and are represented by the numbers you see on the image. The larger the number, the smaller the aperture, so for example, an f-stop of f1.4 would be very large, while an f-stop of f16 would be very small. Typically, most consumer lenses have a range of f2 to f16. Don’t be overwhelmed by the technical terms and numbers and things like that, once you try everything out on the actual camera, it will all start to make sense. When I first went over the module on this it was all gibberish to me, until I actually took some pictures trying all the different settings. That’s when it all made perfect sense.

Now, usually a faster shutter speed will require a larger aperture to allow enough light into the camera, and a slower shutter speed will need a smaller aperture to prevent too much light from getting in. You see, shutter speed is how long the shutter is open to allow light into the camera. Shutter speed is always measured in seconds. To demonstrate the effect of ISO, see the below image. Each photo was taken at 1/250th of a second, and the aperture set to f5.6, while the ISO was changed. The ISO is simply how sensitive the film, or censor in a digital camera, is to light. The lower the ISO is, the less sensitive it is to light. The higher the ISO is, the more sensitive it is to light. You can see from the photo, that at 100 ISO, the picture is quite dark. At 400 ISO, the picture is better, and at 1600 ISO, the picture is far too bright. Depending on the ISO you are using, your shutter speed will have to be adjusted to allow the right amount of light for what you want to achieve.

The more light that is available, the faster your shutter speed can be. The type of light will also change things, but that gets more complicated. All light has a temperature in degrees Kelvin, which also affects things. I won’t get into that yet, as it’s a little more advanced.

Now, let’s talk a little about why shutter speed is important. It’s pretty simple, actually. The faster your shutter opens and closes, the less you have to worry about a blurry image. For most people, a shutter speed of 1/60th of a second is the slowest you can hand hold the camera before experiencing blur due to camera shake. If you are photographing a still object, or a slow moving object, a fast shutter speed isn’t as important. If you are photographing a fast moving object, a fast shutter speed suddenly becomes a necessity most of the time. Now remember, the higher the ISO, the more sensitive the film/censor will be to the light. So one might think it’s best to always use the highest ISO possible, right? The correct answer is; sometimes. In the next image we see something new, called grain.

Grain is essentially how nice your photos look. Most of the time, you won’t be able to tell the difference in grain at standard print size of 4x6. However, if you ever have a photograph you’d like to enlarge, ISO suddenly becomes very important. The higher the ISO, the grainier your photo will look. Below I cropped just the face of an image, one at 100 ISO and the other at 1600 ISO. The first photo looks smoother, while the second looks, well, grainy. Most consumers won’t need to be making a lot of enlargements, so this doesn’t always matter. But even an amateur will sometimes get that one perfect shot they just would love to hang on their wall. Unfortunately, if that perfect shot was taken with a high ISO film, or using a high ISO setting on a digital camera, the size of the enlargement will be limited before it starts to look bad. I find for the average every-day John and Jane Q. Normal, 400 ISO is best. It gets more complicated of course if you’re looking at it from a professional level, and I may get into that another time.

Finally, we get to what most people get lost on, Depth of Field. Let’s start this time by looking at a picture.

Most likely, in the first frame, your eye is attracted to the figurine. This is because the back round is blurred, and unobtrusive. In the second frame still focused on the figurine, but a little distracted. In the last frame, your eye was probably drawn first to the red box, and when you look at the figurine, you’re distracted by the box in the center. So as you can see from the pictures, depth of field is essentially the area in front and behind the object that is in focus..

Each photo was taken with the same ISO, but both the shutter speed and aperture were changed. As you can see, the back round became less blurred the smaller the aperture. The entire time I kept focused on the figurine. Anything in front of, or behind the figurine would appear blurry. You can set things up however so that your depth of field is infinite (to a degree) and everything is sharp. The further away something is, the more infinite the focus can be. The closer it is, the more limited that becomes. For example, if taking a macro photo of a small insect, you can have the insect in focus, but no matter what lens or camera you have, you can focus on both the insect up close and mountains in the distance. The closer something is, the more limited the depth of field will be.

Depth of Field is probably the most confusing to beginners, because reading about it can be complicated, as there are many different factors that will affect your depth of field. For example, a telephoto lens will have a more sensitive depth of field, while a wide angle lens will be less obvious. It’s easiest to tackle this one factor by taking your camera out and just trying the different aperture settings and distances from objects. Some cameras will have a depth of field preview button, that will show you in the viewfinder how the depth of field will look. This is a very helpful function to have, but if not, trial and error must be used for the beginner.

The best thing to do is buy or rent an old, fully manual film camera. The biggest problem most beginners face is the ease of automatic features. Buying a fully manual camera forces you to learn these beginner concepts, which will aid greatly in how all you photographs will look in the future. My 2 favorite manual cameras are the Pentax K1000 and the Canon AE-1 (But do not get the Canon AE-1 Program, as it is largely automatic if you want it to be).

The settings for all these functions will be available on most digital cameras, not just SLR’s. Chances are if your camera is 3 megapixels and up, it will have the right functions. You’ll have to consult your manual for help on where to find them and how to set them on your camera however.

Next time, I will talk about the basics of composition, exploring things like image placement, shapes and perspective.

by: redsunphotography
Source: http://www.dpchallenge.com/

ISO or ASA in Photography - Sensitivities in Camera Sensors

ISO (I.S.O.) is the abbreviation for the International Organization of Standardization, a governing body based in Europe that provides the standards for a wide variety of subjects.

For photographers the key standard is Film Speed ratings. In the past this was known as ASA or the American Standards Association (Now discontinued and replaced by the American National Standards Institute or ANSI), and you could buy your films in ASA 50, 100, 200, 400, 800 and 1600. There were specialist films that would go higher or use infra-red although these were generally known as the standard speeds.

Most decent cameras now have interchangeable ISO settings which is especially useful for digital photography because, as discussed in the previous chapter, you can change the ISO setting for every shot you take without the need to change film.

So what ARE the settings and how do they affect your photos?

The standard I.S.O that most people use everyday, giving accurate colour rendition and "clean" noise-free images is 100 I.S.O.

If your camera is able to set a lower ISO of 50 or less, you will notice that the images become a little more saturated in their colours. You won't see too much difference in quality like you do with 50 I.S.O. Slide film, but a slow film speed or I.S.O. with digital photography has its benefits nonetheless.

50 I.S.O or less

There have been occasions when I have come across a particularly bright scene such as a sunny, white sandy beach or a sun kissed bleach-white property on a sunny day where I simply have too much light all around me.

I am already on the fastest shutter speed that the camera will allow and the smallest aperture that I wish to use (N.B. I never try to go smaller than F16 or F22 otherwise the image quality can start to deteriorate, or I may wish to create some depth of field with an aperture of say F5.6). By reducing the I.S.O. to the lowest, I can maybe save a few shots whilst enhancing the colours.

Also when shooting images that I want to be rich in colour such as a beach scene with blue skies and deep blue water for a holiday magazine, I use the lowest ISO possible (normally 50) coupled with a polarizer filter.

You may also want to purposely slow down the shutter speed for some creative shots. If you read enough photography magazines you will have undoubtedly seen images of waterfalls with milky smooth water and pin sharp rocks and foliage?

The milky water is created by a very slow shutter speed (normally a matter of seconds), which can sometimes only be achieved with the help of the smallest aperture and lowest ISO setting.

The small aperture and low ISO block most of the light which means you need to compensate with a long shutter speed which in effect causes the flowing water to "blur" itself onto the sensor. Obviously when doing this kind of shot a tripod is essential.

Standard I.S.O - 100

As I mentioned earlier, this is the industry standard for most situations and subjects. Whether you shoot weddings, portraits, studio or commercial, 100 I.S.O. will do just fine and create nice, clean colourful images across the board.

High I.S.O - 400 and above

Being quite a perfectionist myself, as I think most photographers are, I like to produce the cleanest and noise free images as possible. I also like bold, colourful images.

Unfortunately, there are some times when you just have to use higher I.S.O.'s in order to get the shots you need:

• Weddings - For many interior shots of the church and ceremony, I don't like to use flash as it causes unnecessary distractions from the service. Even with the aperture wide open you will struggle to get a fast enough shutter speed to freeze any movements especially when hand-held at ISO 100 or 200. Even using a tripod doesn't help if you have a slow shutter speed and the subject is moving, even the slightest amount. I have used ISO's as high as 800 and 1600 for the darkest of churches and have ended up with some great shots which, after using Neat Image, are quite acceptable and clean.
  

  

  With the more modern and technological digital SLR's (especially in the Canon and Nikon camp, Canon EOS 1Ds MKIII, EOS 5D and the Nikon D3), the sensor arrays are becoming that much better with larger pixels, the quality at high I.S.O.'s is quite superb.
  
• 
  Indoor sports - For events such as show-jumping or similar, where the subject can be too far away for effective flash use and the light is too dim for hand held photography at low I.S.O.'s, you need to obtain as fast a shutter speed as possible to freeze the action. When you are at the widest aperture, your only other option is to whack up the ISO to 800 or 1600. Get to a point where you have a shutter speed of 250th/sec or faster and "pan" with the action as much as possible.
  

Quality

The biggest problem when using high ISO's is the quality deterioration. If you have ever used high I.S.O. film such as 800, the emulsion used on the film contained larger, more sensitive "grains" which were perfectly visible in your images thereby reducing quality.

Now, with digital cameras, the higher ISO's produce digital "noise" which is similar in appearance to grain and caused by increasing the pixel's sensitivity. As I mentioned before, there are more and more programs becoming available which help to reduce this noise to an acceptable level such as Neat Image or Noise Ninja.

Noise or grain can also be your friend if you intend to get creative at some point. Many black and white images can have their mood greatly enhanced by adding grain or noise to them and most editing software even has the facility to add noise. So learn to control noise and either remove it or increase it depending on what effect you need.

The main thing to remember is that your camera has 3 main controls for adjusting the amount of light in your images:

• Shutter Speed
• Aperture
• I.S.O
  

Once you learn these in their entirety, what they do and the effects they achieve and when to use each one effectively, then you need to concentrate on your composition and subject matter!

Source: http://www.all-things-photography.com/

What is Exposure?

The Basic Elements of Exposure
Exposure, in photographic terms, is the process of capturing light with your camera to produce an image on film or a digital sensor. (Film and digital sensors will be referred to as film throughout this document unless specifically noted otherwise.) Your camera mechanically controls the incoming light and directs it to the film. The film is sensitive to the light and is exposed.

We can create a simple analogy of exposure in terms of filling a bucket with water. We can fill the bucket slowly with a small stream of water, or we can fill it quickly with a large stream. In either situation, it will take a combination of time and water flow to fill the bucket. The size of the bucket is also a consideration. A small bucket will fill more quickly than a large one.

Based on this brief analogy, we have three items to consider. We have water flow, the amount of time it takes to fill the bucket, and the size of the bucket. We can approach our Fill the Bucket project from several angles. We can choose to use a larger or smaller hose. We can choose to fill the bucket quickly or slowly. We can choose the size of the bucket we want to fill. Whichever approach or combination of approaches we choose, the result will be the same. We will put water in our bucket. We may fill it completely full, partially full, or let it overflow.

How do we relate this analogy to our camera?
Light is the water that flows through our hose.

Our camera's aperture is the hose. The camera's aperture is the device that controls the amount of light that is allowed into the lens. This aperture is adjustable. We can make it larger or smaller.

Our camera's shutter speed is the amount of time it takes to fill the bucket with water. The camera's shutter is the device that opens to allow the incoming light from the aperture to expose the film and create the image. The film's sensitivity or ISO number is the size of the bucket. Small buckets (more sensitive films) can be filled faster than large buckets (less sensitive films.)

The Four Elements
So, we have four elements of exposure: light, aperture, shutter speed, and film sensitivity. Each of these elements plays a distinct role in the process of creating a photograph. Each of these elements may be used in creative ways.

Light
Light is probably the most important element of exposure. In many cases, good and bad photos are only differentiated by the available light in the scene. Learning the difference between good and bad light is part of the overall experience of learning about photography. Light creates shadows, highlights textures, accents colors, creates moods and emotions, and a vast array of other enhancing effects in a photo. By the same token, light can also create harsh contrasts, bright spots, dark spots, glare, and other issues that are sometimes associated with poor photographs. Finding the good light is a skill that comes with experience and a lot of trial and error.

Aperture
Your camera's aperture controls the amount of light that is allowed into the lens. The aperture is an adjustable hole inside your lens that may be made larger or smaller to control the intensity of the available light. The aperture is also used to control depth of field. Depth of field will be discussed in detail as we explore exposure a little deeper.

Shutter Speed
The camera's shutter is the device that opens and closes for a specified amount of time to allow the light entering the lens to expose the film. The duration of the opening is determined by the amount of light entering the lens. The aperture and shutter work together to produce correct exposures.

Film Sensitivity (ISO)
Some films are more sensitive to light than others. The ISO rating of the film describes its sensitivity to light in numbers such as 25, 50, 100, 200, 400, and 800. 200 speed film is twice as sensitive to light as 100 speed and four times more sensitive than 50 speed film. 200 speed film will expose twice as fast as 100 and four times faster than 50. Different speeds of film are used for various reasons that we will discuss soon. These four elements of exposure work together to produce a photograph. Light enters the camera through the aperture inside the lens. The shutter opens and then the film is exposed. In our quest to understand exposure, we must learn how each of these elements interacts with each other. We also must learn how to control each element to produce our desired result.

by : JMSetzler
Source: http://www.photos-of-the-year.com/

10 Top Photography Composition Rules

There are no fixed rules in photography, but there are guidelines which can often help you to enhance the impact of your photos.

It may sound clichéd, but the only rule in photography is that there are no rules. However, there are are number of established composition guidelines which can be applied in almost any situation, to enhance the impact of a scene.

These guidelines will help you take more compelling photographs, lending them a natural balance, drawing attention to the important parts of the scene, or leading the viewer's eye through the image.

Once you are familiar with these composition tips, you'll be surprised at just how universal most of them are. You'll spot them everywhere, and you'll find it easy to see why some photos "work" while others feel like simple snapshots.

Rule of Thirds

Imagine that your image is divided into nine equal segments by two vertical and two horizontal lines. Try to position the most important elements in your scene along these lines, or at the points where they intersect. Doing so will add balance and interest to your photo. Some cameras even offer an option to superimpose a rule of thirds grid over the LCD screen, making it even easier to use.

Notice how the building and horizon are aligned along rule-of-thirds lines. Image by Trey Ratcliff.

Balancing Elements

Placing your main subject off-centre, as with the rule of thirds, creates a more interesting photo, but it can leave a void in the scene which can make it feel empty. You should balance the 'weight' of your subject by including another object of lesser importance to fill the space.

Here, the visual 'weight' of the road sign is balanced by the building on the other side of the shot. Image by Shannon Kokoska.

Leading Lines

When we look at a photo our eye is naturally drawn along lines. By thinking about how you place lines in your composition, you can affect the way we view the image, pulling us into the picture, towards the subject, or on a journey 'through' the scene. There are many different types of line - straight, diagonal, curvy, zigzag, radial etc - and each can be used to enhance our photo's composition.

The road in this photo draws your eye through the scene. Image by Pierre Metivier.

Symmetry and Patterns

We are surrounded by symmetry and patterns, both natural and man-made., They can make for very eye-catching compositions, particularly in situations where they are not expected. Another great way to use them is to break the symmetry or pattern in some way, introducing tension and a focal point to the scene.

The symmetry of this chapel is broken by the bucket in the bottom right corner. Image by Fabio Montalto.

Viewpoint

Before photographing your subject, take time to think about where you will shoot it from. Our viewpoint has a massive impact on the composition of our photo, and as a result it can greatly affect the message that the shot conveys. Rather than just shooting from eye level, consider photographing from high above, down at ground level, from the side, from the back, from a long way away, from very close up, and so on.

The unusual viewpoint chosen here creates an intriguing and slightly abstract photo. Image by ronsho.

Background

How many times have you taken what you thought would be a great shot, only to find that the final image lacks impact because the subject blends into a busy background? The human eye is excellent at distinguishing between different elements in a scene, whereas a camera has a tendency to flatten the foreground and background, and this can often ruin an otherwise great photo. Thankfully this problem is usually easy to overcome at the time of shooting - look around for a plain and unobtrusive background and compose your shot so that it doesn't distract or detract from the subject.

The plain background in this composition ensures nothing distracts from the subject. Image by Philipp Naderer.

Depth

Because photography is a two-dimensional medium, we have to choose our composition carefully to conveys the sense of depth that was present in the actual scene. You can create depth in a photo by including objects in the foreground, middle ground and background. Another useful composition technique is overlapping, where you deliberately partially obscure one object with another. The human eye naturally recognises these layers and mentally separates them out, creating an image with more depth.

Emphasise your scene's depth by including interesting subjects at varying distances from the camera. Image by Jule Berlin.

Framing

The world is full of objects which make perfect natural frames, such as trees, archways and holes. By placing these around the edge of the composition you help to isolate the main subject from the outside world. The result is a more focused image which draws your eye naturally to the main point of interest.

Here, the surrounding hills form a natural frame, and the piece of wood provides a focal point. Image by Sally Crossthwaite.

Cropping

Often a photo will lack impact because the main subject is so small it becomes lost among the clutter of its surroundings. By cropping tight around the subject you eliminate the background 'noise', ensuring the subject gets the viewer's undivided attention.

Cut out all unnecessary details to keep keep the viewer's attention focused on the subject. Image by Hien Nguyen.

Experimentation

With the dawn of the digital age in photography we no longer have to worry about film processing costs or running out of shots. As a result, experimenting with our photos' composition has become a real possibility; we can fire off tons of shots and delete the unwanted ones later at absolutely no extra cost. Take advantage of this fact and experiment with your composition - you never know whether an idea will work until you try it.

Digital photography allows us to experiment with different compositions until we find the perfect one. Image by Jule Berlin.

Composition in photography is far from a science, and as a result all of the 'rules' above should be taken with a pinch of salt. If they don't work in your scene, ignore them; if you find a great composition that contradicts them, then go ahead and shoot it anyway. But they can often prove to be spot on, and are worth at least considering whenever you are out and about with your camera.

Source : www.photographymad.com

What Is... Aperture?

When you look at the technical specifications of a digital camera, one of the
very first specification mentioned is its maximum aperture and/or its
aperture range.

What is 'aperture,' what is a good aperture range, and how is aperture relevant
when it comes to choosing a digital camera?

What Is Aperture?

The main function of a camera lens is to collect light. The aperture of a lens
is the diameter of the lens opening and is usually controlled by an iris. The
larger the diameter of the aperture, the more light reaches the film / image
sensor.

Aperture is expressed as F-stop, e.g. F2.8 or f/2.8. The smaller the
F-stop number (or f/value), the larger the lens opening (aperture).

[Note: Many camera user manuals today will refer to the aperture in terms of
"aperture value" instead of f/value. I'm not sure when this trend
started but don't get confused between "aperture" and "aperture
value." Aperture value" is simply another way of saying f/value.]

In practice, unless you are dealing with a fixed-aperture lens (many simple
point-and-shoot cameras have only one fixed aperture), the aperture of a lens
is usually expressed as a range of fstops.

When you read the specifications of a camera, the aperture may be expressed
in a number of different ways, the following three being the most common:

• Maximum Aperture:

Max. Aperture

F2.8

This simply states that the maximum aperture for the lens is F2.8.

• Aperture Range:

Aperture Range

F2.8-F8.0

This states the max. and min. aperture, the assumption being that there are
standard increments between them.

• Maximum Wide-Angle and Telephoto Apertures:

Aperture

F2.8-3.5 or F2.8(W)-F3.5(T)

This gives the max. aperture for the wide-angle (F2.8) and telephoto (F3.5)
focal lengths of a zoom lens.

It is usually not too difficult to figure out that a stated range deals with
maximum apertures and not max and min apertures: the mimimum aperture should
be quite small at F8, F11, F16 or F22.

A "fast" lens is one that has a large maximum
aperture (F2.4, F2.0 for current digital cameras; F1.4, F1.2 for 35mm film cameras).

Quick Quiz: which lens has a larger opening (aperture): one with an aperture
of F1.8 or one with an aperture of F2.8?




Answer: F1.8 (remember,
the smaller the F-stop, the larger the aperture)

A Good Aperture Range

My personal preference for a 'good' aperture range is:

F1.8 - F16

F1.8

F2.8

F4

F5.6

F8

F11

F16

This tells us that the camera has an aperture range of F1.8 to F16;
the maximum aperture is F1.8, and the minimum aperture is F16.

There are 5 f-stops between the max and min aperture. If your camera's lens
is currently set at an aperture of F5.6, closing it by 1 f-stop would mean selecting
F8; opening it up by 1 f-stop would mean selecting F4.

F1.8

F2.8

F4

F5.6

F8

F11

F16

How Is A Large Maximum Aperture Relevant?

A large maximum aperture is preferable to a smaller one since it gives
the photographer more latitude in the kind of pictures that can be taken.

For example, it is pretty obvious that the larger the aperture, the better
your digital camera will perform in low-light situations, since a larger
lens opening is able to admit more light than a smaller lens opening.

A larger max. aperture also allows you to use a faster shutter speed
to freeze action.

So, let's say the light meter in your digital camera calculates that for proper
exposure in that indoor arena, you need an aperture of F4 and a shutter speed
of 1/60 sec.

F4

1/60

To use a faster shutter speed (say, 1/250 sec.) to freeze action, you have
to open up the aperture to allow more light in for that shorter amount of time.

For every shutter speed increment we go up, we need to open up a f-stop of
aperture. From 1/60 sec. to 1/250 sec. there are 2 increments, so we open up
the aperture by 2 f-stops, going from F4 to F1.8. Note that the camera would
give proper exposure at 1/60 sec. at F4, 1/125 sec. at F2.8, and 1/250 sec.
at F1.8, since all three aperture/shutter speed combinations allow the same
amount of light into the camera. [Some digital cameras provide a 'Program Shift'
function to allow that very shifting of aperture/shutter speed combinations
in tandem.]

F1.8	F2.8	F4	F5.6	F8	F11	F16
1/250	1/125	1/60	1/30	1/15	1/8	1/4

Of course, in a digital camera set on Auto mode, you can select Sports scene
mode, and the camera will automotically select a fast shutter speed and the
appropriate aperture. Likewise, in Shutter-Priority mode, you can choose which
shutter speed you want (fast or slow), and the camera will select the appropriate
aperture for proper exposure.

In our example above, let's say the lens on your digital camera only opens
up to a max. aperture of F2.8. If you now select 1/250 sec. (in Shutter-Priority
mode), the camera will not be able to select an aperture larger than F2.8 (in
our example, it really needs F1.8). It would then give you an "underexposure"
warning. If you go ahead and take the picture anyway, your picture would be
1 f-stop underexposed (i.e. you really needed to open up the aperture by 1 more
f-stop for correct exposure).

Similarly, if you select a shutter speed of 1/4 sec. and the lens only closes
down to a min. aperture of F8 (in our example, it really needs F16), the camera
would give you an "overexposure" warning. If you go ahead and take
a picture anyway, your picture would be 2 f-stops overexposed (i.e. you really
needed to close down the aperture by 2 more f-stops for correct exposure).

[Editor's note: There is a third variable in the above example which we have
purposefully not introduced. This is the sensitivity of the image sensor --
the ISO. We'll cover this in a later tutorial.]

How Is A Small Minimum Aperture Relevant?

A small minimum aperture is preferable to a larger one since it also
gives the photographer more latitude in the kind of pictures that can be taken.

Suppose we want to take a picture of flowing water. As mentioned above, to
depict flowing water, we usually want to use a slow shutter speed so that the
water blurs. It is this blurring that makes the picture so effective in depicting
water motion.

So, let's say the light meter in your digital camera calculates that for proper
exposure on a bright sunny day, you need an aperture of F8 and a shutter speed
of 1/125 sec.

F8

1/125

Well, if you decide to use a slower shutter speed (say, 1/30 sec.), this means
that you have to compensate by closing down the aperture to allow less light
in.

It makes sense really. Since you have increased the time the shutter remains
open to allow light in, you must compensate by allowing less light in to expose
the image sensor in that longer amount of time, if you still want a properly
exposed picture.

But, what if the lens on your digital camera closes to a minimum of F8? You're
stuck at the shutter speed of 1/125 sec. If you use 1/30 sec. at F8, your picture
will be overexposed, i.e. burnt out. At 1/125 sec. and F8, your picture
will be properly exposed but the fast shutter speed will freeze the water motion
and you won't obtain the blurring effect you desire.

If the lens in your digital camera closed down to F16, presto, your problem
is solved! 1/125 sec. at F8 is equivalent to 1/30 sec. at F16, which means that
you would have a perfectly exposed purposefully-blurred-for-effect flowing water
shot. [If your lens does not close down to F16, you could use a Neutral Density
(ND) filter to reduce the amount of light coming into the lens, and thus allowing
you to use a slower shutter speed.]

F1.8	F2.8	F4	F5.6	F8	F11	F16
1/2,000	1/1,000	1/500	1/250	1/125	1/60	1/30

[Editor's note: There is a third variable in the above example which we have
purposefully not introduced. This is the sensitivity of the image sensor --
the ISO. We'll cover this in a later tutorial.]

Aperture and Depth of Field (DOF)

We mentioned this above but feel it is important enough to repeat in its own
paragraph.

The Depth of Field is the distance wherein objects are in focus.

There are times when you desire a great depth of field, i.e. where objects
both close to you and far from you are in focus. This is especially true when
you are taking a landscape picture and want as much as possible to be in crisp
focus.

Then there are times when you want to isolate your subject, as when you are
taking a portrait and want your subject to be in sharp focus but the background
to be out of focus. In this case, you desire a shallow depth of field.

One way to influence DOF is by selecting the appropriate aperture.

The rule of thumb is this:

• Select a large aperture (or small f/value or small aperture value), e.g.
  f/2.8, to obtain a shallow DOF
• Select a small aperture (or large f/value or large aperture value), e.g.
  f/8.0, to achieve great DOF

Here are some real images that demonstrate the use of aperture to influence
DOF:

Aperture and Depth of Field (DOF) AF area is on yellow pistils of flower in front
Shallow DOF	Great DOF
Note how the use of a large aperture (small aperture value) throws the flowers in the background out of focus. Focus has to be precise.	Using a small aperture (large aperture value) extends the DOF from the foreground all the way to the background.
49.8 mm, Av, Spot, 1/30 sec., f/3.5, +0.7EV, Macro, Tripod used	49.6mm, Av, Spot, 1/5 sec., f/11, +0.7EV, Macro, Tripod used

Note: Since we are on the subject of DOF, DOF also changes with focal length.
Use a small focal length to increase DOF, a longer focal length obtain a shallower
DOF. I.E. if you zoom, the DOF decreases. [OK, to be technically correct, focal
length does not really affect DOF, but gives the effect that it does. And, that's
good enough for us since that's what we're after. We'll cover DOF in a later
tutorial.]

Due to the small image sensors used, digital cameras use such small focal lengths
that it is very difficult to obtain shallow depth of field even when using a
large aperture. In the example above, we used a large aperture AND a long focal
length (telephoto macro) to achieve a shallow DOF.

Recap

A large maximum aperture is a good thing. It allows more light to reach
the image sensor, and so allows you to use a faster shutter speed. A faster
shutter speed freezes action and negates the effect of camera shake, resulting
in pictures that are not blurred.

Another advantage of a large maximum aperture is to provide a shallow depth
of field. This allows the background to blur nicely thus isolating your subject
(especially effective when taking portraits).

A small minimum aperture is also a good thing. It allows you to use
a slow shutter speed on a bright sunny day. A slow shutter speed allows you
to depict motion.

Another advantage of a small minimum aperture is to increase the depth-of-field.
An increased depth-of-field allows you to take landscape pictures where as much
of the picture in the foreground and reaching all the way to the background
(usually, 'infinity') is in sharp focus.

 

Our Readers
Write Back

We don't pretend to be experts in all aspects of digital photography and
therefore are very happy to learn together with our readers. Their feedback
to this article are published below.

From: Robert Counts

The only unanswered question in my mind is about the recipes given for aperture and shutter spead at the bottom section of the "Good ApetureRange" section. My question along the line of: Are these aperture recipes set? I noticed that in the set of photos below where depth of field is being illustrated, the aperture/shutter specifications are different from the ones in the diagrams above, but the photos still look good. I know that this is an answer that will come with shooting experience, which is what I need to do on my own, on top of reading tutorials like this, but that further explanation would be really helpful for us beginners. Thanks so much for making this great tutorial available!

Editor: Notice that the article talks about Good Aperture Range. We are suggesting
what a good range is. There is no such thing as a 'good aperture' -- an
aperture is basically just a hole that allows light in.



As far as the aperture range is concerned, a large aperture allows more
light in and therefore allows us to take natural light picture (i.e. without
flash) when there's not much light to go around. That's good. A large
aperture also allows us to shorten the depth of field, important for
occasions when we want to blur the background and have our subject stand out

in sharp contrast to the background. That is very good!




A small aperture allows us to limit the amount of light that comes into the
camera and this allows us to use a slower shutter speed in bright lights for
occasions when we want to depict motion, e.g. flowing water. [When it's still too bright, photographers use Neutral Density filter(s) to reduce the amount of light coming into the camera.] More importantly, a small
aperture also increases depth of field and ensures that objects from near to
far are all in sharp focus, as we like to have in landscapes. That is very good!



The sample images show that we can take good photos at all apertures. But a
good range of apertures allow us to take more good photos, especially
those that depend on depth of field.

Source: http://www.photoxels.com/

What is Shutterspeed?

Shutter speed is a setting on your camera which controls the length of time the shutter is open, allowing light through the lens to the sensor inside your camera. Shutter speeds can go from very small fractions of a second, to several seconds long on most cameras.

So why would you want to change it?

On a very bright day when there is a lot of light, if you allow the shutter to be open for too long then too much light will get to the sensor. When this happens you end up with pictures that are very pale and almost all white. This is known as being Over Exposed.

Let’s say, for a simplified example, that to get a perfectly exposed image on a bright sunny day, ignoring all the other camera settings, that you need the shutter to open for half a second. This half a second allows just the right amount of light through to the sensor to get a well exposed imaged.

Now, as the day goes by and you get to the evening, there isn’t as much light about. So if you took a picture and your shutter speed was still set at half a second you would end up with a very dark image, or an Under Exposed image. This is because not enough light got through to the cameras sensor in that half a second. So in order to compensate against lower levels of light, you would need to keep the shutter open for longer.

You can see an example of under and over exposed images here.

This may seem straight forward enough, but the longer the shutter is open, the more chance there is of ending up with a blurred image. The slightest of movements while the shutter is open will register as a blurred effect. Sometimes this can be the desired effect, but most of the time you want a sharp image. Using a tripod, sitting the camera on a solid object like a wall or the floor or holding the camera against a solid object like a big tree or wall can help reduce the chances of getting blurry images.

Most digital cameras will have a fully automatic setting where it decides what settings are best, so all you have to worry about is pointing the camera in the right direction and pressing the button. This may be the mode you use all the time, but it’s well worth experimenting with these settings yourself to see what effect they have. Once you start to understand these settings and what they can do to your image you will open up a whole new range of photographic opportunities and much more creative and pleasing photos.

Source: http://www.photography-basics.com/

What Is Photography

Photographs are amazing.  Through photographs, we preserve history - our child's first steps, a decaying landscape, or rare and endangered animals.  We use photographs to recall the first steps on the moon, the inauguration of a new president, the lifting of a flag on a far-away hill during war.  Mothers laboriously decorate large scrapbooks just to protect their precious memories.   Photographs evoke the essence of places we have not been, we perhaps will not return to, and should never forget.  

With a photograph, I can bring someone from his or her spot on the globe to mine.  They can stand with me in the midst of a pine forest or walk in hushed silence through the musky light of a swamp.  In reverse, through the images of others, I have walked across hot, sandy deserts; I have stood on immense mountaintops, and pushed my way through steamy rainforests.  Photographs have introduced me to families, mothers and fathers I have never met, and told the story of lives intertwined forever.  In short, photographs are very important.

Photographs "become" through making choices, and great photographs become through making right choices.  Right choices are the direct result of the knowledge of the photographer.  Great photographs are NOT, however, strictly the result of owning fancy equipment.  Anyone using most any camera can take an incredible photograph.

Camera

Superior photographs come from photographers who know how his or her camera functions.  A skilled photographer takes the time to read the manual and familiarize themselves with everything that camera will do.  After all, if you don't know what your camera will do, then how can you do it?  Taking this statement even one-step further, a truly skilled photographer will "one up" the camera and get it to do things it is not supposed to do.

In the first photo contest I won, I used a Polaroid PDC-640 digital camera I purchased from a family member.  The maximum pixel size for this camera was 640 x 480; its given macro distance was six to twelve inches.  Through the advice of a kind man I met on the web, I learned how to shorten my macro distance by holding a magnifying glass in front of the lens.  The results were startling, and the win a few months later in an online monthly contest extremely gratifying.  My little handheld point-and-shoot beat out all the more expensive digital cameras in that contest. 

I won because I knew how to extract the best product from that particular camera.  I knew what it would and would not do.

Knowledge

I won that contest with my camera set on Auto.  I allowed the camera to choose the settings it needed to make the image, and I gave it no further thought.  Truth be told, I use Auto a lot even today.  However, something must be said about knowing how a camera captures images.  

Eventually, every photographer runs into a scene they really would like to photograph, but their camera seems to be doing the wrong thing.  Perhaps you are in a dark room and are handholding your camera.  Unless you know how to adapt your camera to the situation, your images will probably come out blurry.  Having the knowledge within oneself on what to change, on how to correct your settings will prevent you from losing that moment.

We are all of us insufficient in learning somewhere.  At no point in time do I ever feel I know enough or have learned it all.  Even the highest-paid most professional of photographers, even those with thousands of dollars in lenses and software, have to further educate themselves at some point.  To put it poetically, expensive equipment does not a good photographer make.

Passion

Photographs are visual artwork.  They take something ordinary and elevate it to a position of honor.  A strand of barbed wire fencing becomes romantic; the seed of a common weed fires the imagination.

Famed landscape artist, Ansel Adams, once said, "A great photograph is one that fully expresses what one feels, in the deepest sense, about what is being photographed."  I also like a quote I once read by photographer David Hum.  "Photography is only a tool, a vehicle, for expressing or transmitting a passion in something else."  What images I capture should express the passion I feel for that scene, that object, or that moment in time.  When other people view my work, they should know in part who I am as a person.

It seems simple to say it, but photography should always be fun.  It is great to have ones work published in the marketplace and it is nice to make money from it, but at the same time, I should always enjoy the process.  My passion for photography, my passion for the photograph itself and thus for the subject matter, must communicate itself to the viewer.  An image of a spider spinning her web should fascinate others as much as it did me when I took it.

Connections

Photography connects people - through interests, locations, and cultures.  It spans time and distance as a bridge between worlds.  I have learned much about life, nature, and people by connecting myself with photography groups and viewing online galleries.  At the same time, the people I have met come from all levels of photography.  There is nothing as heartwarming as meeting someone who has traveled further than I and photographed things I will never see in person, yet they are still humble, willing to share their experiences, and teach others what they have learned.

None of us are ever above the other in photographic society.  Owning a DSLR does not make a photographer greater than the father with a point-and-shoot who just wants to remember his son's ballgame.  It will create more opportunities for taking better photos with less effort, but in the end, it doesn't make you any greater.  

My attitude in public, my willingness to share what I have learned, will have a direct reflection on of what others think of my work.  Kindness goes a long way to create a persona other people like enough to spend their time looking at what I have done.  In the end, our behavior furthers our photographic goals, no matter how large or small they may be.

Without a good foundation of the principle elements of photography, both in its physical and mental processes, the resulting photograph will fall far short of its goal.  To make a superior photograph, to take that one shot that for your lifetime you are so proud of, is possible for anyone who picks up a camera.  It does not come from the equipment alone, though that will have an effect on the result.  Someone with an expensive camera can still take a bad photograph.  Instead, it is that this photographer had a willingness to learn, a passion for his craft, and an ability to connect with his viewers.  

This photographer will make the biggest impression, and his photographs are those that will be the most remembered.

Source: http://www.steves-digicams.com/