Perspective in photography is a very important composition technique
One important thing to remember here, the size of the aperture has a direct impact on the depth of field, which is the area of the image that appears sharp. A large f-number such as f/32, (which means a smaller aperture) will bring all foreground and background objects in focus, while a small f-number such as f/1.4 will isolate the foreground from the background by making the foreground objects sharp and the background blurry.
Image on left shot at f/2.8, Image on right shot at f/8.0
As you can see, just changing the aperture from f/2.8 to f/8.0 has a big effect on how much of WALL-E is in focus and how visible the background gets. If I had used a much smaller aperture such as f/32 in this shot, the background would be as visible as WALL-E.
Another example:
Mailboxes - Aperture set to f/2.8
In the above example, due to the shallow depth of field, only the word “Cougar” appears sharp, while everything else in the front and behind of that word is blurred. If I had used a larger aperture such as f/1.4 and focused on one of the letters, probably only that letter would have been sharp, while everything else would have been blurred out. The larger the aperture, the smaller the area in focus (depth of field).
4) Lens Apertures: Maximum and Minimum
Every lens has a limit on how large or how small the aperture can get. If you take a look at the specifications of your lens, it should say what the maximum (lowest f-number) and minimum apertures (highest f-number) of your lens are. The maximum aperture of the lens is much more important than the minimum, because it shows the speed of the lens. A lens that has an aperture of f/1.2 or f/1.4 as the maximum aperture is considered to be a fast lens, because it can pass through more light than, for example, a lens with a maximum aperture of f/4.0. That’s why lenses with large apertures are better suited for low light photography.
The minimum aperture is not that important, because almost all modern lenses can provide at least f/16 as the minimum aperture, which is typically more than enough for everyday photography needs.
This 50mm lens has a max. aperture of f/1.4
There are two types of lenses: “fixed” (also known as “prime”) and “zoom”. While zoom lenses give you the flexibility to zoom in and out (most point and shoot cameras have zoom lenses) without having to move closer or away from the subject, fixed or prime lenses only have one focal length. Due to the complexity of optical design for zoom lenses, many of the consumer lenses have variable apertures. What it means, is that when you are fully zoomed out, the aperture is one number, while zooming in will increase the f-number to a higher number. For example, the Nikon 18-200mm lens has a variable maximum aperture of f/3.5-f/5.6. When zoomed fully out at 18mm, the lens has an aperture of f/3.5, while when fully zoomed in at 200mm, the lens has an aperture of f/5.6. The heavy, professional zoom lenses, on the other hand, typically have fixed apertures. For example, the Nikon 70-200mm f/2.8 lens has the same maximum aperture of f/2.8 at all focal lengths between 70mm and 200mm.
Why is this important? Because larger maximum aperture means that the lens can pass through more light, and hence, your camera can capture images faster in low-light situations. Having a larger maximum aperture also means better ability to isolate subjects from the background.
If you have any questions, comments or feedback, please post them in the comments section below.
How can we show depth and distance in our mages?
Linear Perspective in photography
Converging parallel lines that move away from us appear to
converge at the horizon. Sides of roads and the rails of railroads seem
to merge together at extreme distance. This is an aspect of the relative
size effect. Even though the sides of the roads or the rails are at a
fixed distance they will appear smaller and smaller as they get further
away from us.
When you zoom with a lens but keep the distance from the lens to
the subject the same, there will be no change in the perspective. The
zooming will only change the size of the subjects in the frame.
By using the right combination of distance to the subject as well
as the lens focal length, a photographer can create an image that looks
deep or shallow. The feeling of depth or shallowness is only an
illusion, but it is a very important compositional factor.
Height Perspective in photography
The place where the base of an object is located on the ground in
an image is a clue to its distance from the camera viewpoint. In a
landscape scene the ground or ground plane rises toward the horizon. The
higher up in the ground area of the picture (up to the horizon) the
base of an object is located, the further away it seems from the
viewpoint and the greater its height perspective.
Overlap Perspective in photography
Another way of showing distance in an image is to use overlap
perspective. When subjects within the image are on about the same line
of sight, those objects closer to the camera overlap more distant
objects and partially hide them. It is obvious to the viewer that the
partially obstructed objects are behind the unobstructed objects. If
these overlaps are repeated within the image, they give the viewer a
sense of depth and a perception of the relative distance of the objects.
Introducing ISO sensitivity
The ISO sensitivity (ISO rating, ISO speed) characterizes the sensor or film sensitivity to light. Formerly called ASA rating, digital cameras continue to use the same system introduced a long time ago. It is common to use the term "stop" in photography. One stop in terms of ISO refers to a doubling of our sensitivity. ISO 200 is twice as sensitive as ISO 100 and is therefore "one stop higher." In film photography, we would have to make a decision on the type of film needed before going out on a shoot. One of the great advantages of digital photography is the capability to change the ISO settings for each frame.
Use higher ISO settings with caution. High ISO film is wonderful for low light photography, but they have much more grain then low ISO films. A high ISO setting on your digital camera will also produce more noise in your image.
Modern SLR cameras have very low noise and I would not hesitate to use even higher ISO settings to "get the shot." Digital SLR cameras have less noise than point and shoot cameras at the same ISO setting, since their larger sensor means they are more light sensitive (a large window lets in more light than a small one).
Shutter Speed
The shutter is covering the film or sensor and only when the shutter-release is pressed, do we open the shutter for a pre-determined time to let light pass through our lens to the sensor. We also use "stops" to measure shutter speeds. Each stop doubles the time the shutter remains open and thus doubles the light sensitivity of our camera (e.g. 1/160s is twice as long as 1/320s). For handheld shooting, we require at least 1/(focal length) or shorter to avoid camera shake (if no Image Stabilization is used). For a Rebel XSi with 50mm lens, this means 1/80s or longer (the rebel has a focal length multiplier of 1.6, so 50x1.6=80).
Aperture
The aperture is the size of your lens opening. It controls how much light we let pass to our sensor. Aperture also determines Depth of Field and is measured in stops (f-stops for aperture). Each stop doubles the amount of light we let pass (f/4 is two stops larger then f/8).
Aerial perspective in photography
The farther away from the camera subjects are, the less distinct
they become. This is because the air affects the light as it travels
from subject to camera sensor. Dust particles and water droplets in the
air diffract the light and make the image hazy with lack of contrast.
This effect is known as aerial perspective and can be used to make an
image seem more three dimensional. How marked the effect is on the image
is dependent on the distance.
Aerial perspective is more useful when shooting landscapes rather
than portraits, but the effect can be seen in any picture where the
background is far enough away from the camera. In landscape photography
this effect is more distinct in the afternoon when the air has been
heated during the day. If you want to avoid the effect in landscape
images, shooting at sunrise is recommended.
Rule of Thirds
Imagine that your image is divided into 9 equal segments by 2 vertical and 2 horizontal lines. The
rule of thirds says that you should 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 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.