jeudi 23 mai 2013

How To Make Use Of Perspective in Photography

By Luke Walker

If you look at a photo whether it be in print or on a screen, it goes without saying that what you are seeing is a two dimensional representation of a three dimensional scene. The two dimensional picture is an illusion and our brains decipher the information to work out the 'depth'. As photographers we can manipulate perspective to resemble a sense of depth and scale in photos.

How To Define Perspective

In photography, perspective is defined as the sense of spatial relationships between things and their dimensions in relation to the position of the viewer, producing a sense of depth. Here are our top ten tips on how to use perspective.

1. Blocking Subjects Partially

It is an obvious statement, but when one object is partially obstructing your view of something else, your mind tells you that the partially hidden object is further away than the object obstructing it.

By relating their sizes we can perceive the depth. We call this overlap perspective.

2. Relative size

As an object gets smaller, our minds decipher this to tell us that the object is further away from the viewpoint where the photo was taken. We already know rough sizes of familiar objects, such as cars, trees, humans and houses, so upon seeing a person who is five times taller than a house, our mind lets us know that the person is much closer to us than the other object is. Our brain processes the information based on familiar objects compared with other objects in the photo to imagine the distance and depths of relative objects. This is called scaling.

We can use some interesting photography techniques by placing several objects at various distances from the viewpoint and give the illusion that they are on the same plane. You can get some peculiar images.

Having a single familiar object in a picture enables us to work out the sizes of other things in the frame in relation to that one familiar object. Think about how many pictures you have seen of people holding a fish they caught smiling at the camera. They do this so that you can see how large the fish is in comparison the people. Think about a photo of a man standing among some huge leaves in the jungle, which are bigger than he is. This will shock your mind because we we are used to seeing leaves that are smaller than our hands.

3. The Vanishing Point

The human eye judges depth by the way lines and planes converge at a point inside or outside of the picture. This is known as linear perspective.

Fish eye lenses create images of objects which appear smaller at the edges of the picture than they would seem in reality. On the other hand, things in the middle of these pictures appear much larger than they would in real life.

Parallel lines in a picture which move away from the viewpoint appear to be converging or meeting with each other at a certain point, known as the vanishing point. You see this all the time in photography. A typical example is a photo of railway tracks converging at some point far away close to the horizon.

4. The Lens Axis Level

Horizontal lines moving across the lens axis level appear to be straight, and all other horizontal lines above and below this level appear as curved lines. In reality, we perceive all lines as being straight, whether they are on, above or below the lens axis level. Rectilinear lenses also reproduce lines as being straight.

5. Perspective Projection Distortion

All pictures could be subject to perspective projection distortion. This is when we use panoramic and fish eye lenses to deliberately produce warped perspectives to create interesting effects.

6. Reduced Colour Quality, Definition And Sharpness

Due to reduced contrast, scattering of light and other factors, our eyes cannot define objects in the distance as easily. Objects further away are harder to define because of light scattering and reduced contrast as well as other factors. Knowing this allows our brains to make more sense of distance. In photography, we can take this knowledge and use it to our advantage to create photos where objects at certain distances appear to have less definition and contrast. We do this by controlling the depth of field. One of the main ways that they do this is by focusing the camera lens slightly shorter than infinity to make the objects furthest away look out of focus. This gives the viewer a sense of the depth and distances of various objects in the picture.

Our brains make us believe that when see these blurred, less colourful objects we are looking at something further away than the brighter, vibrant objects closer to the foreground.

Prior to taking a shot, you should decide whether you are trying to emphasize the depth of the scene or not.

7. Focus And Depth Of Field

By adjusting the F-stop value of the aperture, the focus distance and the focal length, we are able to control the depth of field. The depth of field (DoF) defines an area where objects are in focus in the picture. Anything closer to the viewpoint than this area, or further away than it will be blurred. A common mistake of beginner photographers is to try to get everything in the picture to appear sharp. They tend to user smaller apertures to maximize the depth of field. This can sometimes work well, but it is generally not seen as something more seasoned photographers like to do.

8. Isolating an object

One way to get nice effects in photography is to isolate an object from its environment. You could do this with a wide lens, which will divide the scene into different layers. Sometimes you will find that the background is unappealing. To resolve this issue, we can sometimes select a tiny DoF so that all objects behind the main object are less in focus. These objects are now less significant in the picture.

9. Compression

One of the most overused types of lenses in photography is the wide angle lens, which makes pretty bland-looking perspectives lacking in definition. The depth from a wide angle lens compresses the scene. It is far better to use a medium tele lens, because it is capable of emphasizing depth.

10. Layers

If you like taking shots of mountains and other landscapes, a great approach is to use the notion of layers. These mountains are usually the dominating feature of a photo. You can make your pictures much more interesting by using addition layers in the foreground and the centre.

No familiar objects (trees, people, etc.) in a shot make it hard for the view to get a sense of scale. One thing you can do is wait until someone enters the frame, or ask your friend to stand in the frame.

Thanks for reading and don't forget to make use of some of the points written here next time you are shooting.

About the Author:

Aucun commentaire:

Enregistrer un commentaire