In photography, bokeh  is the aesthetic quality of the blur produced in the out-of-focus parts of an image produced by a lens .Bokeh has been defined as “the way the lens renders out-of-focus points of light”. Differences in lens aberrations and aperture shape cause some lens designs to blur the image in a way that is pleasing to the eye, while others produce blurring that is unpleasant or distracting—”good” and “bad” bokeh, respectively.

Bokeh occurs for parts of the scene that lie outside the depth of field. Photographers sometimes deliberately use a shallow focus technique to create images with prominent out-of-focus regions.

They way that bokeh is created is by focusing the camera on an object in the fore ground of the image and having lights in the back ground of the image, by focusing the camera in the foreground image it creates as shallow depth of filed thus causing the lights in the background to blur creating the bokeh.

Definiton

In photography the distance between the nearest and the furthest objects giving a focused image.

What is Depth of Field

Depth of field is the zone of acceptable sharpness within a photo that will appear in focus. This zone will vary from photo to photo. Some images may have very small zones of focus which is called shallow depth of field. Others may have a very large zone of focus which is called deep depth of field. Three main factors that will affect how you control the depth of field of your images are aperture, distance from the subject to the camera, and focal length of the lens on your camera

Depth of field (DOF), also called focus range or effective focus range, is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image.  A camera can only focus its lens at a single point, but there will be an area that stretches in front of and behind this focus point that still appears sharp. This zone is known as the depth of field. It’s not a fixed distance, it changes in size and can be described as either shallow or deep.

Because depth of field has an impact on both the aesthetic and technical quality of a picture. Sometimes you’ll want to use an extensive depth of field in order to keep everything sharp.

A classic example is when you’re photographing a landscape, where generally the most desirable outcome is to capture detail from the foreground to the horizon.

Other times, a shallow depth of field will be preferable. It enables you to blur background and foreground details, causing distractions to melt away and allowing you to direct viewers to the focal point in a picture.

Aperture

Aperture refers to the access given to light from the lens to the camera sensors. The size of your aperture controls the amount of light entering the lens of the camera. Using aperture is the simplest way to control your depth of field as you set up your shot. The lower the f-number, the smaller your depth of field, meaning less of the image will be in focus. On the other hand, the higher the f-number the larger the depth of field should be and most of the picture will be in focus.

Distance from your subject

The closer your subject is to the camera, the shallower your depth of field becomes. Therefore, moving further away from your subject will deepen your depth of field.

Technical: this image is very sharp and still, this suggests as fast shutter speed was used. As this photograph is a style of environmental portraiture, natural lighting would have been used so the photographer could easily move around depending on the scene.  Documentary photography generally means the photo has not been edited because it is meant to show the truth. we can see a high contrast in the photograph, there are extremely white areas for example the four lines on the edge of each window which draw our eyes to the passengers. there are also very dark shaded areas which help to dramatize the image and add depth. The depth of field is interesting because we get the idea that the people in tram are looking directly at the photographer, this suggests he was close to the subject.

Visual: This is a black and white photo because at the time colour photography was not commonly used, however I think this adds depth and some interesting details to the photo. The dream America was thought of as bright and colourful, the idea that all of the colour had been stripped from this image could suggest that black and white reveals the truth. The tone of this photo is very dark which helps the few light areas stand out even more. Although most of the detail in this image is in the central horizontal third there is a lot of texture coming from the bottom of the image. the dents in the metal show imperfections and give the image a more urban and industrial look. This image has a clear line of symmetry down the middle, the regularity of the tram windows helps us to seen the difference between the people in them. The windows also line up with the rule of third which give the photo a very regular and organised look, this links to