FOCAL LENGTH / DEPTH OF FIELD / FOCUS

Focal length is represented in mm. It is a calculation between the focal point - where the light rays converge to form a sharp image - and the digital sensor / film
 The focal length tells you how much of the view will be captured; the bigger the focal length, the narrower the view and higher the magnification - how much the camera is zoomed in.
 You can adjust focal length by twisting the lens of the camera.


Depth of field

Definition: the distance between the nearest and the furthest objects giving a focused image.

There are two types of depth; shallow and deep. Shallow focuses on a closer object / subject while the background image is out of focus creating a blurred effect. Deep depth of field focuses on the whole frame so everything in the photograph is in focus.

Aperture is used for depth of field. A smaller aperture [f22] focuses on the whole frame and a bigger aperture [f2.4] focuses on a particular object in the frame and blurring out the rest.

Focus and focus points

Focus allows the camera to take a picture in detail. A sharp focus will produce a photograph with sharp detail in the whole frame or a point in the frame. A soft focus produces the opposite effect.

The point of focus can be changed by aiming the camera at what you would like to focus or changing the settings. The point of focus can be changed by pressing the AF button where 9 dots are displayed on the display screen. Choosing different points changes what the camera focuses on.

What is Typology?

The term typology refers to the study of different types. Typology can be used across all industries and disciplines including theology, anthropology, archaeology, linguistics, psychology, politics, education, medicine, farming and more.

Throughout the modern era, photography has been enlisted to classify the world and its people. Driven by a belief in the scientific objectivity of photographic evidence, the logics utilized to classify photographs-in groups and categories or sequences of identically organized images-also shape our visual consciousness. In the twenty-first-century, new digital technologies and globalization have radically transformed the applications of photography, making the reconsideration of photographic information systems ever more urgent.

Focal Length

Focal length is the basic description of a photographic lens. The focal length tells us the angle of view—how much of the scene will be captured—and the magnification—how large individual elements will be. The longer the focal length, the narrower the angle of the photo will be and the higher the magnification. The shorter the focal length, the wider the angle of the photo will be and the lower the magnification.

Focal length is how far in/out the lens on the camera is zoomed. It essentially  crops part of an image out so it isn’t in your final product. Below is a table I found of different ways you can use focal length and what length best suits what environment/style of photography.

What is and how do we Focus?

An image that is completely sharp is said to be in-focus. An image that’s completely blurry is said to be unfocused. In order for a camera to create a focused image, it takes light and runs it through a lens, concentrating the rays on the image sensor inside. The size of the hole the light travels through (the aperture) determines how focused those rays are once they hit the sensor. Smaller holes do a better job of focusing light than larger holes. The focus can be changed automatically or manually depending on how the settings are set on the camera.

There are a lot of situations where you don’t really want the entire image to be in focus. Backgrounds tend to get in the way, and they will distract the viewer from the point you are trying to make. Portraits, look a lot better when the background is somewhat out of focus as well as macro photos too.

Furthermore, it is simply harder to draw attention to things that don’t stand out on their own. When we focus our eyes, we do something similar. You might not notice it, but everything else in your peripheral vision appears a little more hazy or blury. Most of the time, only one part of photographers images should be truly sharp and the rest a little fuzzy so the sharp part stands out.

Range of focus points

There are a variety of different focus points in which can be used in photography. On a DSLR camera you can manually select your focus point using the grid in the image below. each rectangular square represents a focus point and by selecting a certain focus point your camera will mainly concentrate on focusing that area of the picture.

These images clearly show a range of focus points and how the different focus points have an effect on the image, whether it just draws your eyes to a different point in the photograph or tells a different story.

Using focus points i decided to experiment myself. These pictures were taken at the exact same angle and zoom length. The only difference is the focus point.

How do you achieve Bokeh Photography?

To achieve the bokeh affect you will have to Set your camera to Aperture Priority mode. Select the smallest possible aperture (f) number for your lens. Switch your camera to manual focus and manually adjust the focus ensure the whole image is completely out of focus. Zoom your lens to wherever best will suit the photograph.

Examples of Bokeh Photography

This effect is called colour overlaying, achieved by:

1. Selecting an area of your image that you want to adapt
2. Add a colour overlay from your layers panel
3. Reducing the opacity to the appropriate amount or using the blending options
4. Finally, using Free Transform (CTRL T) to rotate, move or change the shape of your new overlay

How to use Focus Points.

To get your images to be crisp, or to allow  the camera and lens work together to change the distance of the lens from the sensor or film in order to control where the captured light converges.

There are many different types of focus points, you can change these focus points on your camera with a button or by selecting them on the screen, the image below will come up on the camera, this shows the range of points in which you can focus your camera on.

The focal length of the lens is the distance between the lens and the image sensor when the subject is in focus, usually stated in millimeters eg. 28 mm, 50 mm, or 100 mm). In the case of zoom lenses, both the minimum and maximum focal lengths are stated, for example 18–55 mm

How do you know when to use focal length ? 

Focal length is how far in/out the lens on the camera is zoomed. It  crops part of an image out so it isn’t in the final product/image.

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.