Photography Guide for Beginners – Chapter 4
The Depth of Field
You have no doubt come across the term Depth of Field (DOF) if you are into photography. However, you may not have an understanding of how it can affect the quality of your photos. The depth of field is generally the zone within your photo that appears to be in focus. In every image, there is an area just behind and in front of the picture, which is in great focus.
The zone varies from image to image. In some pictures, the zone of focus is quite small, which is called a shallow depth of field. In others, it is quite huge, which is known as a deep depth of field. Three factors affect the depth of field. These are:
1. Aperture
2. Distance of the subject from the camera
3. Focal length of the camera’s lens
The Aperture’s Effect on the Depth of Field
Aperture is simply the access that light has to camera sensor. The size of the aperture controls how much light enters the lens. The aperture is the simplest means by which to control the depth of field for any shot.
Large aperture means a shallow depth of field while a small aperture means a larger depth of field. To simplify things, keep in mind that the lower the f-number, the smaller the depth of field.
The Effect of Distance on the Depth of Field
As the subject gets closer to the camera, the depth of field becomes shallower. Thus, as you move further away from the subject, you are able to increase the depth of field.
The Effect of Focal Length on the Depth of Field
The focal length simply refers to by what margin the lens can magnify an image. In the simplest terms, a longer focal length leads to a shallower depth of field.
What about Point and Shoot Cameras
Even when you are using a point and shoot camera, you can control the depth of field. In the scenes mode, look for the portraits setting. This will provide you with a narrow depth of field. In the same mode, choose landscapes, represented by a mountain. This will give a deep depth of field.
When using a DSLR camera, you can still control the depth of field with automatic shooting mode enabled. You can go for the Aperture Priority mode and set the aperture. That will allow you to control you DOF and the camera will set the shutter speed.
Is Setting the Depth of Field for Each Situation Possible?
This is possible but because when you change the aperture, it will affect the shutter speed and the result may not be what you desire. For instance, by reducing the aperture to increase the depth of field, it could slow down the shutter speed that leads to blurry images. You have to understand how all the setting works to get control over the DOF.
Is the Depth of Field Equally Distributed between the Front and Back of a subject?
In most cameras, the DOF is distributed a third in front of the camera and two-thirds behind the focal point. However, as the focal length increases, the distance between the front and back of the camera becomes equal.
How Understanding the Depth of Field Will Affect Your Photography
Being able to control the depth of field is one of the most essential tools for great photography. The reason for this is that having sharp images is amongst the most important factors for getting a good shot. Knowing how to make the parts of your image that you want to stay sharp to do that and knowing which parts to blur is great for art.
When to Use a shallow Depth of Field
A shallow DOF is a great way to make the subject stand out and is great for taking portrait photos. A shallow DOF can also be great for wildlife photography. It can help you define the animal that you want from the rest of the wildlife. The reason for these is that most opportunities for photographing wildlife are in low light and a bigger aperture size provides you with more light.
Sports photography is another area that could benefit from a shallow DOF. It is especially helpful in helping to separate the athlete from the background to give them more attention. You should combine it with a fast shutter speed so that you are able to freeze the action.
When to Use a Deep Depth of Field
When taking landscape photos, you should strive to get as much of the scene in focus as possible. That will entail making use of a wide-angle lens and a small aperture. That way, you are able to maximize the depth of field and capture as much of it as possible.
How to Determine the Depth of Field
Many charts online can help you calculate the depth of field for your lens and camera. You can use one of the many apps available for smartphone users. Most cameras have DOF preview setting. It gives you what to expect once you check via an eyepiece. It is probably the easiest method to check the DOF. However, the image may appear darker via the eyepiece.
Can You Adjust the DOF to Get Everything in Focus?
This is possible using the hyper-focal distance. With the hyper-focal distance, the depth of field extends from half the distance to the focal point to infinity. If you are lacking a DOF calculator, always focus a third of the way into the scene. With an aperture setting of f/11 and a wide-angle lens, you can maximize the DOF.
The Depth of Field and Macro Photography
Since many macro images are produced in low light and a long focal length, the depth of field is usually quite shallow.
The lens should be adjusted to the smallest aperture that light would allow. You may also need to increase the ISO to allow the image to be properly exposed. In most macro images, the DOF is usually quite tiny. With such a narrow focus, the use of a tripod may be necessary. The reason for this is that the slightest movement will cause the macro subject to go out of focus.
Understanding Bokeh
Bokeh is of Japanese origin and it means blur. An effect occurs because of the out of focus areas beyond the DOF. It is used to refer to the circular shapes that result from the shapes of the aperture. It occurs when the aperture is wide open or when the background is distant enough.
Depth of Field in Summary
In summary, the amount of inches of the DOF is not worth getting hung over. That would completely take away the joy of photography. It is much more crucial to tell when you require a small DOF and how you can create it and vice versa. The beauty of modern cameras is that you can take a photo and then review it on the LCD screen.
This is much easier than using a DOF calculator. If you find that it is not what you desire, you can then make the necessary adjustments. Understand the factors that will affect your DOF are what will give you artistic freedom. The only way to perfect it is to practice often. When it comes time for the photo shoot, you will not need hours to adjust.
