Welcome to the sixth installment of the monthly project series: Advancing Photography. Tom Persinger, co-founder of the AP column as well as a photographer, writer, and the founding Director of F295, joins us again this month for a project about points of focus and depth of field.
About the project series: Advancing Photography
Advancing Photography (AP) is a new series of monthly articles on photo.net that explores various topics of photographic practice. Each new project will provide the following for context, information, and historical background if appropriate:
- A short insight into a key photographic concept
- Several illustrative examples
- A few links to important historical imagery that demonstrate the concepts
- An exercise to help refine your understanding of the concepts
- An invitation to then add your photos to the bottom of the thread (similar to the No Words Forum format)
NEW! At the end of each month, the guest instructor will select the best execution of the project. That photographer will receive a large canvas print of their image from CanvasPop (value not to exceed $100).
(Note: Canvas print size may be limited to resolution provided unless photographer can send higher resolution upon notification of selection. Alternatively, photo.net may opt to provide a gift card to our fulfillment partner CanvasPop to upload directly to their site. Additional terms and conditions apply.)
We hope that you’ll explore these activities and consider posting your images to share how you applied the article’s ideas and principles. The goal of the AP series is to provide information and exercises to advance and hone your photographic skills.
In our last monthly project we discussed the short exposure and how its use can seemingly stop the very flow of time. As we move forward, remember to try to integrate and continue practicing the concepts from previous exercises. So far, we’ve covered such diverse topics as the edge of the frame, the quality of light, textures, reflections, and using shutter speed to capture motion. Each of these skills can work together and through continual application will become second nature to you and elevate your work. This month’s project examines the considered use of depth of field. A short lesson, three things to try, useful historical examples, and a few sample images will illustrate this month’s key concepts.
Project: Depth of Field
by Tom Persinger
A Short Lesson
Depth of field is defined as the area of a photograph that appears sharply focused. An image with a shallow depth of field is one with a smaller range of focus, and one with a long depth of field means there’s a longer range of focus. An image’s depth of field depends on several things including the size of the aperture, the focal length of the lens, and the distance the camera is positioned from the subject.
The aperture is how light enters the camera to create an image on the sensor or film. Aperture size is generally referred to as an f/stop, and on a standard DSLR lens it might range from f/1.8 to f/32. The larger the number (e.g., f/32), the smaller the aperture and the less light will enter the camera, but the depth of field will be longer. Conversely, the smaller the number (e.g., f/1.8), the larger the aperture, the more light will enter the camera, and the shallower the depth of field. Aperture has an inverse relationship to shutter speed. Smaller apertures (higher numbers) will generally require slower shutter speeds while larger apertures (smaller numbers) will demand faster shutter speeds.
The focal length of the lens also impacts depth of field. Wide-angle lenses with shorter focal lengths have a longer depth of field than telephoto (longer focal length) lenses. This is one reason many street photographers favor wide-angle lenses in their work.
And finally, the distance between the camera and the subject impacts the image’s depth of field. The closer the distance between the two, the shallower the depth of field; the further the distance, the longer the depth of field. It’s important to remember that each of these factors needs to be considered simultaneously in order to accurately control your image’s depth of field for maximum impact.
Where we choose to place focus in the image is another important consideration and closely related to depth of field. We often instinctively focus on the image’s main subject, but we might consider experimenting and changing that point of focus. Sometimes simply adjusting the point of focus to a nontraditional point can help to create images that defy expectation, create excitement, and stir a sense of surprise in the viewer.
Three Things to Try
1. Shallow depth of field: Make a photograph in which the field of focus is not long (use a large f/stop). Notice how the placement of the focal plane changes the image and how it portrays the subject to the viewer.
Shallow Depth of Field: f/1.4, 1/40 sec, ISO 800.
In this example we place focus on the lens of the SX-70 and make it the star of the photograph. The soft blur radiates out from that point and creates a wonderful focus for our eye to rest.
2. Long depth of field: Make a photograph in which the field of focus is long (use a small f/stop) and the entire image is in crisp focus. Notice how this image feels different than one with shallow depth of field. (It’s sometimes useful to make the same image with both a shallow and long depth of field so you may directly compare them).
Long Depth of Field: f/16, 1/4 sec, ISO 4000.
In this image, we shifted to a long depth of field which keeps everything in a fairly equal plane of focus. Notice how the image becomes less dramatic and focused. We can now clearly see all of the items that fill the frame, but at the expense of one clear focal point.
3. Combine depth of field with a nontraditional point of focus: Create an image in which you move focus from the area that’s expected to one that is unexpected. Combine this with a shallow depth of field to reveal your subject(s) in a new and surprising way.
Shifting Focus: f/1.4, 1/40 sec, ISO 800.
Here, we shift focus to the old Royal typewriter that sits on a shelf behind the camera. The viewer naturally expects to find the focus point on the prominent object in the foreground, but by shifting it in this fashion, we defy the viewer’s expectations and create a stronger sense of mystery and narrative.
Over the next three weeks, make 50-75 images using the ideas presented here for working with various depth of field settings and choose one image to share with us. Carefully consider what you want to reveal and how the considered use of a depth of field combined with your intended point of focus will help you accomplish your goals. How do your decisions impact the final image? How do the decisions impact the viewing experience? Please post your best image from the exercise in the comments field below!
Continue reading for historical examples and more example images from Tom Persinger to inspire your work.
Some Interesting Historical Examples
Many photographers make use of a long depth of field to create sharp focus throughout the entirety of their images. This is often a safe and effective strategy, but when used judiciously, shallow depth of field can also give your images a unique signature and help focus the viewer’s attention.
In early portrait work, depth of field was mostly shallow due to the nature of the materials with which photographers worked. Plates and early film were not terribly light sensitive and usually required long exposure times. In an effort to decrease those exposure times, many early photographers would often set their lenses to the maximum aperture.
Juliet Margaret-Cameron’s 1867 photograph of Sir John Herschel is a good example of shallow depth of field. In early portraits, focus was usually placed on the subject’s eyes and it would gradually soften over the rest of the image. In Cameron’s photograph, notice how Herschel’s hair is softly blurred as well as his shirt and even parts of his cheeks. For the past several years, the contemporary making of portraits in this style has been popular with those interested in the use and exploration of the wet plate collodion process.
Portraiture in the mid to late 20th century, however, generally favored a longer depth of field. Photographer Yousuf Karsh produced a terrific catalog of portraits that were nearly all in crisp, sharp focus (and were often characterized by terrific qualities of light). Images like his 1948 image of Albert Einstein utilized a longer depth of field in which the entire subject is featured in crisp, sharp focus.
Duane Michals’ double portrait of Andy Warhol and his mother Julia Warhola offers an interesting double-take look at what happens when you combine the considered use of depth of field and placement of focus. Notice how our perception of the image changes in each image depending on which subject Michals has focused the camera.
Most land- and cityscape photographs favor a long depth of field. Ansel Adams, Edward Weston, and the rest of the f/64 group made hundreds of crisp images through the use of tiny tiny apertures. This trend has continued through the present day. Such notable photographers such as Bernd and Hilla Becher, Thomas Struth, Andreas Gursky, Edward Burtinsky, and many others have created catalogs of images in which the focus across the entire image plane is crisp. There are many examples online, but Burtynskyâs Homestead #39 is an interesting contemporary illustration.
This image is a good example of a shot that could have been made with either long or short depth of field with different but still strong impact. The fence is a bold enough object to hold its own in a situation like this where the depth of field is long and most of the frame in focus. It could have also been shot with a shallow depth of field effectively (f/13, 1/30 sec, ISO 200).
Placing focus on this tennis net handle provided opportunity for multiple decisions. Focus could have been placed on the handle, the spool, or the net. In this example I chose to focus on the wire spool for its texture and visual interest. The handle is out of focus, but it’s not distracting as we become interested in the points beyond (f/1.8, 1/4000 sec, ISO 200).