Know Your Camera: Depth of Field Experiments

Level: Beginner

In photography you learn best by doing. To understand basic as well as advanced concepts, it is important that you experiment for yourself.

In working with the camera, it is essential that you ask yourself the necessary questions and then systematically work out the answer.

The journey to find the answers allows you to develop your intuitive senses and tap into the very essence of your creative spirit. You definitely don’t want to miss this trip!

If you want to go forward in your understanding and utilize many of the special functions of your camera in a more artistic way, then you need to ask yourself one very important question.

That question is: “What if …?” What if I tried it this way? Or, what if I tried it that way? What if I changed the “rules” and experimented by moving this or adjusting that?Just asking the question isn’t enough however.

You need to set up some experiments to try to answer the “what if” question in such a way that you learn what to do … or what not to do.

Experiments: Lenses, Aperture and Resulting Depth of Field

So, how do we see how the various lenses and the aperture settings on your camera affect the depth of field within an image?

To make this process more meaningful, I am going to use an exercise on depth of field.I use this subject area only as an example.

You need to begin to think about setting up your own experiments so you can learn rapidly for yourself.

Experiment:
Understanding Depth of Field

In this series of experiments we have lined cards on the floor at equidistance apart (approximately 6 inches).

A tripod was used, so the camera would be secure in a set position. Focus was set on the red 5 of hearts for all of the images and a 50-200mm telephoto lens was used at a focal length of 72mm.

Experiment to see how different lenses record the same scene.

4 images: © 2013 Marla Meier. All rights reserved.


At f/22 – all cards are in focus.

Photo of playing cards lined up in a row to show an example of depth of field with an f/11 aperture setting by Marla Meier.
At f/11 – now the 4, 5, 6 are in focus.


At f/4.5 – now only the red 5 of hearts is in total focus.

 

1. Find a location to suit your experiment. A good location for learning about depth of field is a fence. Stand at an angle to the fence so you can use it as a distance marker.

2. Ask the questions . . . What am I trying to do? How can I do it?

A. How much of my photograph will be in focus when I use the aperture setting of f/4 and how much when I use f/16 or f/22?

B. Will the lens I use make any difference to what is in focus at f/4 or at f/16?

3. Select the lens you want to use. The first lens I will use will be a telephoto 300mm lens. Then I will use a “normal” (50mm) lens and my wide-angle (20mm) lens.

4. Put your camera on a tripod. My camera is on a tripod.

5. Begin the experiment. I select one spot on the fence and mark it with an object, such as a ribbon (maybe there is already a leaf on the fence or knot in the wood on which to focus).

I focus on that object, check my exposure using the largest opening (f/4) on the lens and I choose the shutter speed to get the proper exposure.

6. Take frame one. Take notes. I took frame one and I took notes. My notes contain information about what I was doing as well as what I was trying to do.

7. Change the settings, take a photograph and take notes. My next image, changing the f-stop and the shutter speed (to keep the exposure balanced) will be at f/5.6. Then I continue the experiment using f/8, f/11 and f/16. I will take notes.

8. Change lenses. I will change my lens from a telephoto (300mm) to a “normal” (50mm) lens to a wide-angle (20mm) lens and repeat the exercise as I use each lens I own.

9. Redo the experiment and take notes. I redo the experiment using all possible f-stops (and balancing the exposure) but not changing the focus or the distance to the ribbon/object.

10. Continue until you have finished the experiment. I continue the experiment using all of my lenses from wide-angle to telephoto.

11. Download your photos to the computer. If you like, transcribe your notes to the metadata of each photo within your post-processing program. You can also print out your photos and place them with your notes by creating a personal photography textbook.

12. Summarize what you have learned. I learned that the f-stop as well as the focal length of the lens affect depth of field.

I learned that when photographing with a large opening (f/4) the size of the area of what is in focus (the foreground to background width of the depth of field) is less than with a small opening (f/22).

Also, when using a telephoto lens, the effect of the change in f-stop is more noticeable than with a wide-angle lens. I will create my own personal photo textbook with this information and my photographs.

13. Repeat the procedure as often as necessary with any concept you are learning. This experiment wasn’t so difficult to do. I can do it with other concepts too. I just need to define the questions and to answer them by working the experiment systematically. I can do it!

Now that you have an example of a learning exercise, set up a format of your own that will help you do the exercises. Remember you will learn and remember more by defining, developing and working through the questions on your own. By setting up examples and coming to your own conclusions your personal notebook will become a source of information, reminders and more questions to be answered. It is an on going project.”

by Noella Ballenger
Updated: © 2015 Noella Ballenger. All rights reserved.

All written content (and most images) in these articles are copyrighted by the authors. Copyrighted material from Apogee Photo Mag should not be used elsewhere without seeking the authors permission.

1 Comment on Know Your Camera: Depth of Field Experiments

  1. Brilliant idea, I’ve been asked to do a presentation on explaining depth of field at our local photography club and if you don’t mind, I would like to use these ideas but I won’t use your pictures, I will do something similar.

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