Macro & Close-ups

Macro photography and depth of field

Written by Bernard Dery

When taking macro shots, details are achieved by focusing accurately and making sure enough of the subject is in focus.

A common comment about macro photography is that you’re more likely to work at an aperture of f8 than f2.8. In other words, when working at very close distances, the depth of field can get really small and it is sometimes required to close the aperture to increase the DOF.

Not all rules must be followed however, especially in photography.

What is really the outcome of playing with the aperture when doing close-ups? What effects can be achieved with a shallow or deep DOF? This short article aims at giving examples of the trade-offs of using wide or small apertures when doing macro photography.

Two goals for taking macro shots

Two goals are usually aimed for when shooting macro: subject details and subject isolation. Details are achieved by focusing accurately and making sure enough of the subject is in focus. Subject isolation is achieved by making sure the background is blurred and the bokeh smooth.

Effects of varying aperture settings

The four pictures presented below were shot with the same lens (a dedicated macro lens), with the camera placed on a tripod. Only the aperture (and thus the exposure time) was varied, going from wide (f2,8) to moderately small (f7,1).

The first picture, at f2,8, shows an extremely smooth background. There is no doubt here that subject isolation is effective. The background is completely blurred. However, only a small portion of the budding flower is in focus. What’s more, the actual focus point does not seem to be at the very tip of the flower, but a little behind it. Part of the bud at the bottom left is also in focus, as an afterthought. The result is that the eyes fail to find an anchor point.

The image at f7,1 is opposite. The whole subject is sharp and detailed. However, the background is busier, with visible patterns that can distract the viewer.

The image at f5,6 shows the same distracting background, to a lesser extent. The result is a more pleasing, more balanced image.

The picture at f4 shows both a very effective subject isolation, and satisfying details. The background is almost free of patterns and lines which would distract the viewer, but the level of details on the flower is high enough to provide an anchor. The whole tip off the flower is sharp, and the stem transitions smoothly into an out-of-focus blur. It is probably the most balanced picture of the four.

No set rule for macro photography

These four examples illustrate that there is no firmly set rule for macro photography (and for photography in general)! The photographer should always adapt the camera settings to the scene in front of him. With digital, it is easy to experiment and explore many possibilities.

Smooth background; small portion of flower in focus.

Subject sharp and detailed; busy background.

Some distracting background but more balanced image.

Effective subject isolation, and satisfying details.


Photos by Bernard Dery.

About the author

Bernard Dery

Bernard was born and still lives in Quebec City, Canada. A doctorate candidate in Physics, Bernard works full-time as an optical designer at EXFO, a world leader in telecom tests and measurements tools. His professional interests go from fiber optics to atmospheric data collection and lasers.

His first contact with photography was a Vivitar fixed lens camera that he had purchased at age eight. His interest developed slowly, and for many years Bernard limited himself to family and travel pictures.

Bernard discovered the world of digital photography in February 2004, when he purchased his first digital camera. Developing an interest for composition, he experimented with many subjects: landscapes, nature, cities and architecture.

Bernard
soon began to invest more time and energy into his new found hobby, finding new and beautiful subjects to capture everyday. His challenge is to capture the mood and emotion carried by a scene as it presents itself to him.

A trip to Italy in
September 2004 fueled his growing interest with numerous magical photography opportunities.

Bernard and his wife like to spend free time near a lake at his family's summer house, where he finds new subjects to capture every day. His interests are varied and include hiking, camping, swimming, boating and reading, as well as most winter
sports.

Bernard, known as bdery on forums, uses a Pentax K20D and W80, Canon S2 and a Nikon SQ as a backup.

Thumbnails are of photos by Bernard Dery - used with permission
Copyright Bernard Dery All rights reserved

4 Comments

  • June, like any photographic technique it’s going to take some practice to learn how to get the depth-of-field you desire in a photo. While DOF is primarily controlled by aperture size, other factors also come into play such as the focal length of the lens and the distance the lens is from the subject.

    While you need a wide aperture to decrease DOF, you don’t always have to use the widest.

    Your camera may also have a Depth-of-field Preview button, a button on the camera body located near the lens barrel. When you press it, you can check the range of acceptable focus through the viewfinder and they adjust the aperture as needed. Check your camera manual for specifics.

    Also, many photographers use a tripod when taking macro shots to help keep the camera steady and to more easily watch the effect of settings changes through the viewfinder.

  • I bought a dedicated macro lens about a week ago and was so eager to try it right away by taking photos of really tiny flowers. I was aware of what wide aperture will do to a subject in a photo, that is sharp in-focus subject and blurred background (in your term, subject isolation) and i was on a mission to use just that when i went to our local botanical garden.

    I was so disappointed with the outcome when  the picture came out both sharp and soft/blurred on some parts of the same flower!  i thought the lens had some defect!!

    Well, this article shed light to that soft blurring issue.  I never thought that macro lenses have really small DOF.  When i looked at the “DOF chart” that came with the lens,  it turned out that the DOF may be as shallow as 4mm wide!!  So taking photos of a flower that is about  half inch tall, you may get a sharp image of the tips of the flower but the bottom part  will be blurred.
    Keep posting some tips about macro photography….i am learning a lot!  Thanks.