Zone of focus, depth of field, and what you set your sights on.

Choices and the focus of your attention.

Viewfinder Vol 1, Issue 9See all issuesSubscribe to Viewfinder

A special warm WELCOME to new subscribers: Jason, Mark, Neil (who writes Photos, Mostly), and Orelad. And a huge THANK YOU to all subscribers, old and new, for reading and being a part of this community.


In this issue:

  • Results of last week’s poll: how much Viewfinder?
  • Zone of focus
  • Nikon Small World Photomicrography Awards
  • Astronomy Photographer of the Year 2023
  • Last call for impermanence photos
  • Project prompt: Very large, very close, very small
  • Status: Dec 10-16, 2023

“How much Viewfinder do you want?” poll: inconclusive

A bar graph visualization of the poll results. "Slow it down - 1 / wk." received 43% of votes, "Keep it the same - 2 / wk." also received 43%. "Whatever - no preference" received 14% and "I challenge you to write more" received 0%.

Thank you to everyone who voted–I really appreciate it! Results were split between “Slow it down to once a week” and “Keep sending twice a week”. No one voted for “I hereby challenge you to write as much as humanly possible”; I am grateful this was not the winning response.

So, I’ve decided to sort of split the difference: some weeks you’ll get one issue; in others, two. This offers some flexibility around holidays as well. And if I just can’t help myself and need to write, I can also publish directly on this website; when I do, I’ll let you know.


Zone of focus, depth of field, and focus of your attention

In photography, “zone of focus” is the term for the area of the scene that is rendered “sharp” by the lens. It’s the area in front of, and behind, the thing you’re focusing on (called the “focal plane” or “focus point”). Zone of focus is often used interchangeably (and inaccurately) with the term “depth of field”. [Technically, depth of field delineates the zone of focus. Said another way, zone of focus is the depth of field that spans the focus point.]

End zone of focus

My apologies in advance for the football imagery.

Black and white illustration showing how zone of focus works.
Zone of focus.

Imagine you’re standing in the end zone under one of the goal posts, with your camera pointing downfield. Players are scattered up-and-down the field. You focus on a player standing on the 50 yard line and press the shutter button. In your picture, players on the 40 and opposite 40 yard lines were also in focus, but not those players closer or past the 40 yard lines. Your zone of focus is 20 yards wide.

When an image has a very wide zone of focus, objects both near and far away can have crisp definition. Imagine every player on the field, regardless of position, completely sharp. Or, if the zone of focus is narrow, perhaps only a single player is sharp while the rest of the scene is a hazy blur (this is unsurprisingly called “focus blur”).

Choosing what to focus on, and which parts of the scene to include in the zone of focus, and which to allow to be out of focus, is one of the most important considerations in photography.

Close-up color photograph of a lens, showing the blades of the aperture.
Aperture in a lens. Photo by Pixabay.

Aperture and depth of field

Depth of field, which determines the width of the zone of focus, is controlled by the aperture in the lens. The aperture is an iris, like that of the human eye, that can open or close to allow more or less light into the camera. The aperture can be adjusted from “wide open” (e.g. let in everything the lens can collect) to (depending on the lens) a tiny opening the width of a toothpick.

When the aperture is wide open, lots of light is let in. This can be useful for dark scenes, like indoors or at night. The human eye’s iris dilates in the dark for this exact purpose. Yet, due to the nature of optics, when the aperture is set wide, the resulting image has a very shallow depth of field. Conversely, when the aperture is closed down, less light passes through and the image will have a wider depth of field. Obviously, it will also be darker.

So, large aperture = lots of light, shallow depth-of-field. Small aperture = less light, wider depth of field.

Photography requires you to make decisions about how you balance these (and many other) characteristics when making a photograph. Sometimes you want to have everything sharp, or maybe the scene is very bright, so you close down the aperture and limit the amount of light. Or maybe it’s dark and you need more light, or you want a shallow depth of field, so you open the aperture. Or something in the middle. Choices. 

Focusing your attention

You can probably see where we’re going with this.

Just like when making a single photograph, you make similar choices for your art making practice as a whole. These choices are informed by the situation you find yourself in. There’s no right or wrong, just what you need at that time.

If you open yourself up, try to do it all and let everything in, you’ll amass a lot of “raw materials” to work with… ideas and inspirations and curiosities galore. You’ll also create little focus. This is best when you’re starting something new, or when you feel like you’re (artistically) in the dark. This can be called “exploration”, “workshopping”, “studies”, “experiments”, or “exercises”, but also “reading”, “visiting museums”, and “talking with other artists”.

If you narrow your attention, you get more clarity about your work. This is ideal when your project is well underway. The overall volume of the “raw materials” available to you declines, but you’re more focused and need them less at this stage. You’re working toward a specific outcome. It’s less about discovering the work and more about doing the work.

You’ll move between these states many times in your art making practice. And, like a lens, you’re never fully one way or the other. Some light has to be let in–part of you will always be open. Likewise, you’ll always have some amount of focus. It’s all about matching choices to the needs of your art making.

What is the zone of focus for your current work?


Nikon Small World Photomicrography Awards

Color photograph of an extreme close-up of a butterfly wing.
Charaxes sp. (emperor butterfly) wing, ©2018 Charles B. Krebs

It’s a characteristic of optics that, as you move closer to a subject, the zone of focus narrows as well. Depending on settings, when you point your camera at an object 3’ away, things might start looking completely sharp at 2.5’ and then get blurry beyond 3.5’. However, focus on something 10’ away, and the zone of focus might widen to 7’ -> 15’.

Now imagine focusing on something so close and small that it’s imperceptible to the human eye. The depth of field is measured in fractions of an inch. Imagine the challenge of getting it perfectly in focus, and for extra difficulty points, choose a subject that’s alive and moving. Framing your picture might require moving the lens a distance equal to the width of a human hair.

Welcome to photography with microscopes, the subject of Nikon’s perennial photography contest. Every year, Nikon shares some of the best images made under these challenging conditions. When you think of the technical mastery required, some of these images are… just astounding.

Small World Photomicrography Awards [Nikon]


Astronomy Photography of the Year 2023

Color photograph of two galaxies.
Andromeda, Unexpected © Marcel Drechsler, Xavier Strottner and Yann Sainty

Now taking photographic possibility to the opposite extreme… glittering stars, shimmering galaxies, fiery suns, and silver moons. Consider that astronomy photographers not only capture things beyond the range of human perception, but many images are collected light that first started its journey to earth before man. Even a photograph of nearby Venus is made from light that first traveled from the Sun, reflected off the planet, and then found its way to Earth and into the photographer’s camera. 

‘Astronomy Photography of the Year’ is an annual competition put on by the Royal Museums Greenwich, showcasing “the world’s greatest space photography”. Categories include: Galaxies, Aurorae, Our Moon, Our Sun (my favorite image of the bunch), People and Space, Planets, Comets and Asteroids, Skyscapes, Stars and Nebulae, and more.

Astronomy Photography of the Year [Royal Museums Greenwich]


Text: "Impermanence"

Last call for impermanence images

So far, one Viewfinder subscriber was inspired by last week’s prompt and sent along an image they made. I’d love to showcase your work alongside this one in the next issue of Viewfinder; sketches and works-in-progress are welcome.

Care to share yours? Email it to ron@startphoto.com


👋 Project prompt: Very large, very close, very small

Your prompt this week is: to depict something very small as large, something very far away as nearby, or something very large as small. As usual, art in any medium is welcome.

The goal here is to think about how our choices about framing, positioning, perspective, scale, and other formal aspects of design transform how the scene is depicted in our image.

When you’re done, if you’d like, email an image of your art to share with this community. I’ll include a few of them in a future issue of Viewfinder.


Status update: Dec 10 – 16, 2023

Art making:

✅ Photographed 7 out of 7 days this week. Perfecto!

Favorite photo made the week:

Black and white photograph of an outdoor Christmas ornament.
12-15-2023-9 (Christmas ornament)

How is Viewfinder (and StartPhoto) doing?

  • Gained 4 new subscribers
  • Published 2 articles
  • StartPhoto.com: 19 site visitors

Sharing is caring

One of the best ways to support this project is by sharing:

  • Share Viewfinder with a friend, invite them to subscribe.
  • Leave a comment, ask a question, share your thoughts.
  • Like button… easier than leaving a comment. 🙂
  • Share details about your projects. This supportive community would love to hear about what you’re working on, what you’re thinking about, what you plan to do next. Send an email: ron@startphoto.com.

Your pal,


Cover image: 03-05-2013 (Curve). ©2013 Ron Johnson. This image demonstrates a shallow depth-of-field / narrow zone of focus.