All posts by G Dan Mitchell

G Dan Mitchell, photographer and visual opportunist focusing on the Pacific coast, the Sierra Nevada, redwood forests, California oak/grasslands, California deserts, urban landscapes, night photography and more. Posting daily photographs since 2005, along with articles, reviews, news, and ideas.

Reader Questions, Technique

Reader Question: About Depth of Field

February 16, 2015 G Dan Mitchell Leave a comment

I recently received an email from David, who has some questions about depth of field:

As you have a lot of experience of using the Fuji X-E1, may I please ask you for some advice regarding landscape focusing.

My aim is to use the 18-55mm kit lens with the majority of shots taken at the widest end. I have in mind setting the lens at Hyperfocal distances, based on a crop factor of 1.5 and a circle of confusion of 0.02. I think the first figure is reliable, but I’m not sure about the second in relation to the X-E1 – perhaps you could confirm.

I have already done some testing at home using the attached table (which come from the well respected DOFmaster site).

In my experiment I carefully measured distances at apertures of f8 and f11 using a tripod and a printed card as the subject. I set the lens manually at the hyperfocal distance, using the EVF distance scale. I was disappointed to find that the closest point of focus was not as sharp as I had hoped. Have you any idea why this may be?

I did a further test on aperture f11 and this time set the distance scale at 4 feet (2/3 of the way between 3 and 5 feet). This resulted in a sharp image from 3.5 feet. This would suggest that the distance scale is not accurate.

Any suggestions you have to overcome the problem would be much appreciated.

Let me preface my response on the depth of field (DOF) issue by congratulating you for taking the time to conduct your own experiments. One of the great things about digital cameras is that we don’t have to trust what we read — we can easily and quickly conduct the experiments ourselves. In addition to getting the answer to the question at hand, we end up knowing our gear at a much deeper and even intuitive level, which is extremely important when we are in the field and we don’t have time to ponder and calculate, but must instead make a photograph in the moment.

The rest of this post is going to be somewhat involved, so let me share a quick thought right at the beginning:

The usefulness of DOF calculators is very limited, as they are based on subjective assumptions that may not match what you are doing with your photographs. The best way to align your expectations with exposure choices is to test them yourself and evaluate images in the form that you most often produce — and not just at 100% magnification on a computer screen.

What is DOF? Essentially the depth of field is the distance range in front of and behind (unless you focus at infinity) the focus point within which subjects are likely to sharp enough to seem in focus when the photograph is viewed at some arbitrary magnification. This size of this range increases as we stop down (for example, going from f/2.8 to f/8 expands the DOF) and decreases as we open the aperture (going from f/8 to f/2.8 contracts DOF). This is a source of creative control for the photographer. A smaller aperture can allow subjects across a greater distance range to appear relatively sharp, while a larger aperture can keep the primary subject in focus while pleasingly “un-focusing” elements in front of and behind the primary focus point. Continue reading Reader Question: About Depth of Field →

Photographs: Nature, Photographs: Northern California, Photographs: Sierra Nevada, Photographs: Yosemite

Afternoon Light, Forest and Cliff

February 16, 2015 G Dan Mitchell Leave a comment

Yosemite Valley forest and cliffs in hazy late afternoon light

This past weekend I had time to visit Yosemite Valley for a couple of hours. That doesn’t sound like much time, but it is enough to see a few things and make a few photographs. (We would have had more time, but we were distracted by migratory birds as we crossed the Central Valley, and by the time we arrived in the park it was mid afternoon.) Coming into the Valley we spotted the first evidence of the annual migration of the Horsetail Fall photographers, lined up in a spot along the Merced River a few hours before sunset. (We saw more of them on the way out of the Valley later in the evening.)

For me, photography in the Valley is often about the light, with the quality of the atmosphere being close to the light in importance. Given that there were no clouds I was not too optimistic about the prospects, but when we arrived at a meadow late in the afternoon I saw some beautiful haze that was starting to be backlit by the lowering sun. I found some trees — the group in this photograph and others in a pair of photographs I’ll share later — and I looked for a composition that eliminated the bright sky, that put the sun close to directly behind the trees, and which put some of the valley walls and towers in the frame in order to provide some form and textural relief to the haze. Then it was a matter of lining up the elements of the photograph so that the tallest trees were within the outline of a large tower. Shooting almost straight into the sun (and engaging in interesting gymnastics in order to shield the front element of my lens from flare-producing direct light), I made a few exposures.

Text, photographs, and other media are © Copyright G Dan Mitchell (or others when indicated) and are not in the public domain and may not be used on websites, blogs, or in other media without advance permission from G Dan Mitchell.

Photographs: Central California, Photographs: Nature, Photographs: Northern California, Photographs: Wildlife

Two White-Faced Ibises

February 15, 2015 G Dan Mitchell Leave a comment

Two white-faced ibises look at one another, San Joaquin Valley wetlands

When I spot the white-faced ibises down near or in the water, most of the time they do not seem to be interacting very much with one another. In fact, I most often find them feeding alone, or if others are around they are at a distance. (I have seen groups in flight, and I feel that I tend to see them group together a bit more later in the season.)

I was a little surprised to see this pair together. Over a period of a few minutes they danced around one another, adopting a series of mirrored poses, and here they momentarily stood and turned towards one another before resuming the dance and then soon flying away.

Photographs: Central California, Photographs: Nature, Photographs: Northern California, Photographs: Wildlife

White-Faced Ibis

February 14, 2015 G Dan Mitchell Leave a comment

A white-faced ibis feeds in a San Joaquin Valley winter pond

A few years ago I knew almost nothing about the migratory birds of California’s Central Valley. The first time I photographed them I was simply amazed by their sheer number and the variety of shapes, behaviors, and calls — but I could barely tell one from another. Birds flew over and I photographed them, often not knowing what I was capturing with my camera.

Sometimes, when I looked at the photographs later, I would discover some interesting feature of the birds that I hadn’t paid attention to or couldn’t see at the time. I realized later than my first encounter with the ibis was such a photograph – I had photographed a line of birds overhead, their shapes silhouetted against the sky, and when I looked at the photograph closely I was surprised to find the characteristic long, curved beaks. I was fascinated by the shapes, but I had no idea what they were. Obviously, they were white-faced ibises, like the bird in this photograph. The ibis seems perfectly adapted to hunting in the shallow waters of these wetlands, with their long legs and long, curved beaks. If you look closely you may be able to tell that this one has just picked up something from the water in its beak. The feathers of the ibis are a marvel. At first the bird can look dull and almost black, but put it in the right light and the back feathers turn out to contain a huge variety of colors, from pinks to yellows to greens an browns and black.

G Dan Mitchell Photography

All posts by G Dan Mitchell

Reader Question: About Depth of Field

Afternoon Light, Forest and Cliff

Two White-Faced Ibises

White-Faced Ibis

Photographer and visual opportunist. Daily photos since 2005, plus articles, reviews, news, and ideas.