Tag Archives: optics

Altering reality in wide angle

Wide-angle lenses are lenses that, as the name suggests, capture a wide angle of view. They’re great for fitting a wide scene into a single shot. A wide-angle lens can catch a long parade marching down the street, spreading to left and right; it can catch a massive sprawling mountain range.

Wide-angle lenses can be tricky, too. Humans don’t see in wide angle, so these images are distorted and unnatural to our eyes. Sometimes, that’s a feature.


Wide Angle to make something feel large

Large things loom. Whether that large object is your parents when you’re a child, a huge skyscraper, or a thunder cloud, big objects have a sense of hanging over you. Wide-angle lenses can capture that sense, even for modestly-sized objects.

Below is a shrine at the Albuquerque Botanical Garden Japanese Garden. It’s maybe 15 feet wide and 15 feet high. But with the help of wide angle, it can fill a whole frame. The top frame is as a 16mm wide-angle lens captures the shot. All the lines that should be straight are curved, because this lens is a type of wide-angle lens called a “fisheye”. This could be the desired effect, or you can correct the curvature, as in the second picture. This time, I was pursuing the second image. Sometimes, the other is the goal. That’s one cool thing about digital photography–both are available in any given image.

The shrine at the Japanese Garden

Shrine at the ABQ Biopark Japanese Garden, with fisheye distortion uncorrected.

The shrine at the Japanese Garden

With corrected perspective.


Wide Angle to capture a wide scene

This one’s obvious, but still awesome. Some images need a lot of space. Sometimes, you can get a wide-angle image by stitching several traditional images together. But as in the top image, only a single capture can catch the ducks taking flight.

In the bottom image, the angular distortion from the fisheye lens is fine uncorrected, because there are no straight lines on that rock to betray the distortion. And the wide angle here allowed me to get the sun in the frame. The distortion to the sun here is called a “sunstar.” You can get them by shooting with small apertures, which leads to light diffraction. Here’s a nice brief article if you want to learn more about sunstars.

ABQ Biopark Japanese Garden wide angle, ducks taking flight

The pond at the Japanese Garden

Bisti Badlands and Sun Star

A rock formation at Bisti Badlands


Wide Angle for composition

Wide-angle lenses give a photographer different options in guiding the viewer’s eye in a photograph. You may have heard that long lenses compress depth, thus why they are pleasing for portraits. Wide lenses exaggerate depth. The righthand side-view mirror on cars is slightly wide-angle. This is why “objects may be closer than they appear.” Your side-view mirror has exaggerated the sense of depth.

Additionally, wide-angle lenses can focus on nearby objects. My 85mm lens has a minimum focal distance of 1 meter. My 70-200 varies from 1 meter to 1.5 meters. My fisheye can focus nearly up to the point I bump into the subject.

Both of these factors give the photographer different creative freedoms when composing with a wide-angle lens.

In the first image, I found this hanging rock fascinating. I put my lens right next to this rock when I shot, but because of the exaggerated depth, it doesn’t feel as claustrophobic as the shot was. The rocks in the background are only a few feet away, but they feel more distance. Here, I also employ the wide angle to make the rock loom large. That hanging arm was no more than 3 feet long.

In the second image, the ability to get close to the statue in the foreground meant I could fill more of the frame with it. And I can fit the building comfortably in the background. So I can make a relatively small object the same size in the capture as a large object.

Rock formations in the Bisti Badlands

Rocks and sun at Bisti Badlands

160217-UNM-campus-4711

University of New Mexico campus, and statue of school mascot, the Lobo

 

Did I miss anything? I love a good photo discussion, so let me know!

World Pinhole Photography Day

Did you know that a pinhole can focus and project light? A pinhole in an opaque material is the world’s simplest camera! Yesterday was World Pinhole Photography Day.

History

The discovery of pinhole optics massively predates photography (the act of chemically recording a projected image). During the Renaissance, painters traced scenes projected onto a canvas by a pinhole on the opposite wall. The use of a pinhole to project images goes back to 5th century BC China.

A camera obscura uses a pinhole to project an image. Renaissance painters could then trace these images. (image source: Wikipedia)

Why Pinholes?

In an age of digital cameras and high-end optics, the pinhole endures, charming and simple.  In honor of World Pinhole Photography Day, I went on a pinhole outing.

You might ask, what is the point of pinhole photography in this day and age? There are aesthetic and practical reasons. I like knowing exactly how my lens works, for once. Even a prime lens can have upwards of a dozen pieces of glass in it. I have a good science background, and I can’t even touch that level of optics. A hole in black plastic. I get that. Pinholes have interesting properties. True, they don’t focus nearly as sharply as lenses. But because pinholes have such small apertures, they have nearly infinite focal depth.

Brief photography lesson: larger openings (apertures) allow more light and create shallow ranges of focus. This can be desirable in a portrait. Small openings permit less light and increase range of focus. This might be preferable for a landscape. Sufficiently small openings cause softening due to diffraction (physics of light stuff). If you shoot on an SLR, you may have noticed diffraction-caused softening on shots at f/22. The pinhole I use is f/177. This diffraction is what gives pinhole photos their texture.

The upshot: pinhole photos flatten a scene. Something a yard away will look similar to something 100 yards away. This allows a photographer to create interactions between different depths that wouldn’t be possible with a conventional lens. And finally, pinholes can create a really fun old-timey effect.

My setup

My setup is a bit like sticking a horse-drawn carriage on a rocket ship. I use a Lensbaby composer with the pinhole optics kit. My camera is a Sony Alpha 7s. Pinhole photography, due to the tiny amount of light transmitted, has slow exposure time. Exposures are often measured in multiple seconds. The Sony Alpha 7s is one of the fastest consumer cameras in the industry, with a maximum ISO of 409600. Thus, I was able to take decent handheld pinhole images even in low light by using high ISO.

Lenbaby pinhole on Sony Alpha 7s.

Lensbaby pinhole on Sony Alpha 7s.

The Images!

ISO 409,600, 1/6 second exposure. No tripod. Indoor shot on a rainy day.

ISO 409,600, 1/6 second exposure. No tripod. Indoor shot on a rainy day.

ISO 20,000; 1/60 sec.

ISO 20,000; 1/60 sec.

ISO 80,000; 1/60 sec.

ISO 80,000; 1/60 sec.

ISO 12,800; 1/60 sec.

ISO 12,800; 1/60 sec.

ISO 16,000, 1/60 second exposure.

ISO 16,000, 1/60 second exposure.

ISO 160,000, 1/10 second exposure. Indoor shot on a rainy day.

ISO 160,000, 1/10 second exposure. Indoor shot on a rainy day. I love how it looks like a 40s cheesecake shot.