Digital Tip: Exposure Part III — Aperture

Posted on February, 2015 by Mark Turner

Aperture, the size of the hole letting light through your lens, is the third variable you control to get properly exposed photos. Last October I discussed ISO, the sensitivity of your camera’s digital sensor. In November I wrote about shutter speed and how your choice is a creative one as well as an exposure control.

Family Portrait — Haddock family portrait, photographed at f/8

Like shutter speed, the aperture you choose affects the “look” of your photo as well as the exposure so it’s both a creative and technical choice. The family portrait above was made at a middle aperture to balance depth of field and shutter speed with proper exposure.

You can think of the aperture as the size of the “light pipe” carrying photons through your lens. The larger the diameter of the pipe, the more photons go through, just as a 2” water pipe carries more than a ½” pipe. Continue reading →

Digital Photo Tip: Exploring Pattern and Texture

Posted on January, 2015 by Mark Turner

A few days ago, during our recent cold snap, I stuck my Canon G12 compact camera in my pocket and headed out the door for a walk around our block. Where we live, that means walking at the side of the road for about a mile and a half. It was crisply cold and the late afternoon sun was low in the sky as I left the house.

I found several nice photo subjects along my route, but spent the most time lingering over a single frozen puddle, exploring the patterns and textures in the ice. It’s an intriguing and ephemeral subject, one temporarily frozen in time as well as temperature. I was reminded of the patterns in the sand from waves washing ashore, or the waves themselves when caught by an instantaneous exposure. There were figures, akin to the what you might see in the clouds while laying on your back on a warm summer day. And there was this luminous quality to the late afternoon light as it caught the ridges and textures in the ice. In short, I was entranced by this simple frozen tableau and lingered until the knees of my Carharts were soaking wet, my fingers frozen, and the sun had dipped too far below the horizon for a reasonable shutter speed. Continue reading →

Digital Tip: Exposure Part II — Shutter Speed

Posted on November, 2014 by Mark Turner

Children jumping, action frozen at 1/640 second

Last month I introduced the three things you can control on your camera that affect exposure: ISO, shutter speed, and aperture. I explained how changing the ISO setting changes the sensitivity of your camera’s sensor. If you missed it, or need a review, read about ISO here.

Shutter speed is this month’s topic. Choosing an appropriate shutter speed for your subject is a creative choice as well as being one of the variables that affect exposure. All cameras have a hole inside the lens that, when open, lets light hit the sensor (or film). The shutter controls how long the hole is open.

When the shutter is open for a very short time you are able to stop motion and freeze action. Conversely, a long exposure can blur a moving subject. If you’re hand-holding your camera you need to choose a shutter speed that is short enough to compensate for any movement of the camera in your hands. The longer the focal length of your lens the shorter the shutter speed needs to be to avoid camera shake.

Continue reading →

Digital Tip: Exposure Part I – ISO

Posted on October, 2014 by Mark Turner

When you go to the beach do you want a sunburn, a nice healthy tan, or a pale complexion? You’re in control by how much you expose your skin to the sun. If I spend too much time outside without my hat, my balding head gets burned. That’s analogous to an over-exposed photograph, although the results usually aren’t so painful.

Point Whitehorn Beach — Point Whitehorn beach, photographed on a sunny day at ISO 100.

This month and the next few I’m going to help you make sense of the three variables that interact to affect photographic exposure: the sensitivity of the digital sensor (or film), how long the light strikes the sensor, and how big is the hole the light passes through. We call those the ISO, shutter speed, and aperture. I’ll get to each of those and how they interact in this and the next few installments, along with exposure compensation.

You may wonder why this is important if you always use your camera in its fully automatic mode. In full auto, your camera is measuring the light and setting the ISO, shutter, and aperture to expose the subject correctly. Taking control yourself gives you creative options you don’t have in full auto mode.

Continue reading →

Digital Photo Tip: Improvised Rain Cover

Posted on September, 2014 by Mark Turner

Garden chairs on awet flagstone patio — Garden chairs on a wet flagstone patio, Pittsburgh, PA.

Last month when I was on a bus tour of Pittsburgh, Pennsylvania gardens with the Garden Writers Association I got caught out without my usual rain cover for my camera. We only had 20-30 minutes in each tour garden and I certainly wasn’t going to pass up the opportunity to photograph lush and beautiful gardens just because it was raining and I didn’t have proper protection for my camera. I really like the look of a garden in the rain. Continue reading →

Digital Photo Tip: Think Triangles

Posted on July, 2014 by Mark Turner

Triangular composition in group of Tulip Poplars — Strong triangular composition in group of Tulip Poplar trees.

There’s a lot of power in the humble triangle. Just as it brings strength to all kinds of mechanical structures, the triangle makes your photographs stronger, too.

It doesn’t matter whether you’re photographing your family, a sweeping landscape, something abstract, flowers, or anything else. Look for ways to incorporate one or more triangles into your composition. Continue reading →

Digital Photo Tip: Choose an Exposure Mode

Posted on May, 2014 by Mark Turner

Canon G12 exposure mode and ISO dials — Exposure mode and ISO dials on the Canon G12 compact camera

Most digital cameras, except for the very simplest, offer several exposure modes . How do you choose which one to use? It depends on what’s most important in the photo you’re making. This month I’ll explain the difference between the primary modes: Program Automatic, Aperture priority, Shutter priority, and Manual. Your camera may also have a variety of Scene modes. Continue reading →

Digital Tip: Polarizing Filter

Posted on April, 2014 by Mark Turner

With the advent of digital photography we have so much post-processing control in applications like Adobe Lightroom, Photoshop, or Photoshop Elements that many of the filters we once used are no longer needed. But there are two exceptions, filters that I still carry and use in my outdoor photography. This month I’ll remind you why a polarizing filter is still important.

Most people, when they think of a polarizing filter, associate it with darkening a blue sky. That’s certainly one of the most common uses of this filter. You can compare the effect of the polarizer in this photograph of our home made on a sunny afternoon with the sun roughly 90° to the left of my camera. Without the polarizer the grass is lighter green, the sky is a pale blue, and the brightness values of the yellow paint, the grass, and the sky are similar. Continue reading →

Digital Tip: Photographing Christmas Lights

Posted on December, 2013 by Mark Turner

Holiday lights on outdoor Christmas tree

This holiday season you can’t avoid coming across wonderful light displays that add a festive touch to our long nights. Whether it’s the lights on your own home, a favorite neighborhood you like to visit, or one of the great public garden holiday light displays, you can make great photographs of the lights. Just don’t expect to get top results with your phone camera (although it doesn’t cost you anything to experiment). Continue reading →

Digital Photo Tip: Window Light Portrait

Posted on October, 2013 by Mark Turner

One of the things that sets professional photographers apart from snapshooters is that we’re always looking for the light, seeing how it plays across our subject. Modern cameras are very good at getting an acceptable exposure in almost any light, but we’ve all seen thousands of photos taken in very bad light. You can do better. Here’s one approach.

Natalie and I were visiting her mother, Betty, not too long ago. She lives just a mile from us so we’re there often. Her home has a wonderful sun room, with windows all along the south wall and a couple of skylights so the room is bathed in light. Betty spends a lot of time sitting by the window where she can watch the birds in her garden or reach a book on the shelves beside her chair. Continue reading →