So I was wondering which picture I should blog about next: since my lovely wife posted this as her profile picture, I decided this would be the one! Katie is currently an optometrist in the Frisco, Texas area (which is north of Dallas). This photo was taken in April, 2014, at the University of Houston College of Optometry, shortly before her graduation.
My goal was to take an environmental portrait: to show her in an exam room, where she examines patients' eyes. I wanted to show the room, and any instruments that an optometrist would use. I scouted the exam room prior to setting up and I looked for the best way to achieve those goals. My next task was to figure out the best way to illuminate her and the room. I wanted to make sure I did this before Katie arrived. It's important to scout and test a location before the subject of an environmental portrait arrives, because they may be short on time.
I planned to use a flash attached to the top of the camera to illuminate Katie. I quickly identified and decided to use an instrument commonly used in optometry called a phoropter, with the idea that Katie would stand next to it. I took some practice photos to figure out which settings for the flash would work the best. I had the flash pointed at the ceiling, and a dome-shaped diffuser on top of it. I rarely use direct flash: it washes out skin tones too much, and causes too much glare. It also casts harsh shadows. Pointing the flash upwards, along with using the diffuser, would help the light bounce off the walls and low ceiling and soften the light on her skin and the phoropter. I would have preferred to use a couple of studio lights with larger diffusers on them to help illuminate her face even better (create a more 3-dimensional look), but there wasn't enough space for that. I was backed up against the wall for this photo!
Sometimes, I like to throw the background way out of focus so as to draw more attention to the main subject. Since this was an environmental portrait, I wanted to keep the background slightly in focus-- enough to show the details of the exam room, but not so much in focus that it was a distraction to the main subject. I chose an aperture on my camera that was appropriate for this. This caused a small problem that, fortunately, I was prepared to handle.
First, I needed to have the shutter speed on the camera on a fast enough setting that I could hold the camera in my hand while taking the picture (the space was too tight to use a tripod effectively). I also wanted to use a relatively low ISO setting on my camera. The ISO setting on a camera is one of the ways that the camera lets in light: higher ISO settings let in more light, but the image is noticeably more grainy (called "noise" with digital cameras). An on-camera flash can only illuminate out to a certain distance, especially considering that the power of the light falls very rapidly with distance. (see: http://petapixel.com/2014/07/01/inverse-square-law-light-explained-simple-terms-photographers/ ) If I used a fairly low ISO setting, a shutter speed that would minimize camera shake, and an aperture that would keep the background only slightly out of focus, then the background would have gone dark-- since the flash would not have illuminated the back of the room, and the camera itself would not have let in enough light with those settings. I could have used a higher ISO setting to bring out the background more, but that would have made the image much too grainy. I could have chosen an aperture on my camera to throw the background more out of focus. This would have let more light into the camera, and the background would have shown up better. However, as mentioned, I did not want the background too much out of focus.
The solution? Illuminate the room behind Katie with a studio light with an umbrella attached. The light would illuminate the room, while the umbrella would soften the light and make the illumination more even. (The flash would trigger a sensor on the light, causing it to flash). I took some test pictures to figure out how bright I needed the flash from the studio light to be.
I had my solution. I would illuminate Katie and the phoropter with my flash, and illuminate the rest of the room with the studio light and umbrella. This would allow me to achieve good illumination on Katie's face, have the background only slightly out of focus, and allow me to use an ISO setting on the camera that would not cause too much digital noise. I did some final test photos to see which settings on the camera, flash and studio light would work the best. Note that I did all of this before Katie arrived!
When Katie arrived, I led her into the room. Since I had prepared my lighting in advance, the only thing to do with her was to take several photographs using different facial expressions and angles on her face and body.
I did take some extra photographs using other instruments used by optometrists (and I had planned and did lighting tests for each while Katie was out of the room) but this one was the best of the photo session. I edited it for brightness, contrast and color balance. I took out some of the digital noise (there wasn't much to remove since I had used a fairly low ISO setting).
Many thanks to my wife, Katie, for being patient with me as I tested my lights and posed her at different angles to achieve the best picture of her.