Monday, March 19, 2012
Anatomy Of An Architectural Photo Shoot—03/19/12
Every important step in the making of an architectural exterior
|This Article Features Photo Zoom|
WORKING THE LIGHT
When you're shooting an exterior, your first task is to determine at what angle you'd like to shoot the structure, followed by the time of day the light will be ideal for that vantage point. A good rule of thumb is that if your view faces east, you'll want to photograph the building in the evening when the setting sun will bathe the façade in a warm glow. Facing west you'll want an early morning shoot when the sunrise provides the illumination. That's not what I did, though, because I wasn't so concerned with the light falling on the building itself: I knew it would be illuminated from within, and would “glow” all on its own. So I chose to make my west-facing shot after sunset, when the sky was a deep, shimmering blue.
The actual shooting time is fairly intense, because you might find yourself bracketing exposures. Normally if you're shooting RAW and simply watching as the light changes and dims, you don't need to bracket too much. But I wanted to ensure I had the ideal depth of field (I didn't want to turn pinpoint light sources into stars, which happens above f/16) along with the perfect illumination of the subject and in the sky. Mostly, though, I was working to refine my shutter speed so that cars driving by would create interesting foreground light streaks. The shutter speed isn't normally much of a concern when it comes to architecture, because the camera's locked onto a tripod and the building just isn't moving. (If it is, you've got much bigger problems.)
One of the biggest concerns when photographing architecture is that, unlike many typical subjects, perspective distortion is a real distraction. The ideal way to photograph a tall building is to choose a vantage point approximately one-third of the way up the building (like the 10th floor when photographing a 30-story structure). That usually means in or on an adjacent building, but in this case I was denied access to every building that would offer a useful vantage point. That meant I was forced to shoot from the ground.
I could stand directly across the street from my subject and point my camera up at a 20-story building with an ultrawide lens, but that would create all sorts of awful distortions from the wide-angle up-close perspective. So I was left with a third choice—shooting from part way the block. The building I was shooting sat on top of a hill, though, and the middle of the block was in a bit of a valley. So I resorted to option four, and had to position myself a full block away at the top of a gentle rise that got me back to ground level with the subject. I knew I'd still be pointing my camera up a bit so I rented a 90-mm tilt/shift lens to help control the perspective in the camera. (Wide-angle perspective correcting lenses are immensely useful for architecture; I usually use a 17- and a 24-mm t/s lens when photographing architectural interiors.) Unfortunately that was a bit too long for even my distant position. So I was forced to shoot with my normal 50mm lens.
The more you tilt the camera vertically, the worse the keystoning effect becomes. (Keystoning is the illusion that parallel lines appear to converge.) The ideal way to fight this in camera is to keep the camera as close to level as possible, which will keep the sensor plane parallel to the building's plane. So I composed with the building positioned significantly toward the top of the frame and cropped the wasted foreground space accordingly. Still, though, there was a tiny bit of distortion.
If this distortion is enough to bother you you'll want to open Photoshop and use the Lens Correction tool to adjust the vertical perspective to help straighten up the lines on the building. If you're prudent with where you position your camera, where you point it, and where you place the subject within the frame, you should be able to keep this post-production correction to a minimum—which is just how I like it.
With the right light and the right perspective, it's time to make the finished product look its best. That usually means contrast, brightness, sharpness and saturation, but in this case it also meant filling in the dark windows to make them appear lit. I had planned ahead with my client, who thankfully sent out a memo to the tenants asking them to leave their lights on for my evening shoot. Still, no matter how much you prepare there are going to be some dark windows. In this case there were quite a few. A friendly security guard went around turning on lights as I watched from my perch a block away and guided him by cell phone, but still the façade had significant portions unlit, and I was running out of time. So I shot knowing I would fix this problem in post. I relied on a simple perspective cloning technique found within the Vanishing Point tool in order to copy lit windows in place of dark ones. First an aesthetic decision: should I light up literally all the windows? I decided no, as this would look more unreal than a “mostly” lit building. That, of course, is simply a matter of personal preference. So I cloned in windows until it felt right. The approach is easy enough even without the Vanishing Point assistance: you choose a lit window near a darkened one and use it as the source for a clone stamp. But if you want to work with windows that are far apart—which is a great way to hide the fact that you're duplicating a window—the perspective correction of the Vanishing Point filter is essential.
You first use the “create plane” tool by clicking on four corners of a rectangle within the frame—such as the building itself. Then you can drag the grid until it covers the entire area on which you'd like to work. Next, select the stamp tool (still within Vanishing Point) and alt-click to set a starting point before clicking on the area you'd like to paint. The Vanishing Point filter does all the hard work of adjusting the clone stamp to correct its size and perspective. It's an amazing bit of post-production wizardry that's actually pretty darn simple for the photographer. And in the end, that's a good analogy for everything I did in this shot—a lot of simple techniques that add up to make a big difference in a photograph.