Correcting Lens Distortion in Architectural Photographs Using Photoshop Elements
I started out as a professional architectural photographer taking images of landscapes and buildings for interior designers, design-build contractors, and architects. Some of my first photography assignments were for a furniture catalog, way back in the late 1980's. One thing I've learned along the way is that built environment professionals should know how to properly photograph their work. Let me be clear, using a professional photographer for your largest or most important projects (or even a majority of your projects) is highly recommended. But with content marketing being the most effective way of marketing services, capturing images of less important projects is a habit you should form. The reason is simple, knowing how to take and edit architectural photographs distinguishes professionals from the iPhone amateurs amongst us.
Keystone Distortion in Architectural Photographs
If you take architectural photographs now, you may have noticed images of buildings that appear to be leaning backward or angled to the side. This is a common dilemma in photographs of buildings that can cause a subconscious uneasiness in viewers. Assuming these images are for marketing, the last thing you want is prospective clients feeling that something is wrong with your work. Proper post-production techniques will solve the problem, and Adobe's Photoshop Elements has easy to use distortion correction tools that will make your buildings appear vertical.
So why is a keystone effect such an issue with architectural photography? Lens distortion, the bending of light entering your camera, is part of nearly every photograph. With architecture, the highly linear nature of the subject combined with the size of buildings exacerbates this effect. Viewers expect to see a building with straight lines and right angles. Distortion works against viewers seeing your architecture for the design and encourages them to wonder what the problem is. The following advice will help you eliminate the uncomfortable feeling viewers get when seeing an image with distortion.
A Tripod and a Bubble Level is a Must Have
When shooting architecture, it is imperative that you use a tripod and a bubble level. If your camera is level, the subject will be too. Unless you're photographing Bonanno Pisano's tower of Pisa. A tripod enables narrow apertures and longer exposure without the resulting blur that comes with hand holding a camera while using slow shutter speeds. Tripods also allow you to shoot multiple exposures of your subject and combine them later in Photoshop Elements. This process is called as HDR or High-Dynamic-Range photography, and it is useful when you have different light levels in different areas within a scene. An example of this an interior design image that contains a window with bright sunlight and dark areas caused by shadow areas. I spent years souping 4" x 5" and 5" x 7" sheets of film using Edward Weston's PMK or Pyro-Metol-Kodalk developer solution to get what is now possible with a $800 Sony Alpha camera and a $90 software program.
Camera and Lens Choice
The camera and lens you choose will have an impact on the final product. And while post-production techniques are capable of vast improvements, using the best lens for the subject can help eliminate or lessen the burden after the fact.
Normal Camera Lenses
A fixed-focal-length lens of about 50mm is the standards for most "normal" lenses on full frame cameras. Their shape minimizes distortion and approximates the angle of view the eye sees. So why not use the lens in every situation? Because, without telephoto or wide angle options you're forced to shoot only when at the perfect distance from your subject. As anyone who has tried taking an image in a bathroom or of a building across a major street will tell you, this isn't always possible. As convenient as it might be to imagine the world with no small rooms, tall trees, or busy traffic to keep you from shooting in the middle of the street, it's not reality.
Wide Angle Camera Lenses
Wide angle lenses allow you to capture more of a scene. These lenses are usually between 16 and 35mm in length, and they are useful in almost every architectural shoot. However, the result can often be a "fish-eye" image with heavy distortion. A wide angle lens expands the amount of a scene that is captured and in the wrong hands can portray an insect-like vision. We've all seen close up images of dogs taken with a wide angle lens. It gives them the comical appearance of having an extraordinary long nose and ears that are set way back. This look or syntax may be serviceable for a funny greeting card or a rock band's album cover, but it won't do any architectural work justice. Use a wide-angle lens judicially. They are invaluable in tight spaces, for sweeping landscapes and for maximizing depth of field. Depth of field is the area within a scene that remains sharp and in focus. It is controlled by your choice of aperture and size of the lens. A smaller aperture and a wider lens will result in greater sharpness from close to far.
Telephoto Camera Lenses
My favorite lens for landscapes and exterior shots of buildings is a slight telephoto such as a 70mm on a full frame digital camera. The famous fine art photographer, Minor White almost exclusively used an 180mm lens on a 4" x 5" camera. Telephoto lenses are good for flattening a scene giving your images a compressed look. I find this form of lens distortion makes architectural images more appealing. telephoto lenses are also good for throwing the background of a scene out of focus. The longer the lens, the more shallow the depth of field.
How To Use Photoshop Elements To Rescue an Overly Distorted Image
Adobe's Photoshop Elements is an inexpensive and powerful editing tool. It can be used to remove lens distortion in minutes. The Following are the steps you take to remove lens distortion in Photoshop Elements.
Step One - Open the file you want to fix.
Step Two - Choose "Filter" and "Correct Camera Distortion" from the top menu. This will bring up Photoshop's Camera Distortion Editor, which superimposes a grid on top of your image.
Step Three - Start by adjusting the vertical perspective to make the building appear more upright. (This is what you want to adjust if the building seems to be falling backward in the frame.) Depending on the original shot, you may be forced to stop short of perfect verticality; otherwise, you could crop the top of the building out of the frame.
Step Four - The next step is to remove any additional lens distortion with the "Remove Distortion" slider. Moving the slider to the left will cause your image to bulge in the middle while moving it to the right will make the center skinnier. Pick a line within the photo that you want to appear straight (curbing, road signs, etc.) and use it as a guide to achieve balance in your photograph.
Step Five - To fix any leaning to the right or left, use the dial rotate the image. If the dial's increments are too broad, just enter the number manually. It may take a few minutes to figure out the perfect number—even fractional values can have a major impact, so start small.
Step Six - Crop your image as your edits will have added white space in the corners to compensate. Making these crops will reduce the ultimate dimensions of your image, so allow plenty of space around your important subject matter when taking the image. As long as you have enough detail and clarity, keeping more space around the edges will allow you to be more aggressive with distortion removal without losing critical data from your image.
Step Seven - Save your image. If you are using the image online, I suggest you use the save for web option and size your images 1500 pixels at the longest length. This will reduce the file size and allow your web pages to load quickly. Page speed is a factor in search engine optimization and will contribute to whether your website gets found online.
To recap, the best-case scenario is the use of a tripod and bubble level to keep your camera parallel with your subject. Using a ladder to get higher as opposed to pointing up with your camera and dropping lower to the ground without pointing down will save you all sorts of post-production efforts. Use the right lens for the right scene and run your images through a post-production process using Photoshop Elements and the step-by-step guide outlined to eliminate distortion. It takes only four of seven tweaks of the Correct Camera Distortion tool to ensure your building is straight. Just remember that the more distortion you need to correct, the more you'll eventually need to crop from your image.
Raise your architectural photography to the next level with the right equipment and post-production work in-house.
About Michael Conway and Means-of-Production
My firm builds Squarespace websites, Houzz profiles, and content marketing and advertising solutions for architects, interior designers, design-build contractors and landscape design firms. Our all-in-one tactics attract the right clients with exceptional architectural photography and brand messaging that sets you apart from the competition. Contact me for a free-of-charge consultation and marketing review. It takes about 40 minutes and you'll be provided a list of actionable improvements designed to solve your specific marketing problems.