Image of the Week: Ocotillo Shadow, Abandoned Cabin, Anza-Borrego State Park, CaliforniaDo a little Photoshop in-camera. Adobe Photoshop's "Lens Distortion" filter makes it very easy to correct common distortion and perspective effects caused by extreme wide-angle lenses or acute camera-to-subject angles. One of the most common corrections a photographer may perform is to counter the "keystone" effect that occurs when one places the camera low and shoots up at an oblique angle to the subject, causing vertical lines to converge in the top of the photo. Most of the time, this effect goes unnoticed. But when you shoot subjects that have obvious vertical lines that show profound keystoning, it's time to take action. Yes, you can fire up Photoshop, go to Filters > Distortion > Lens Correction and play with the sliders until the distortion effect is countered. This works well a great deal of the time, and I use it often. The only drawback is that this filter reduces your image's resolution; the distorted area is squeezed and reduced to bring it inline with the rest of the image. Sometimes, to get proper parallel verticals, the correction is so strong you end up losing valuable image area to the correction-induced crop. If you need to go big with an image, or the retention of fine detail is a must, this solution might not be the way to go. This is just the kind of job where a large format field camera shines. A field camera is nothing more than a view camera designed for portability. Both types feature moveable lens and film planes, allowing you to tilt, shift, rise/fall, and swing the two surfaces relative to each other. The result of using these movements allows the photographer to finely control the angle of the plane of focus, the apparent size of objects in a scene, and to correct perspective effects caused by acute camera-to-subject angles. For a full treatise on the use and operation of view cameras, I highly recommend Steve Simmons' Using the View Camera. When I photographed Ocotillo Shadow, I wanted to capture the rear window framed within the front window, but the angle required the camera to be placed far to the right of the composition. I needed the front window to fall on the right of the image and the shadow of the Ocotillo limbs to "crawl" from the bottom right to top left. To accomplish this arrangement, I shifted the lensboard to the far left. This produced the composition I envisioned without compromising the lens-to-subject relationships. Best of all, the resulting negative needs no further adjustment in post production and reproduces very well at large sizes. Technical DataOcotillo Shadow, Abandoned Cabin, Anza-Borrego State Park, California was photographed with a Tachihara 4x5 Field Camera and Schneider Symmar-S 150mm ƒ/5.6 lens on TMax 100 B+W negative film, EI 50. The exposure was unrecorded. |
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