Tuesday, May 29, 2007
The Really Wide View
Panoramas are hot with a lot of clients right now, but shooting them well takes specialized skill and attention to detail
Film cameras can be good tools to use, especially if you enjoy the process of shooting film, but all of these cameras can be temperamental, and using them takes some special attention to the quirks associated with their unusual designs. Also, they're very expensive, and, of course, you can't be certain you got the shot until the film comes back from the lab. They make great cameras, and you can produce outstanding images, but the costs and limitations are considerable.
Like everything else in photography, digital technology fundamentally changed the panorama. The main benefit of digital for panorama shooters is the ability to use software to stitch a number of frames together. The resulting image file can be of almost limitless resolution. Digital panoramas can be actual mosaics, instead of just stitching them together in one dimension. In the July/August issue of Digital Photo Pro, we featured the work of Jeff Liao in “Broadway To Queens.” A rapidly rising star, Liao uses an 8x10 view camera, but he actually stitches several frames together to create his panoramas. The frames are put together in mosaics in some cases, and the resulting image files are massive. In fact, the real limiting factor in creating a digital panorama is the power and storage of your computer!
In The Darkroom
The main disadvantage to digital stitching is the time it takes in front of a computer. Putting panoramas together takes time and skill and a lot of RAM. There are plenty of amateur-oriented programs that will do it automatically, but most of these packages aren't suitable for professional use except for making a rough “sketch” from low-res JPEGs. To do the job well, you're going to be hunkered down in front of Photoshop making edges line up properly and taking care to get vertical lines straight. If that doesn't sound like fun, add in the cost of a professional retoucher when you make your bid for the job, and let someone else do the digital darkroom work.
The biggest issue you'll face when stitching is likely to be lining up the individual frames properly. Even if you anchor the camera to a solid tripod and take care to rotate the camera with plenty of overlap, you can still have issues. When you rotate the camera body on a tripod, you're rotating around the image plane, more or less. This causes a slight but noticeable change in perspective from one exposure to the next. When you go to line up the frames, you'll end up with elongations and/or compressions that just won't look quite right, and that adds up to more time in front of the computer or a bigger retouching bill.
To minimize these sorts of distortions, you can use a specialized panorama-shooting apparatus on your tripod. This bracket system changes the rotation point from the image plane to the lens' nodal point. The nodal point is simply that point within the lens where the light rays cross as they pass through the optical system. Rotating around the nodal point eliminates parallax problems and makes it much easier to put together a good panorama.
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