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Tuesday, October 22, 2013

Talking Technique With Future Pros


Unlimited Depth Of Field • Panorama Techniques • Extending Long Lenses • Back To The Future

Labels: How-ToColumnTech Tips


This Article Features Photo Zoom

Ice Crystals. Using manual changes in focus, nine images and Zerene Stacker software, Lepp rendered a completely sharp image of a translucent bladder seed pod frosted with feathery crystals on a cold, clear Oregon morning. Canon EOS 5D Mark III, EF 180mm macro lens, 1⁄125 sec. at ƒ/16, ISO 200.

In my role as a Canon Explorer of Light, I recently presented a short, but intense seminar to the ASMP Student Chapter at the Brooks Institute of Photography in Santa Barbara, California. The event was especially interesting to me because I graduated from Brooks more than 40 years ago. It was a real treat to work with an SRO audience of young, fresh, enthusiastic, soon-to-be-pro photographers and their instructors.

Back in my student days, preparation for a career in nature photography wasn't part of the school's agenda; my instructors barely tolerated my sometimes outlandish efforts to incorporate my passion for nature into every assignment. So when I had these creative young people, my future fellow Brooks' alumni, in my clutches for an evening, I put together a program that featured my latest forays into extreme capture techniques as applied to nature and outdoor subjects. It really brought home to me the ways in which the huge technological advances of the last four decades have expanded my creative horizons. Here are some of the highlights from my presentation at Brooks.

Unlimited Depth of Field
For me, one of the most frustrating limitations of film photography was the inability to control and/or expand the areas of sharpness in an image. In the digital age, I use a variety of methods to achieve all the depth of field I want, where I want it.

These techniques are most revolutionary in macrophotography where a process called stacking—capturing the subject in a series of miniscule, precisely focused slices, then assembling the slices in post-capture software—is the way to defy physics and produce completely sharp images at magnifications far beyond life-size. In illustration of this technique, I wowed (and disgusted) my audience with a series of images of hideous, miniscule, dog parasites photographed at 10X and projected at wall-size in all their hairy, bloodsucking glory.

When working at magnifications of 1X or less, a photographer can make the sequential captures manually, either with integral adjustments in focus or the camera's position, but each slice of in-focus composition must overlap the next. This can result in many captures that, taken together, still achieve what seems like only a small amount of depth of field. But at high magnifications, depth of field is very limited—approximately 1.5mm at 1X with ƒ/11, and substantially less at higher magnifications. When I use the stacking technique for depth of field at higher magnifications, I employ a tool called the StackShot, available from www.cognisysinc.com. This focusing rail with a controllable step motor can move the camera from 1 micron to several inches per shot in a stacked image. I assemble the captures in Zerene Stacker (zerenesystems.com) or later versions of Adobe Photoshop (CS4 to the current CC) and Helicon Focus (heliconsoft.com.)

Stacking isn't only for macrophotography. I often use the technique for landscapes when the scene is beyond the capabilities of a single image at a small aperture. A typical composition would include important detail in the foreground, mid-range and distance, such as the iconic Arizona wildflower/cacti/mountain vistas David Muench captures with his 4x5 view camera. Now you can achieve this with your 35mm DSLR. Mounting the camera on a tripod is necessary to keep all the images in register as you manually rotate the focus ring on the lens to break the composition into numerous overlapping slices of in-focus sharpness. It can require as few as two, or many, images to cover the full distance within the framed scene. Finishing the image using stacking software will produce a sharp image from foreground to infinity.

Panorama Techniques
Back in the "good old days" of film, I captured lots of panoramas. The best I could do with them then was to make several prints and cut and paste them together to convey the entire scene. Years, sometimes decades, later, I resurrected those files, scanned the slides and assembled the panoramas in Photoshop. I still do that with traditional composite panos, but with much better quality and modern printers enabling high-resolution prints of 25 feet or more in size. Three of my favorite new panorama techniques are gifts of the digital age.

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