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| Photo by David FitzSimmons |
| Click photo to see a step-by-step slideshow explaining how the author got this image using Helicon Focus software. |
Extreme depth of field used to be the province of pinhole shooters and pricey view cameras, but now anyone with a manually-focusing camera, a tripod, a computer, and $30 can create images that are tack sharp from right in front of the camera to infinity -- even with macros and telephotos!
The secret to this new technique lies in the processing engine of Helicon Soft's nifty program, Helicon Focus, which takes the in-focus areas of multiple exposures of the same subject -- manually focused on different planes throughout the field of view -- and combines them into one, completely focused image with virtually unlimited depth of field. While the algorithms used to create final images are undoubtedly complex, photographers using Helicon Soft will find its operation quite simple.
Here are the three basic steps:
Step One: Find a subject that can be enhanced with an extensive depth of field. You might immediately think of micro and macro subjects, where depth of field is always minimal. Who hasn't taken a close-up of a flower and wished to have everything from the tip of the anther to the last dew-dropped petal in focus? Now you can. But don't just limit yourself to small subjects. Even landscapes can benefit from extreme depth of field. Imagine kneeling down before a mountain lake, keeping foreground flowers and background mountains all in focus without tilting lenses.
In fact, Helicon Focus allows photographers to capture images impossible even with huge view cameras. If a scene includes one object occupying a vertical plane near the camera and others in vertical planes great distances away, extremely small apertures are an often-employed solution. But Helicon Soft's program will produce much sharper results. The traditional technique of stopping down to f/16 or beyond and using the hyperfocal distance will render a scene reasonably sharp, creating a seemingly large depth of field. Remember, sharpness is relative. Depth of field has to do with circles of confusion, the technical term for what viewers accept as slightly blurred but apparently in focus.
Try this experiment: inspect an object at infinity in a picture taken at, say, f/16 and focused for the hyperfocal distance; it will not have the same sharpness as when focused at infinity itself. That's because distant subjects (and those close at hand) are mostly in focus, having fairly small-sized circles of confusion. With Helicon Focus, everything can be tack sharp -- the nearest tree and the distant hillside -- because the circles of confusion in the final, processed image are tiny. The results are pleasing and, if you think about it, natural. Isn't this the way our mind perceives and remembers scenics -- everything in focus?
Step Two: With your camera solidly mounted on a tripod, take multiple pictures, focusing progressively from the far away to the close by. I suggest that, after turning your auto focus off, you focus on the nearest subject, noticing the distance indicated on the lens barrel. Then focus on the farthest point and work backward. Take one picture; then refocus closer. Take another picture; then refocus closer, and so on. Don't base your refocusing on the lens's distance scale; instead, turn the focus ring in equal increments (degrees) between the distant end and the closest point. Also, keep the manual exposure the same for all images, and, as you turn the lens progressively back toward the closest part of the subject that you want to be sharp, try to keep your camera and tripod still. (If I'm outside, I often push down on the tripod, sinking the legs into the ground.) You may take as few as three or four pictures, or you may need many more. The software will process any number of shots.
Step Three: Believe it or not, now comes the easiest step. Load the images into Helicon Focus and let it do its thing!
The program is incredibly simple, so much so that I was processing images within minutes of startup. What's even more amazing is that slight movement from image to image is handled by the software (both camera and subject movements). Further, Helicon Focus corrects for the progressive magnification that occurs when you focus from infinity back toward the camera. And don't worry about the slight decrease in exposure that happens as you refocus some lenses. Helicon Focus even corrects for exposure differences. The accompanying photograph of the male giant water bug reveals all of these corrections. I photographed this hemipteran while he was perched atop a moving piece of wood!
After a brief time (ranging from less than a minute for a few, small files to several minutes for numerous, large files), voila! You will have a photograph with incredible depth of field. The real fun is zooming in to 100 percent, where all the details from close-at-hand to far away are in tack sharp focus!
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