Unlimited SharpnessHelicon Focus gives you the ability to cheat depth-of-field limitations
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By George D. Lepp And Kathryn Vincent Lepp
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Page 2 of 3
| Macro images of new Jefferson dollar coins. BELOW: This image at 1.3x is made up of 12 captures taken at ƒ/11 with a shutter speed of 1⁄250 sec. Four Canon EX flashes were used for lighting. A Canon EOS 5D was the camera of choice. ABOVE: This macro image is at 1x with the same equipment and settings (your choice).
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Using Helicon Focus
The basic concept underlying Helicon Focus is deceptively simple. The photographer takes a series of matched images, overlapping the focus of each shot with the next until the entire field is covered. Helicon Focus automatically adjusts and resizes the images, which is important for macro photography, and it equalizes the brightness of adjacent images. It then merges the frames, retaining only the in-focus portions of each image. The result is a sharp composite. With advanced planning while capturing shots, the photographer can control the areas of focus as desired.
Despite the realignment capabilities of the program, it’s necessary to work as precisely as possible, using a tripod and, for macro photography, a focusing rail to assure that each shot matches the adjacent frames. Use a remote release and lock up the mirror if needed to minimize camera movement. Then, follow these steps.
• Determine the area that needs to be rendered in focus—it need not be the entire field of view. That is,
the bug could be in focus while the
leaves behind it are blurred.
• Set the camera to manual focus,
and turn off image stabilization.
• Use manual exposure, keeping
the shutter speed the same
throughout the series.
• Choose an ƒ-stop that offers
optimal sharpness (generally, ƒ/11
or ƒ/16) and enough depth of field
so that the focused area in each shot
can be overlapped with that of the
preceding image.
• If you want to maintain an
out-of-focus background,
choose a large ƒ-stop (ƒ/5.6 or ƒ/8).
It will take more images to capture
the sharp area, but you can retain
the soft background effect.
• Move the focus through the field
of view by turning the focusing
ring to capture a series of shots that
achieve the desired overlapping
increments. In macro, it may be
necessary to adjust the camera/lens
combination along a focusing rail,
moving the working distance
to change the area of focus.
Be on the lookout for the following potential problems:
• The subject can’t move during
the series of exposures. If the
subject is influenced by wind, you
may need to photograph in early
morning or late afternoon or find a
way to stabilize it. It’s possible to
use Helicon Focus on live subjects,
but you need to work quickly.
• Large foreground features can be
problematic. As the focus shifts
past them, they tend to “bloom”
out of focus and obscure the areas
behind. Choose an angle of
approach that minimizes the
foreground’s impact on the
total field of view. Experiment
with different perspectives.
• If your composite image shows
bands of softness interspersed
with sharp areas, you haven’t
sufficiently overlapped one or
more images in the series.
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