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Lenses:
Part 3: Macro vs. Close-up (continued)
It would have been almost impossible to the capture the drumfish
on the previous page without a macro lens: they retreat into the corals when a diver approaches
too near.
Macro lenses are essentially short telephoto lens coupled to an
extension tube: characteristically they are very sharp and fast lenses.
Macros generally require the additional purchase of an extended
port
for your housing, since they extend further outward than standard lenses.
The key to getting great macro
photos is patience. Macro lenses have a shallower depth-of-field
than wide-angle lenses, so focusing is critical. The best
approach for macro is "pre-focusing" if possible.
Pre-focusing is a technique I've
used routinely for most of my macro photography, but it only works
in manual-focus mode. Normally I set the distance on the
lens in advance, say to 3 feet, adjust the strobe into the
appropriate position, and then patiently inch my way towards the subject. This allows me to maintain a respectful
distance from timid sea creatures, but get close enough to fill the
frame. When the subject finally becomes sharp in the viewer,
all I have to do is press the shutter control.
Even with auto-focus lenses,
pre-positioning the strobe and then staying within a certain
distance from the subject, is a recommended technique. |
