| For readers who are not familiar with
the Stromm housing, no controls have been offered in the past
to change any camera settings underwater on this housing.
The housing was fitted with only one control which autofocuses
the lens and trips the shutter. This, according to advertisements,
theoretically limits the ways in which a photographer can
screw up a photograph.
My guess is that you bought your housing at least a couple
of years ago—when the 808 was in its hey-day. The manufacturer
has been expecting to offer an aperture control for some considerable
time now, although for years it had not been forthcoming.
It is my understanding that an aperture control, and an exposure
compensation control, after a multitude of delays, did finally
come forth and are now available on housings for more recent
model cameras such as the N90 and N90S. The controls can be
retrofitted to your housing. Good news here! Now you have
two brand new ways in which to screw up your photos! On the
other hand, perhaps you can be trusted to use this new flexibility
to your advantage to force the camera to surrender a higher
yield of properly exposed photographs—back to this proposition
in a moment.
It is actually quite possible to do a lot of good photography
with a preset camera which has the computerized capabilities
of the 8808 and its relatives. Doing fish portraits and macro
shots on the same dive, however, will impose limits. If you
set up for macro, odds are that you will most often require
as much depth of field as you can get. This means something
like f22. At this f stop, your background will either be strobe-lit,
or it will be black. You can do macro with this setup until
the cowfish come home and you aren’t really giving up
a whole lot of creative control, especially if you have an
articulating strobe arm on your strobe (or strobes), and can
light from a variety of directions and strobe-to-subject distances
with a variety of lighting ratios. You can do fish portraits
also with a strobe-lit or black backgrounds. Fish portraits
with naturally lit blue water backgrounds are, for all practical
purposes, impossible at f22. You are limited by how far forward
you can position the strobe to keep the strobe-to-subject
distance short enough to give a good exposure at f22. This
usually means keeping the strobe within a foot of the subject.
If you look at the geometry of your 60mm lens, which has an
angle coverage of about forty degrees, you will find that
you can take a photograph of a fish which is something under
a foot long, filling about two-thirds of the frame with your
subject—an average composition for a fish portrait—by
moving your strobe to about a foot in front of the housing.
This is just about all the practical reach you will get with
a normal strobe arm.
When you’re using a strobe, there are actually two
images recorded on the film every time you trip the shutter.
These are, hopefully, perfectly superimposed to appear as
a single image. There is an available light exposure, and
also there is an image recorded by the artificial light from
your strobe. The camera’s computer will monitor and
regulate either, both, or neither of these images, depending
on how you set the controls. If you choose an automatic mode,
such as aperture or shutter priority or a program mode, the
camera will attempt to give you a nice 18 percent gray, normal,
day-lit-like available light image and will turn off the strobe
when an "average" exposed frame is achieved. In
a macro situation, there is almost never much available light
around, so the camera will take extreme measures to get some
light on the film. In shutter priority, the lens will open
up all the way—resulting in zip depth of field! Most
underwater strobes are designed for the Nikonos. Your camera,
and all Nikon cameras with TTL capability, including the Nikonos
and with the exception of the F3, have the same system of
communication between camera and flash. This communication,
called dedication, allows the strobe to signal the camera
when it is ready to fire, tells the camera when is has fired
full power, and sets the camera’s shutter to a speed
that is flash-compatible. When the dedicated TTL strobe which
is connected to your camera is turned on, your 8008 will "float"
its shutter speed between 1/60 and 1/250 second, as will the
rest of the Pro Nikons (F4, N90, N90S—also the N70).
The 1/250 is the highest shutter speed at which a normal camera
movement will not result in a blurry available light image—most
of the time. This will yield good results, as long as the
strobe you are using is dedicated to the camera. Note that
when a TTL strobe is used, you will get a TTL exposure in
all exposure modes, whether automatic or manual. The exposure
mode selected only regulates the ambient light exposure.
When you set your camera to aperture priority, at f22, you
will virtually always be shooting at 1/60 second. At f22 at
1/60, you will be okay for your macro and fish shots as mentioned
above. If you select a program mode, you’ll be 1/60
at whatever aperture gives a good available light exposure.
You should get nice fish portraits with a nice blue water
background—you’re dead in macro at wide open.
If you want macro and fish on a dive, best set your camera
at f22 at 1/60 or 1/125 in manual mode, or f22 in aperture
priority. If one were to be using a camera with dedication
to Nikon strobe control, or an older Nikon which only limited
the higher end of the shutter speed range to keep the shutter
speed at sync or below, one likely would be doing macro wide
open at maybe thirty seconds. This will be enough to superimpose
a smeared "properly exposed" sludge of a mostly
out-of-focus image over your perfectly exposed, perfectly
sharp strobe-lit image.
If you retrofit an aperture control to your housing and
use either aperture priority or manual, you can do macro and
just about any fish photography that suits your lens—no
problem. I would add the exposure compensation control for
the greater flexibility in tweaking your TTL.
I like center-weighted metering for macro. This is what
everyone has used for thousands of years—it works! You
can use matrix, but now you are giving power to the chip—and
power corrupts! Generally, in macro, most of the center of
the frame is out of about the same reflectance. If this is
not so, and you can’t access exposure compensation,
you’re shot down anyway. Matrix essentially is going
to step up and decide what part of the frame is subject, and
what is background, or some other entity not important enough
to be properly lit. Your 8008 will weigh meter data from its
five-segment grid (eight in later cameras), then consult its
algorithms, stored data, the Holy Bible, two astrologers,
and the Podiatric Compendium, and then render its judgment
in the form of a TTL exposure. M If it gets lucky, it will
probably give the same exposure as the center-weighted meter
would have. If it decides, however, that some part of the
foreground or background is the subject—you lose. Matrix
can frequently do an excellent job in wide angle and open
water fish portraits, but macro is probably not its forte.
Single serve autofocus is probably more friendly that continuous
servo in most macro and fish photography. Both systems have
their strengths and weaknesses. Read on, McDuff! Others quest
to know how they should oughta autofocus.
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