Not just a
huge collection of
Elasmodiver.com contains images of sharks, skates, rays, and a few
chimaera's from around the world. Elasmodiver began as a simple web
to help divers find the best places to encounter the different
species of sharks and rays that live in shallow water but it has
slowly evolved into a much larger project containing information on
all aspects of shark diving and shark photography.
now more than 10,000 shark pictures and sections on shark
evolution, biology, and conservation. There is a large library of
reviewed shark books, a constantly updated shark taxonomy page, a
monster list of shark links, and deeper in the site there are
numerous articles and stories about shark encounters. Elasmodiver is
now so difficult to check for updates, that new information and
pictures are listed on an Elasmodiver Updates Page that can be
is an equation with three variables. Stay with me, its really not
that tricky. All you are trying to accomplish is to get the right amount
of light to hit the film or digital image sensor. The three factors that
influence exposure are:
speed or Isometric reading - you get to choose how sensitive your
film or sensor is. The more sensitive the film the faster it absorbs
light. Taking fast pictures means that your rapidly swimming subject wont
look like a blurred streak. Sensitivity runs between 100 ISO which is slow
to 1600 which is lightning fast. Why would anyone use slow film? Because
fast film speeds produce grainy images. That means that the colors are
blotchy or pixilated. Digital SLR cameras let you change ISO on the fly
but film shooters have to load whatever film they think they'll need
before they get into the water. If its darker down there than they thought
it would be, they have to sacrifice one of the other factors in the
equation to compensate.
- Or how big the hole is when the shutter opens. If you keep it small
(like a pin hole) the image will be crystal clear as long as you keep the
camera steady. That's great if you're shooting in really bright
conditions. Otherwise that tiny hole wont let in enough light and your
pictures will be too dark. No problem - choose a bigger aperture. Now
there is plenty of light getting in but its not all hitting the sensor or
film in the right place. The result is an image where the focus point is
crystal clear but everything closer to or further away from the lens is
blurry. This is called the depth of field.
Small apertures have a very long depth of field i.e. lots of the image is
in focus. Large apertures have a very narrow (short) depth of field i.e.
only one distance is in focus. Aperture sizes are called
F Stops. Small apertures are big F Stops and
visa versa. For example a wide aperture might be F2.5 and a narrow
aperture would be F20. This is done to purposely confuse amateur
photographers and stop them from turning pro.
Speed - this is how long the shutter lets in light before snapping
closed again. Its probably the simplest concept to wrap your head around
as long as you understand fractions. Basically, a fast shutter speed lets
in very little light and a slow shutter speed lets in much more. Its
measured in fractions of a second with 1/40th being really slow for
underwater work and 1/1000 being faster that you'll probably ever use. Why
not crank it way down to 1/40th and have a really small aperture and keep
everything in focus? because its too tough to hold the camera steady for
that long especially when your subject is swimming around.
whole lot of information but it condenses down to this: You want to
use the slowest film speed possible, the highest (smallest) aperture possible, and
the fastest shutter speed possible while still allowing enough light into
the camera to freeze into a nice picture.
OK, that's all well and good
but it doesn't give you any real settings advice does it? That's because
the lighting conditions on each dive are completely different. That's the
whole reason for all those possible combinations; so that you can take
advantage of different situations. What I can do is show you bunch
of images and tell you what I set the camera to in each case and why. That
should give you a vague starting point. Remember that you're trying to
expose the background correctly with the available ambient light. This has
nothing to do with making the colors show up on your subject which is
done using your
Shutter speed 1/100th
This Spiny dogfish picture was
taken in the dark and cloudy waters of British Columbia. Even though the
film speed is high, the shutter speed fairly slow (for a quick shark) and the aperture reasonably
wide, the background is still a little under exposed.
Because the dogfish was moving quite fast I would have
liked to increase the shutter speed to get a crisper image but that would
have given me an even darker background.
Shutter Speed 1/80th
Shooting a slow moving shark this close to the
surface on a sunny day, I could easily have shot using ISO 100 or even
lower to obtain
smooth images but my old Nikon D100 didn't offer that setting. Now I shoot with
a D2X which shoots as low as 100. The newer generations shoot with
virtually no noise right up to 1600 ISO so the relationship between
noise and film speed (ISO) is becoming redundant.
Shutter Speed 1/80th
Nice bright conditions at the
surface allowed me to shoot on my slowest film speed, but I still needed a
fairly slow shutter speed to gather enough light for the water to expose properly.
My strobes were set on high so that the shark would not be just a
silhouette against the brighter surface.
Shutter Speed 1/00th
This ghost shark was shot in
110ft in the semi darkness. If it had been in mid water the background
would have appeared completely black but its proximity to the reef allowed me to
expose the background nicely with my strobes. When you rely on strobes
alone, shutter speed can be cranked up as high as the strobes can work
that gives you a feel for some approximate settings but you don't have to
guess your exposures. Lots of digital and film SLR's come with
built in light meters and you can buy separate ones for those that don't.
The technology is complicated but using one couldn't be simpler. All you
have to decide is which part of your image needs to be exposed correctly.
If you are shooting a shark in the blue then you want a nice blue
background and not a shark in the dark. So assuming you have an SLR with
a menu, set it on manual and point it at an empty area near the shark.
When you half depress the shutter button and look through the view finder
you should see a gauge that tells you if your image will be under or over
exposed. Often this is displayed as a rule with minus at one end and plus
at the other. Now you can play with your aperture and shutter speed until
the display indicates that you are on zero (half way along the rule). Now
your water will be blue but only if you shoot in that direction. If you
move around the light will be different and your settings need to
Note: your reading will get
screwed up by the sun if you're pointing straight at it so make sure
you're pointing at the most neutral area of the water with regards to
Ok now you should have your
background exposure dialed in so all that you need to do is light your
subject correctly to bring out the color. If you're unsure how to do this
go back to
strobe use for a reminder.
Like most aspects of photography you can break the
rules and end up with some pretty cool results.
This Lemon shark image has a blown out background
creating a sharp contrast with the shark. Its tricky to make this work
because of the shark's white belly. More often than not you will end up
with a half visible shark, but if you're shooting digital you can afford
to play around and delete later.
The important thing is to light the shark well. A
silhouette shot in water this shallow is more likely to end up looking
like your strobe failed than an artistic attempt.
You want to over expose the background just enough
to turn it almost white but not so much that it begins to flare. And,
you need to crank up your strobe to expose the shark at the same level
as the sky which probably means shooting on or close to full power. If
your strobe isn't powerful enough to match the background light then
this shot won't work.
Bracketing: What your internal light meter thinks is a good light
level might not look so good when you download your pics. Also, they
aren't really designed to work underwater although it shouldn't make that
much difference. To make sure your exposures are correct you can take
extra pictures of each shot that are 1 or 2 F-stops higher and lower than
your light meter deems appropriate. This is called bracketing. There are
obvious drawbacks to bracketing especially for shark shooters. Firstly,
you'll run out of film or memory space three times faster, and secondly,
most sharks wont stop swimming to wait for you to adjust your F-stop.
I don't do a lot of bracketing.
I rely on my review screen that shows me a histogram of my digital image.
It shows me if any areas of my picture are completely blown out. Be
careful when using this as your reference because the back lighting on
these little screens often make your images appear brighter than they
really are. If you're more or less on the money, a little tweak in Photoshop will help you get it looking just right.
If you are shooting in RAW (a file type available
in all new DSLR cameras) the camera will gather more information than you
can see just by reviewing the image. So, in photoshop you can bring out
the hidden over or under exposed info until your image looks how you
intended it to. There are limitations; you can't turn a black picture into
a brightly lit masterpiece but the RAW file capabilities will certainly
help with minor adjustments.
Many pro shooters still bracket
believing that its better to be safe than sorry.
In a Nut Shell:
Choose the right ISO for the dive.
Try to use high F-stops to increase your depth of field
Try to use fast shutter speeds to avoid blurry sharks
Train your light meter on a neutral part of the background
Set your Digital SLR on RAW if you have that option
If you cant review your images, bracket
Andy Murch works as a Photographer for Shark Diver