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Greetings!
Welcome to our monthly newsletter designed to keep
you informed of the goings on in the wonderful world of
Digital Photography and Video. We hope you find this of
interest and if you have a topic you would like us to
cover in future newsletters, please let us know.
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Part Two: Painting the Underwater World
with Light |
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In underwater photography, you paint the
picture with light: ambient light, strobe light,
and a combination of the two. Your strobe is your
brush, but before we begin painting, let’s review
some basics about strobes.
The flash
modes we have available in underwater strobes are:
Manual, Auto, TTL (Through The Lens Metering), and
Slave:
Manual mode: When you
determine and pre-set the camera’s ISO, aperture,
shutter speed, and estimated strobe-to-subject
distance. Light intensity from the strobe must be
equal to that of the aperture. This mode can be
tricky. Light meter readings must be right on to
get the right f-stop and shutter speed cranked
into your lens and camera. Compatible only with
Single Lens Reflex (SLR) cameras and some newer
digital point-and-shoot cameras that offer limited
manual settings.
Auto mode: The
strobe has a built-in sensor that automatically
measures reflected light intensity from strobe to
subject. Used with SLR and pre-flash digital
camera systems with the required sync cord or
fiber optic cable.
TTL: When the
camera and strobe are set to TTL, the light
passing through the lens from the strobe is
measured electronically by means of sensors within
the camera. The camera and strobe communicate
electronically. Light intensity varies with strobe
to subject distance. The TTL mode is available
only with SLR camera systems featuring TTL
compatibility.
Slave: Strobes
offering the slave mode fire when the light from
another strobe activates the slave sensor. This
mode is used for dual strobe photography with SLR
cameras and with digital camera systems that
require fiber optic cables or electronic sensors
to activate an external strobe from the camera’s
built in pre-flash strobe.
Note:
Today’s digital cameras for underwater photography
operate different from the film camera systems of
yesteryear. Many difficulties related to the
compatibility of strobe and digital cameras have
opened up a Pandora’s box of problems. Before
purchasing a system talk to a photo pro for
recommendations on what strobe system is best for
your needs and budget.
After you set
the flash mode you will be ready to take
pictures.
- Aim the camera. Avoid when possible
aiming the camera downward onto a scene/subject.
This angle produces two-dimensional pictures
with little or no contrast. However, do it
anyway if the subject is something rare,
fleeting, and you may never have the opportunity
to see it again! Use a slight upward angle with
a slight tilt off-center to frame the
subject/scene. Yes, we love to take pictures of
fish. Unfortunately fish are smarter then people
in their underwater environment and must be
approached carefully. Slow frontal approaches
usually get the eyes, mouth and body of the
fish. Quick and abrupt lateral (side) shots
usually get the tail of a fleeing fish (ugh!).
- Aim the strobe. This may be the
hardest skill you will ever have to master in
underwater imaging. First you need to know about
actual image versus apparent image. Subjects
underwater appear closer than they actually are.
Example: Objects 4 feet away (actual distance)
from the camera/strobe appear to be at 3 feet
(apparent distance). Strobe light travels in a
straight line, therefore, aiming the strobe at
the center of the image as you see it (apparent
distance), will cause the light to fall short of
the image (actual distance). The strobe must be
aimed behind the subject as you see it, never
across in front of it.
- Position the strobe. With articulated
strobe arms, you can position the strobe head
and direct the light beam in a countless number
of ways, but basically, it boils down to:
- Front lighting. Strobe light positioned at a
45-degree angle and directed slightly off-
center of image. Used primarily in macro and
close focus photography.
- Top off-center lighting. The most realistic
type of lighting. It emulates how sunlight
illuminates on land. Angling the strobe at a
45-degree angle and aiming the strobe behind the
subject minimizes backscatter.
- Side lighting/rim lighting. Place the strobe
parallel with the camera and the light directed
at the subject. Creates a three-dimensional
effect with long shadows, texture and contours.
- Overhead lighting. Place the strobe directly
above the subject. The light will be directed
downward emphasizing heavy shadows and textures.
Dramatic pictures can be achieved. Experiment.
- Back lighting. Place the strobe slight
above, off-center, and behind the subject. Take
care not to point the strobe directly into the
lens of the camera. This type of lighting can
produces halo and translucent
effects.
Advanced
Technique: Balanced light. Balanced light is
the term used to describe ambient light filtering
down through the water column combined with a
touch of artificial strobe light on the
foreground. When done correctly this type of
lighting creates a picture of three- dimensional
quality and artistic value. Getting the exposure
value of the ambient light to match that of the
strobe light can be tricky.
The following
rule-of-thumb principles will apply when using an
SLR or a point-and-shoot camera that offers
aperture settings. Experiment. Practice makes
perfect.
If the background light is f/22,
the strobe-to-subject distance is one foot.
If
the background light is f/16, the
strobe-to-subject distance is two feet.
If the
background light is f/11, the strobe-to-subject
distance is three feet.
If the background
light is f/8, the strobe-to-subject distance is
four feet.
I’ve experimented shooting
balanced light shots with Manual, Auto, and TTL
strobe settings. The newer SLR and point-and-shoot
cameras have very sophisticated metering
technology and do a great job. You may want to try
it and let the camera do all the work.
FAQ - Frequently Asked Questions
Q. How many strobes are enough?
A. I normally use one strobe for macro
and close focus wide-angle. I normally use two
when using super wide-angle lenses. With
wide-angle it is important to know the degree of
coverage your wide lens covers. Purchase the
strobe/strobes that will cover the subject or
scene with adequate light. Note of interest, one
strobe with 95 degrees coverage will usually give
enough light to paint the picture.
Anecdote: Heard a good one recently. A
young sales person at a consumer dive show was
giving a pitch to several people that you need to
use four strobes when shooting wide-angle for
maximum coverage. FYI: I use a 10.5mm wide lens
and most of the time I use one strobe for artistic
lighting and two max when I want to fill the frame
corner-to-corner. Talk about overkill and
especially overselling.
Q. Can I
use my strobe that I used with my film camera?
A. Probably not. The answer in detail
is in the July newsletter. Click here
to read Part 1 in my July Newsletter..
Q. I’m a beginner. What should I
buy, and what is the shelf life of a digital
camera?
A.The digital age came upon us
gradually. It is now traveling at near the speed
of light. Manufacturers are competing aggressively
for the market. Digital camera technology doubles
about every two years. My newsletter of April 06
is helpful. Click here
to read my April issue.
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Private Lessons |
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Education is the key to
successful underwater photography
If you are serious about learning how to be an
accomplished digital still photographer or
videographer, please join us in La Paz at The
Underwater Imaging Academy October 10 – 16. See
our website for details. www.JoeLiburdi.com
Closer to home, Joe is offering private
photo lessons at a reasonable fee of $50 per hour,
minimum three hours. The classes are one-on-one
and conducted either at his home in Aliso Viejo or
at Liburdi’s Scuba Center in Costa Mesa. By
appointment only. Call 949-448-0499 or e-mail Joe
at orca2@cox.net .
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PADI Digital Underwater Photographer
Certification |
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New PADI Digital Underwater Photographer Course
will be given at our Underwater Imaging Academy in
La Paz. For details please visit www.JoeLiburdi.com
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Cell Phones on Vacation |
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By Craig Oberlin
When you're traveling on a dive trip
internationally, a cell phone is becoming
essential to keeping you in touch with work and
loved ones. Unfortunately, most of the time your
cell phone isn’t going to work.
To
maintain cell phone service while abroad, you have
several options.
- Buy an international plan from your current
service provider (not always available nor easy
to do, expensive roaming rates).
- Rent an international cell phone at the
airport (not always available, expensive).
- Take advantage of the local cell phone rates
in the country or countries where you'll be
traveling by purchasing prepaid calling SIM
Cards.
To help you evaluate your
options, let’s look at the underlying
technology.
GSM
Outside of the
United States and a handful of countries, the
world's cell phone carriers operate on a unified
standard called GSM (Global System for Mobile
connectivity). The GSM standard requires a
GSM cell phone and a SIM
card. The SIM card is a small chip that
allows your phone to connect with a local wireless
carrier in the country you are visiting.
There are currently four frequency bands
used by GSM cell phones. Most countries use
a combination of the 900 MHz and 1800 MHz
frequency bands. Here in the U.S., we use a
combination of the 850 MHz and 1900 MHz frequency
bands (Cingular and T-Mobile being the primary
U.S. based GSM carriers.)
GSM cell phones
are available in dual-band, tri-band and quad-band
models. A dual band phone is adequate if you only
need service in Europe, Africa, Australia, New
Zealand and Asia (except for Japan and South
Korea). In North America as well as overseas, a
tri-band cell phone or quad-band is the best
choice.
SIM Cards
The SIM card
basically “identifies” your phone with your cell
phone carrier. In the U.S. most carriers configure
the cell phone to only accept their SIM card,
called “locking.” For international cell service,
you will need a cell phone that is GSM
SIM-unlocked.
Some providers never unlock
handsets, even after a customer has fulfilled
their service contract. Other providers will
unlock phones if the customer has an active
account in good standing. If your carrier won’t
unlock your current phone, there are independent
companies that will or will sell you a unlocked
phone at competitive prices.
Evaluating
your Options
If you have a tri-band or
quad-band GSM cell phone and your carrier offers
international plans, this will be one of the
easiest solutions. Realize that you may pay as
much as $1.00 per minute PLUS a monthly service
charge. With a tri-band phone, check that the
frequencies are correct for the countries you are
visiting. If they aren’t, it’s usually possible to
rent a quad-band phone from your carrier.
Another option is to rent a cell phone
from the country you are visiting.
The
last option, buying a pre-paid SIM Card, is likely
to give you the most flexibility and the cheapest
rates. Unlike the other options, your outgoing
call rates are just fractions of a dollar per
minute even for international calls back to the
U.S. Plus in nearly every country you get
unlimited, FREE incoming calls.
If you
want the security and convenience of a cell phone
when away but want to escape from incoming calls,
you can always tell them that you were underwater
when they called.
For the complete,
unabridged article on cell phone for travelers,
click here
to see our Traveler's Resources.
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Photo Gear for Sale |
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Previously owned equipment
from a man you can trust.
New this month!
SONY TRV-30
and TRV-700 and Light & Motion Stingray
underwater video systems. 
Plus! Rare
regulators.
For
these and more good buys, check out the used photo
equipment section of our website by clicking here.
E-mail inquiries to Joe at orca2@cox.net.
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