Page 53 - CEREC Q2 | 2014

QUARTER 2 | 2014 | CERECDOCTORS.COM | 51
Fig. 5a: Ring flash from Canon. The ring
flash is mounted on the front of the
lens and allows proper illumination
of the teeth. This is best suited for
photographing posterior teeth
Fig. 5b: Twin flash from Nikon.
This is one variation of the twin flash.
This allows a better capture of
anterior teeth
Fig. 6: F-stop settings represented as a
graphical depiction of how much the
opening is on the lens.
f/16 f/11 f/8 f/5.6 f/4 f/2.8 f/2
$500 to $1,000. These mid-range
cameras will give you all the features
you need for proper photographs. The
critical things you want to look for in
a digital camera body are the ability to
change lenses, the ability to adjust the
F-stop setting and the ability to adjust
your shutter speed. (More on F-stop
and shutter speed later). Higher-end
cameras will give you more settings
such as ISO and white balance, just to
name a few, but the bare minimum is
what’s listed above.
CHOOSING AND USING YOUR LENS
A camera body is the first step in taking
good dental photographs. However, it
is also the least important component
of the required equipment for photog-
raphy. Whether you have a $500 camera
body or one that costs 10 times as much,
most of the lower-end camera bodies
will give you what you need to capture
quality dental photos.
The proper lens, however, becomes
much more critical once you start snap-
ping photos. The recommended lens is a
100 mm macro lens (Fig. 2). Obviously,
if you have a Canon body, you will have
a Canon lens, and a Nikon body will
have a Nikon lens. The 100 mm macro
lens will allow you to get a close-up of
approximately four to six teeth (Fig.
3). The disadvantage of the 100 mm
macro lens is that it is somewhat
bulky and heavy. Not a big deal for
most clinicians, but some of the smaller
members of your teammay find that the
camera body and lens (and flash – we
will discuss that next) could give them a
bit of a workout to take the photographs.
One option is that you use a 60 mm lens
that accomplishes the same thing — but
is a smaller, lighter lens, and therefore
unable to get such close photos. While
the 60 mm lens will not get as close as
the 100 mm lens, for 95 percent of the
cases that we document and film, it will
suffice (Fig. 4).
CHOOSING AND USING YOUR FLASH
With the camera body being the least
important and the lens being the next-
most important item of the camera set
up, without a doubt, the most important
aspect of proper dental photography is
the flash. A normal flash on the top of
the camera will not work to properly
capture the colors intra-orally. Simply
stated, the camera-mounted flash will
not reach the “subject” — in this case,
the teeth. The camera-mounted flash
will simply be blocked by the lips,
cheeks and other oral structures.
For dental photography,
what one needs is a flash that
is mounted on the front of the
lens, away from the back of the
camera. Two main choices are
either an anterior twin flash or
a ring flash, both of which are
shown (Figs. 5a-5b).
My personal preference is to
use a ring flash to photograph
posterior teeth because you
will get a better illumination of those
teeth. For anterior teeth, my preference
is to use the twin flash, which sepa-
rates the flash unit from the lens, and
will give you softer and more accurate
colors and rendition of the teeth.
This does not mean that the dental
clinician needs to buy both a ring
flash and a twin flash for anterior and
posterior indications. My recommen-
dation is, if you are looking to get just
one flash for dental photography, get
the ring flash as it’s easier to handle
for new users and more universal in its
application.
CHOOSING YOUR CAMERA SETTINGS
So, now that we have the equipment
needed for proper dental photography,
let's talk about the proper camera
settings. There are a lot of important
settings but the ones that are most
critical for the scope of this article are
shutter speed and F-stop.
F-stop refers to the amount of light
that a camera lens will allow to hit the
5b
5a
6