Digi-Cams for Dermatologists
Steven Emmet
Wednesday, October 15, 2008
Film is dead, it has gone the way of the daguerreotype and
calotype. As DVDs have replaced VHS, digital cameras have replaced
film cameras and for pretty much the same reason; digital cameras
are easier to use.
But why would dermatologists want a camera, even a "digi-cam" in
their office? If, like many dermatologists, you are doing any
cosmetic procedures, including Botox and fillers, then you will
have a record of what the patients looked like before the
procedures. This can be not only medico-legally useful but also
show patients how improved they are and encourage them to consider
more procedures.
If you need to schedule an extirpative procedure for a skin
cancer some weeks in the future, rather than trying to find the
original biopsy site from memory, or a hastily drawn diagram in the
chart, a photo will help you pinpoint it exactly. Sometimes
you or the patient may be concerned about a given lesion but not
enough to warrant a biopsy; the ability to compare the lesion now
with photos taken in the past may reassure you both or suggest that
a biopsy is indeed now necessary.
Some dermatologists have teaching collections of interesting
photos; digital photos can, with some forethought, be easier to
store, retrieve and even share with residents or
colleagues.
As with every therapy and procedure there are of course some
potential negative aspects. You have to buy a digital camera (see
below), and either learn how to use it or assign one of your staff
to do so. The photos will then need to be transferred to a computer
using a storage system that will enable you to easily retrieve them
in the future. In addition, there is always the risk that if you
take a picture of a potential skin cancer that someone in the
future might review your photo and say that given this picture you
should have biopsied it immediately rather than use the photo to
see if it has changed at a future date.
While there are a plethora of digi-cams available, I think
dermatologists should consider basically two types for office use:
"point and shoot" and D-SLRs (digital single lens reflex).
Don't worry about megapixels, CMOS or CCD chips, or chip size, as
any of the newer cameras will take adequate pictures for office and
teaching use. However, while almost all cameras have a "close-up"
function (usually indicated by a button with the outline of a tulip
on it), some are clearly better than others. Many dermatologists
use cameras from Sony, Canon, Nikon and Casio; as new ones are
coming out every 3 to 6 months if I recommend one or the other now,
it may be replaced by the time you read this. In general, top
of the line point-and-shoot cameras from any of these companies are
less than $500 (€370) and are excellent for both office and general
use. I am personally using a G9 by Canon but only because it also
takes "raw" images which are easier for me to work with in Adobe's
Photoshop; almost every other small camera defaults to "jpg" images
which are both compressed and "enhanced" by the computer program in
the camera. I also have a 5-year-old Sony T-1 which is also
excellent for office use.
Image stabilization is also a feature you may want to look for
in a pocket sized camera, as without practice, they can move as you
mash the shutter button. Another useful feature is "optical zoom";
digital zooms give impressive numbers but are basically worthless.
Another benefit of the smaller cameras is that they can be used
with derm-lights and even with microscopes without too much
difficulty. Aiming with the smaller cameras of course has to be
done by viewing the screen on the back of the camera because when
you get closer, what you see through range finder on top is not
what the lens is actually seeing. Another consideration is battery
type: many cameras require you to use their own rechargeable
batteries. If that is the case, buy two, as the one in the camera
will always be totally discharged just when you have to take an
important picture. A few cameras still use AA type batteries and
these are readily available no matter where you are.
For pictures with better lighting than either the room lights or
the tiny flash built into the point-and-shoot cameras you may want
to consider D-SLRs. While new ones are coming into the market at a
record pace, the established leaders are Canon and Nikon. Both
companies make excellent macro lens and I encourage you to purchase
a macro lens for office use. You will not need the top of the line
"heavy metal" cameras for excellent photos but you will need to
consider the size of the chip as cameras with less than 35 mm sized
chips will effectively multiply the focal length of the lens. For
example, if you have a chip that has a 1.6 multiplier factor, your
100 mm macro lens is now effectively 160 mm, which means you may
have to stand outside the exam room to get even an upper body
picture. In general, for all but the most expensive (full chip
sized) D-SLRs, consider a 60 mm lens.
Lighting is very important. How many times have you opened a
dermatology magazine and seen before and after photos that had
different lighting and even different colors? These photos are not
useful to say the least. While a dedicated room with carefully
placed lights and neutral color walls is ideal, most of us use
electronic flashes and if used with some practice can give
excellent repeatable quality. The flashes built into some D-SLRs
are useful for general photos but when you get very close they may
over light one part of the lesion and leave another part in the
dark. Small external flashes are inexpensive and can be either hand
held or placed to the side or above a camera, either wired or
wirelessly, with inexpensive supports. Both Canon and Nikon also
offer close-up flash units that sit in front of the lens and whose
lighting can be altered to be evenly distributed or slightly
stronger on one side than the other, offering some shadows and a
more 3 dimensional picture. This function is highly
recommended. Note that there are "ring flashes" for
point-and-shoot cameras: Marumi and Digi-Slave among others make
them. They are not as controllable but are inexpensive and may be
useful with some practice.
D-SLRs with macro lenses and external flashes are not small so
while you can potentially get better photos you (or your staff)
will have to retrieve the camera for each photo session; you would
do well not to simply leave it on a counter top as they can
occasionally fall or somehow disappear.
Note that there are "all in one" products by companies such as
Canfield and MoleMax that are complete systems for dermatological
photography and if you are interested you might want to investigate
them.
I encourage you all to at least purchase and use a small pocket
sized point-and-shoot camera but before you purchase one, try
taking a picture of a small area on your own arm and see if you are
happy with both the ease of use and quality of image.
Useful net sites:
http://www.emedicine.com/derm/topic618.htm
http://www.dpreview.com/
http://www.steves-digicams.com/hardware_reviews.html
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