Tue, 09 Jun 2009

The Camera May Not Lie – But it Tells Different Truths

I have been in the jewelry business since 1970 when I bought my first gemstone for a girlfriend in Rio de Janeiro, Brazil.
Within days I was buying & selling gems and my lifelong love affair
and study of gemology was started. I graduated from the Gemological
Institute of America in 1975, and have been a proud member of the trade
ever since.

 

The
purpose of this article is to show you how cameras can be a useful
tool, but while they may not lie, they might often tell you different
truths, and thus should not be used as the only selection tool in
choosing your diamond or other gemstones.

 

The
more I photograph diamonds, the more that I realize different
equipment, lighting and camera settings can make the same gem look
different. Unlike ASET® and Ideal-Scope® images, which are often
standardized to allow photographic comparisons, “real world” photos and
videos have no such standardization.
Consumers hoping to make intelligent buying decisions should be made
aware of the advantages and limitations of non-standardized photos and
videos of diamonds.  In this article I will post several examples to illustrate this. 

 

Using the camera as a tool – not an absolute

 

Please
take a moment to watch this video as an introduction. It is just over 2
minutes long and is very illustrative of the problems that can be seen
with cameras.

 

 

 

 

 

I
find it incredibly interesting that the same diamond can look so
different, even when the same camera is used as in the “second and
third diamonds” in that video, but especially when different cameras
are used.  The “second and third diamonds” were
shot through the same camera, but using different software with
startlingly different results.

 

The above video was taken of the same diamond; a 0.72ct D-VS1.  The first camera is a Bodelin Proscope that I have used for a couple of years.  It is actually the same camera that is used by many CSI units across the country (Yes, Virginia, there really is a Santa Claus – just like there are REAL CSI units – not just those seen on television…).  The second camera is a Dinolite 411T which is marketed through www.thelittlecameras.com.  It
is a fabulous little camera for still and video images and I include
the link for any one who needs one, although I really hope my
competitors do not read this article…

 

 

I
am also going to include several shots taken with still cameras; one
that I have used for years, and one that I am just now beginning to
understand.  The first is the Panasonic KR222;
basically a hospital hallway surveillance camera that I have had slaved
to my computer for seven or eight years through a flashbus twain
interface that I will never again have to mess with.

 

The
second is my new Nikon D-300 with 105mm telephoto lens with macro
filter that is now slaved to my computer via Nikon Camera Control Pro 2.  It
allows me to set up a diamond in my light box and take various
exposures without having to move my diamond at all or touch the camera.  I can even focus through the computer so that no camera movement is introduced at any point in the photography.

 

Four Photos

 

I am going to start by sharing with you four photos of one diamond, a 1.77ct M-SI2 round brilliant.  Here
is the first, from the HPDiamonds.com website, in which this loupe
photo shows with extreme prejudice all of the clarity characteristics
in this diamond.  It actually makes the diamond look horrible!

 

 

 

To look at this photo, you might think the diamond was a middle-to-low I1, yet is it not!  It
is the loupe photo, expanded to allow you to see all that is inside the
diamond, much more than you will ever see with the unaided eye, and the
camera and method of photography exaggerate the inclusions.

 

The next photo is taken with my old Panasonic camera.

 

 

The
diamond is still pretty lifeless and, although not in black and white,
it certainly does not show the colors I see which are rampant in the
diamond.  More on that later, it was referred to in the video above, but we will go into it at length in a short while.  Oh, and yes, the inclusions are still exaggerated; it still looks like an I1 in the magnified photo.

 

These
last two pictures I will show you right now for this diamond were taken
with my Nikon D-300 and they actually allows me to share some of the beauty of this diamond.  The one on the left was taken with an F/3.5 F/stop and the one on the right with F/25.

 

 

Which of these diamonds would excite you if you found them on four different websites?

 

Over
the past several weeks, I have shown the last two photos to several
people in my office and asked them which one they liked better.  Several
preferred the one on the left for its bright “flame of fire” coming
from the lower pavilion main facet, others preferred the one on the
right, it just seemed to have more “character and flashes of color” and
was not as yellowish.

 

So, which of these photos is an attractive photo?  Which one is an accurate photos?  Which can we use to select our diamonds? 

 

All of them?  None of them?  Oh, and WHY DO THEY ALL LOOK SO DIFFERENT???

 

Technical Differences

 

Okay,
here is where the science stuff comes in and since I am not a
scientist, I will speak in layman’s terms about dispersion and how it
is observed by the human eye.

 

When light enters an optically dense medium, such as water or a diamond, it bends as shown in this familiar drawing of a prism.

 

 

Here is the tricky part.  As the light enters the prism (optically dense medium) it begins to disperse.  As
it leaves the prism, it disperses even further, making the lovely
rainbow on the walls that we saw as kids when we played with prisms. 

 

As
you can imagine, when a wave of white light enters into a diamond, it
has many more options to be lead astray and can be broken in to tens of
thousands of rays within the diamond.  In fact,
it is this dispersion within the diamond that makes all the virtual
facets possible (virtual facets are like looking into a mirror at the
barbershop – does anyone still go to the barbershop? – when there is
another mirror behind you and it seems like there are thousands of you
each smaller than the last until you fade into infinity getting smaller
and smaller). From these tens of thousands of virtual facets, the light
is reflected until it is refracted from the diamond and resumes its
journey, some of it as white light, and some of it as dispersion as
shown above.

 

Now enter in the eye, more importantly the pupil of the eye, or the aperture of the camera.

 

 

If,
at the pupil of the eye, the dispersed area of the ray of light is
wider than the pupil, the light will be perceived of as colored light,
or dispersion.  With the prism this is easy, as
the light is bent very strongly both going in and coming out of the
prism, and with a minimum of interference.  It is a wide ray, and even at the edge of the prism it would likely be visible should you put your eye up to it.

 

However,
if at the pupil of the eye, or the aperture of the camera, the ray of
dispersed light is shorter than the width of the pupil of the eye, then
the light is recombined and perceived of as white light, which is
actually light that is made up of all of the colors together.

 

This
picture of the relative size of two different f/stops will help
understand why different cameras can show such different views of the
same diamond. The aperture on your eye opens up in the dark to let more
light in.  This is why you will normally see less dispersion at night.  With a camera we can use a smaller aperture and a longer shutter speed to get the right amount of light for a good photo.  We can also adjust depth of field in this way to allow more of the diamond or jewelry to be in focus.

 

 

Since
a diamond is usually a fairly small object in mm size, and they are
normally looked at from fairly close distances, and since the
dispersion of the ray going into the diamond will create literally tens
of thousands of virtual facets, most of which are too small to be
observable  to the unaided eye, it is easy to
understand that many of the dispersive rays will be fairly narrow by
the time the reach either the aperture of the camera or the pupil of
the eye and this light may well be observed as white light, depending on  the width of the pupil of the eye, or the aperture of the camera.

 

Thus,
if you look back to the picture I took above with the f/3 f/stop, the
aperture was large and small dispersive events were perceived by the
camera as white light.  The huge event off one of
the lower pavilion mains was seen in this picture as a wonderful yellow
and orange flair of dispersion off one of the arrow shafts and orange
and white off of the corresponding arrow head.

 

This
is proof by the way that the diamond was not perfectly perpendicular to
the camera, as normally that facet would be part of the obstruction
pattern that is observed in a hearts and arrows viewer.  Part
of the magic though is that as the diamond is tilted one way or
another, facets that are off light up, and facets that are on become
obstructed, which is what gives us the incredible scintillation that we
treasure in a diamond.

 

Looking
again at the photo beside that one that was taken with an f/stop of
f/25 you will see a myriad of smaller dispersion events with more
colors, and sadly, the wonderful yellow flair has for some reason
disappeared.  Perhaps the part that hit the wider
aperture is now outside the much smaller opening of the f/25. I do not
know the answer to this, perhaps also the camera or the stone moved a
fraction of a mm due to vibration, I do not have the equipment or the
training to measure or answer that question.

 

I
do know that I took several pictures before getting the one with the
flash of yellow that I could see at all times through the view finder.  It was only when I opened it up to the f/3 that the flash remained.

 

Composite

 

Just
for fun, here is a composite photo of the same diamond showing a total
of six different shots, including one from my old camera.  Each and every photo has a different flavor, and in the five taken with my D-300 only the aperture was changed.

 

 

Now we have a better understanding of why what we see in the camera is not necessarily what we see with our eyes.  In
my KR222 the color of the diamond barely shows, which is much as I see
it with my eye, but it fails to capture the dispersion I see with my
eye. 

 

I am 62 years old as I write this, and will see color differently than someone who is younger.  Where I once scored 98% on my Munsel color test I would likely score lower now, and lower again when I reach 80.

 

As is clearly demonstrated above, my camera has trouble capturing color perfectly too.  Perhaps a professional could get perfect color rendition on the pictures, I do not know. 

 

What
I do know is that clearly the camera is a tool that can allow me to
show you much about the diamond, whether it be from a moving picture
such as the video shown above, or from a still camera.

 

With
the stills we can go for a look inside the gem, as with our loupe
photos that we provide with each diamond, or with a glamour shot that
shares some of the beauty of the diamond with the viewer.

 

I am including another picture for illustrations sake; you decide what is important to you in a photo.  The center stone is a D color, the sides are F.  I do not believe it is possible to accurately tell the color in the photos.

 

 

If
asked to choose the most attractive photo three people might choose
differently, and these are relatively close. Darkness, brightness,
color, dispersion, sparkle… All depend on the equipment, lighting and
settings.

 

Be Aware

 

Some
sellers will have better cameras and better skills than some other
sellers. Others may have lesser cameras and skills, but their diamonds
may be just as beautiful.

 

Something
I have not even touched on in this article is the use of supplemental
enhancement devices like “star” filters which unnaturally enhance a
diamond’s sparkle in photos – or adjustments made in a photo editing
program. One only has to look on eBay to find examples of photos
so-enhanced that they are probably not accurately depicting the
gemstone in any environment. I personally will not use such
enhancements but they are out there and in-use by some advertisers and
sellers.

 

In
closing, I would simply counsel you to remember that “real-world”
photos and videos are useful, but not absolute as purchase-decision
makers. They can to help you decide which diamonds you may wish to see
live with your eyes, but it is YOUR eyes and not the camera’s that must
be happy when the deal is done.  To that end the camera may never lie, but it tells different truths.

 

Wink Jones

Graduate Gemologist

High Performance Diamonds

 

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