Hi Leonid,
Problem #1 is metal. Silver robs gemstones of their color. Review
recent discussion on color of gold.
As I recall, you lost that one pretty conclusively.
I'm using a small tabletop lightbox with two compact fluorescent
bulbs(100W equivalent - 5000k Full spectrum white) on either side
of the box. I've experimented with all sorts of angles and
light-to-box distances. I've photoed in a room with and without
ambient daylight.
Problem #2 is the light box. I know it's been pushed like some
kind of panacea, but frankly it is the worst idea in photography,
except maybe shooting in complete dark.
You mean shooting in a blacked out studio, like most pros do? (The
ones with enough room, anyway.)
Light box is a 30% solution. Since most people photographing skills
are even less, a lot of them using it. However, photographing
gemstones require 100%, so light box does not work. It creates a
lot of diffused light which bounces of gemstones surface without
penetrating it. So you do not get internal reflections.
So, how exactly does a photon know it’s been through a diffuser, and
so should bounce off a stone without penetrating it as it normally
would? The mechanism of these genius photons intrigues me.
He’s half right, though: if you use just a diffuser, the lighting
will be pretty flat. (that’s the point of a diffuser in the first
place, and light boxes are just inside-out diffusers.) The reason
for using a light box is to control the reflections of the rest of
the room environment, so you don’t get all sorts of random room
stuff showing up in the reflections. Silver hollowware is infamous
for this. If you don’t want to use a light box, your other solution
is to shoot in a blacked out room, with enough space that nothing
else in the room is illuminated by your lights. Most of us don’t
have that kind of space, so we use light boxes.
(Light boxes give a flatter effect, as they’re white, rather than
the darker, more dramatic effect of a blacked out studio. (The
shadows are brighter, rather than pitch black.) But either one’s
lots better than having to retouch your couch out of the side of a
silver goblet.) My normal setup is two diffused 14" lights on either
side of a light box, with a 7" diffused light somewhere very close
to the camera lens axis, as a front-on highligher. That usually
works pretty well, or at least it’s a starting place. The 7" light
gives enough ‘direct’ light to keep the image from looking flat,
while the big diffused lights do most of the work.
As has been pointed out by others, if you want to get some sparkle
going, you need direct, focused light. I’ve been known to use
flashlights, or fiber-optic illuminators. (I even tried lasers on a
ruby once. Not such a good idea.)
The problem with teeny secondary lights is that they probably don’t
match the color balance of your main lights. It’s reasonably easy to
compensate for color shifts of the whole shoot, but if you’re
using lights with two different color temps, all sorts of really
nasty localized color shifts creep in.
I keep a small Gretag-Macbeth color card in my camera bag. It’s
about the size of a credit card. Chuck it down in the first shot in
a new setup. It’s got a whole bunch of ‘known’ color swatches that
will let you get your color balance and exposure dialed in properly.
(Looks like they don’t make the one I have any more. Closest I could
find was this one on amazon:
http://www.ganoksin.com/gnkurl/ep804w
It’s in a hardshell case, and is nicer than the one I have, if a tad
more expensive.)
One of my tricks for dealing with both color shifts, and
spotlighting stones is to remember that I’m shooting data, not film.
Take a nice overall shot of the piece, with the camera locked on
manual focus so nothing moves between exposures, and then take
another shot without moving anything with the stones picked out
with spotlights. Make sure you get color balance exposures for both
lighting setups. Then use photoshop to swap in the ‘hot’ stones from
the spotlit exposure into the diffused one. (You really want a
camera that can use a cable release.)
Another problem with sparkling stones is that you have two eyes, but
your camera only has one lens.
Your brain takes the images from both eyes, and synthesizes them
into one ‘whole’ image that you think you’re seeing. For most
things, it doesn’t matter, but for stones, you’re getting the
sparkle from both eyes, and they’re 3 inches apart. You physically
can’t get as much sparkle out of a single-lens setup as you can
from two eyes side-by-side. As an experiment, grab a CD, and look at
the rainbow side. Now close one eye, and watch what happens to the
rainbow. Close the other. Notice it shifts around? Notice that the
rainbow is wider with both eyes open than it is with one closed. Try
the same thing with a nice big sparkly stone. You’ll suddenly notice
that half the sparkle you’re seeing is coming from each eye, and
that neither one of them is getting anywhere close to all of it.
You simply can’t get the whole effect that you think you’re seeing
without using photoshop to simulate the merging that your brain is
doing on the fly. There are techniques that let you shoot for that
effect, and then do a photoshop merge, but they’re pretty advanced
PS magic.
12 megapixel sound a lot, but for jewellery photography quality of
light sensor counts for more than quantity of pixels. You need
camera with CMOS sensor and ability to dial high ISO. High ISO
produces a lot of noise, which has to be corrected. That means
shooting in raw format.
He’s not totally wrong. I shot professionally for years with an 8MP
camera, but it was a DSLR, with a real sensor, and good lenses. It
held its own for about 5 years before I had to replace it, simply
because of the quality sensor and optics. On the other hand, I’ve
gotten some surprisingly good ‘off the cuff’ shots with an 8MP
compact camera.
That said, I have no idea why exactly he thinks high ISO is a good
thing. It makes the exposures noisy as hell. If you’re shooting
seriously, you’re already on a tripod, so there’s no reason not to
keep it down to ISO 100, and let it take however long it takes to
get a nice clean image.
If you have some way to rig it up, shooting tethered makes life a
lot easier. That way you can evaluate your exposure, focus, depth of
field & etc, immediately, on a nice big screen. And yes, if you’re
serious, you’re shooing in raw. It lets you tweak the image without
changing the original data, so you can always go back if you don’t
like the ‘fixed’ version.
Bridge CS6 raw utility does great job in eliminating color noise.
Quality of lenses is a huge factor as well, probably even more
important than camera itself. But one cannot be separated from
another.
I tend not to use bridge for raw processing, I prefer lightroom. It
makes bulk file handling, keywording and archive management easier
than Bridge does. (It’s also cheaper, if you don’t have the full CS
package.)
He’s right about the lenses: if your glass is crap, there’s an
ultimate limit to what you can achieve, regardless of other factors.
The point-and-shoots are shockingly good these days, and may
possibly be ‘good enough’ for anybody but serious image snobs, (like
me) but they’re never going to be as good as a full-on D or L series
macro lens. On the other hand, the small size of their lenses gives
them amazing macro capability, and depth of field in macro mode. So
there are positives to them as well.
The real question is this: what’s the purpose of these photos?
Getting your stuff into shows, or publications? In that case, use
what you’ve got, and figure out how to get the most out of it. (I
suggest workshops.) If people are paying you for the images, you
need to get real gear, and learn to use it.
Both are required. Consider using polarized filter. LIght
reflecting from metal surfaces always becomes polarized. Filtering
it may help with gemstone appearance. But understand that cheap
filters do more harm than good.
I do shoot with polarizers, both on the lens, and on the lights.
They let me control the reflections very precisely, but they also do
weird things to stones, and frequently kill surface reflections on
stones completely. (To the point where I have to grab a ‘reflection’
shot to use to put the reflections back on the surfaces of the
stones.) Nothing looks weirder than a cab with no shine on it
anywhere, or a brilliant. that isn’t. They also boost the apparent
saturation of most transparent colored stones. Which may, or may not
be an issue, depending on the purpose intended for the image.
Souping the stones on a shoot that’s going to be used as a magazine
PR image of a line of jewelry is one thing. Souping the stones on a
sales image of a particular piece of jewelry is another. (In the
first case, it’s a generic image illustrating an entire line,
printed in a way that couldn’t hold the real colors anyway, rather
than the second case in which the image needs to be an accurate
representation of one single piece.)
For whatever that all was worth.
Regards,
Brian