The Art of Photographing Gems

by

Kallie Moore


http://www.emporia.edu/earthsci/amber/go340/students/moore


Lab grown crystal from Germany.
Photograph by Kallie Moore, 04/2006

This webpage project was created for a gemstones and gemology course in the 2006 spring semester at Emporia State University. The assignment was to learn webpage creation, as well as present a summary of my knowledge regarding the art of photographing gems.
In order to understand gemology, a background in traditional mineralogy (see www.emporia.edu/earthsci/amber/go336) is important. For more information email KalicoFlowers@yahoo.com

Table of Contents

Introduction

Gemstones are valued for their beauty, durability, and rarity. Because of these reasons gemstones are photographed. Photographing gems serves two purposes: 1) good scientific illustration, the specimen must be depicted fully and accurately; 2) fine-art feeling of aesthetic quality, the photograph comes alive with sparkle and depth (Wilson, 2005). Master gem and mineral photographers use many techniques and thought processes that can be learned and then adapted to one's own style and ability. Many different aspects go into gem photography: specimen choice, cameras, lighting, background, and equipment.

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Aesthetic & Specimen Considerations


Drusy Azurite (blue) on Malachite (green).
Azurite is a problematic mineral because of its color, even more so by the drusy habit.
Photograph by Kallie Moore 04/2006

There are many considerations in choosing a specimen to be photographed. Generally, the qualities that make a specimen a good one to begin with also make it a good photographic subject (Scovil, 1996). These qualities are the color, the absences of flaws, the arrangement of crystals, and the proportions. Rarity and size also help make a specimen more valuable but it doesn't contribute to the making of a good photograph. There are some types of specimens to avoid when photographing. Tightly packed crystals are hard to define in a photograph. Also specimens with a drusy habit should be avoided because the crystals come out "as a mass of indefinable sparkles" (Scovil, 1996). Some minerals are just not photogenic. Azurite and dioptase are hard to photograph because of their intense color. Occasionally there will be a specimen color that is beyond the sensitivity of the film and it will not be able to record the color accurately. These problem minerals are blue fluorite (turns grayish purple), emerald (wrong shade of green), and blue barites from Colorado (also turn grayish). Lustrous black minerals can be a challenge because of their high contrast (Scovil, 1996).

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Equipment


My 35mm Single Lens Reflex (SLR) camera.
Photograph by Kallie Moore 04/2006

The most important part of photography is the camera. The two types of 35mm cameras used in gemstone and mineral photography are the single lens reflex (SLR) and the rangefinder. The SLR has one lens that is used as a viewfinder and for taking the photograph. A rangefinder camera has a lens and a separate viewfinder that is above or to the side of the lens. This limits how close you can get to the specimen and the subject still be in focus. At short distances the rangefinder and the lens are looking at different subjects. This is called the parallax error (Scovil, 1996). Rangefinders are very similar to "point-and-click" cameras available today. These cameras tend to do the work for you but have limited zoom capability and fixed lens. Most gem photographers recommend a 35mm SLR over a rangefinder. Medium-and large-format cameras are also available. Medium-format cameras still use a roll of film like a 35mm does but come in many shapes, sizes, and multiple lens. These cameras are versatile and smaller than large-format cameras. Large-format cameras hold two sheets of film. The film has a dark side that protects the film from light until the proper time (Scovil, 1996). Focusing a large-format camera is done by movement of the standards (were the lens and shutter are housed) because the lenses do not have a focusing mechanism. The advantage to view cameras is the larger film size that range from 2 1/4 X 2 1/4 inches to over 16 X 20 inches. The large film size allows for more detail in a subject to be retained (Scovil, 1996).
For a 35mm camera the standard lens size is a 50mm. This lens has a focusing distance of about 18 inches. For gem photography the photographer will need to be much closer to the subject. A macro lens would be the best choice for close up work. They are designed to focus much closer to the subject and are able to get a "life-sized" image (Scovil, 1996). The optics are also better than a 50mm lens and will give sharper photographs. There are two kinds of macro lenses: lenses with about 50mm and lenses with about 100mm in focal length. Both of these types have their pros and cons. The 100mm lenses have a more working distance, so the photographer does not get in to way of the lights. It also has a better perspective and representation of the subject. Those lenses that are about 50mm have higher magnification and better depth-of-field compared to the 100mm lens (Scovil, 1996). These lenses tend to be a little expensive, $130-$470 +, but they will save time and space in an equipment bag. For medium- and large-format cameras, Jeff Scovil (1996) recommended quality lenses from Schneider, Zeiss, Rodenstock, and Nikkor.
Choosing a film to use depends on the specimen and lighting, as well as what the photograph is going to be used for. The usual choice for gem photography is color film because of the "incredible range of colors found in the mineral kingdom" (Scovil, 1996). Photographers that have access to a personal dark room prefer black and white film. The film forces the photographer to work with line, form, and texture plus the photographer has more control over the results. Film is measured by its sensitivity to light known as film speed. The higher the film speed number is the more sensitive to light it is. Faster film is more sensitive to light than a slower film. Film speed is based on the ISO (International Organization for Standardization). This system is an arithmetic system, where each speed is either twice as fast as the previous one, or exactly half as fast as the next one (theImage.com, 2005). There is also the ASA (American Standard Association) and the DIN (Deutsche Industrie Normen) but these are not used as often as ISO. Although low numbered ISO film is slower and less sensitive to light, they have a finer grain and better color rendition. This is important if large prints are going to be made from the photograph and a good color rendition is needed to accurately represent a specimen (Scovil, 1996).
Backgrounds help control the light of a photograph. They can provide contrast in color and texture to support the specimen. One of the easiest backgrounds to use is colored paper. A sheet of paper is set up to curve behind the subject and creates a seamless background. Color-Aid and Chroma-Rama are the best kinds of paper to use in photography. They have a matte surface with the color silk-screened on one side only (Scovil, 1996). Care must be taken with these papers because creases will show up in a photograph and the color can be scratched off. White translucent Plexiglas can also be used for a neutral background. It can also be partially shaded to produce a tonal gradation. White/grey Plexiglas doesn't introduce any "extraneous" color through the back of a gem or any strange colors onto the front of the gem (Wilson, 2005). The shadows that are produced by the specimen are diffused on the Plexiglas and are not very distracting. There are many different lighting effects that can be produced when working with Plexiglas just by using reflection and black paper (Scovil, 1996).

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Lighting Sources & Techniques


Bi-colored Mexican garnet with isometric crystal system visible.
Photograph by Kallie Moore 04/2006

"Taking pictures of a lustrous, multi-faced crystal, as Joel Arem has said, can be compared to taking a picture of a pile of broken mirrors.
The crystal is going to show you, in little bits and pieces, what it is seeing around the room" (Wilson, 2005).

There are two different light sources one can use for gem photography: Sunlight and Artificial sources. The different types of light sources emit light with varying color temperature. The variation is measured in Kelvins (K) and this scale rates light. Film color temperature must match the light source for accurate color rendition (Scovil, 1996). Sunlight is the most obvious light source and it is free. There are some problems with sunlight, as the day progresses the color temperature of the light changes. Color temperature of sunlight can also change by how cloudy, foggy, or smoggy it is outside. These reasons make it hard to maintain a constant and accurate color rendition using sunlight. Direct sunlight can be too harsh, producing deep shadows and high contrast. Artificial light is a way to get a constant light and color temperature. One of the most popular artificial light source available is the tungsten bulb. A common problem with tungsten bulbs is that their color temperature changes when they get older. This means they need to be changed before they get old (roughly every 3 hours for a 500 watt bulb). Another type of bulb that can be used is a quartz halogen. These bulbs maintain their color temperature throughout its life (Scovil, 1996). An electronic flash can also be used. Flashes produce a short burst of intense light depending on the setting and come in all shapes and sizes (Scovil, 1996).

According to Wilson (2005), there are four different kinds of light that a photographer must deal with: 1) Light reflected off the surface, 2) Light that is reflected from the internal structure or the "body color" of the gem, 3) Light that is introduced from the back of the gem, and 4) Light that enters the front, bounces of a back face and comes through the front again . Wilson suggested that all of these different types of light need to be balanced in order to accurately represent the specimen. One of the major considerations in working with light and gemstones is to control or accentuate reflections. Wilson detailed different types of reflections and four are given below.

In addition to the considerations of reflections, special attention should be paid to backlighting gemstones. There are 5 methods of backlighting. If the background shows through the specimen it shouldn't be any color other than white or grey. Colored backgrounds will add color to the body of the specimen and could cause confusion to the viewer.

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References

Return to GO 340 student webpages.

Date the webpage was created 29 April, 2006; last update 29 April, 2006. © 2006 Kallie Moore. All rights reserved.