“Bolivian relicario of the Coronation of Our Lady of Copacabana, painted in oils on an oyster shell that has been surrounded in chased silver with a chased and engraved finial. A thin border of reverse painting on glass frames the shell. 10.6 x 5.5 x 3 cm.” Right: three-quarter view. The frontal image was used with my permission as the cover photograph in author Martha J. Egan’s excellent book, Relicarios --- Devotional Miniatures from the Americas.
One of the true joys of including photography of art in my commercial assignment photography is the privilege of seeing magnificent art, accepting the challenge of understanding its conception and design, then employing a combination of various techniques to capture these faithfully in the photographic medium. The 100 year-old miniature relicario of “Our Lady of Copacabana” pictured above is an example that is discussed in this article so that readers will understand the challenges and systematic considerations that are made in order to make these photographs. First, however, general background information must be covered. Other types of miniature art such as translucent or transparent glass, fabric and/or paper assemblages require different treatment. These will be discussed in detail in other blog articles.
This article primarily addresses photography of two-dimensional or nearly two-dimensional opaque miniature art and art objects. Photography of relicarios is discussed primarily because they offer several photographic challenges that are often faced when photographing miniature art. Close-up photography of industrial and/or scientific subjects often requires different techniques and very different considerations, many of which are not common to photography of small art objects. The illustrations and examples in this article are discussed in order to review several types of technical challenges that are often faced in photographing these types of miniature art: (1) miniature paintings, (2) miniature paintings under glass that cannot be removed, (3) miniature paintings under glass with imperfections, (4) miniature paintings under glass with highly polished and ornate jewelry-type cases, and (5) miniature paintings under irregular (curved or faceted) glass.
General Technical Challenges…
The goal of photography of miniature art is to produce accurate representation of the physical object, its colors, design, textures, and form. It is not to produce “artful” photographs of art. Also, the safety of the art must always be considered when photographing it. This goes far beyond careful handling of the art and must include careful employment of techniques which do not place the art at risk. One must never lose sight of both of these concepts when photographing art.
The primary challenges are technical in nature: (1) the ability to compose and focus on small objects, (2) the ability to properly light small objects, (3) isolating the art objects from surrounding backgrounds, colors, textures, etc. that detract from appreciation of the overall photographic reproduction of the art itself, (4) determining the proper exposure, (5) avoiding image degrading camera and/or subject movement during exposures, and (6) maintaining depth of focus so that all parts of the art are sharp. Most of these challenges --- and their solutions --- are interrelated.
Lens Choices and Camera Types…
Many of the technical challenges of photographing large art are shared with photography of miniature art. However, the challenges inherent in photographing miniature art are made more difficult due to the short distances between the camera lens and the art itself. These distances are usually so close that proper lighting of the subject is made difficult. It is not unusual for the camera to “get in the way” of the lights and/or light modifying tools. For example, the equipment set-ups that I used when photographing these relicarios obscured seeing the relicarios from every perspective except the viewfinder of the camera – which was awkward to see through due to the necessary placement of the lighting equipment!
The focal length of the lens used in photographing miniature art greatly impacts related technical challenges in this type of photography. In most instances use of a short telephoto lens is recommended to increase the working camera to subject distance. Something on the order of 2-2.5 power magnification is adequate. For 35mm film cameras this would require a 100-135mm lens. For most digital “35mm” cameras (which have a smaller sensor area) the equivalent is a 70-85mm focal length lens. In all cases of photography of miniature art, whatever focal length lens that is used, it must have the capability of close focusing. Cameras with interchangeable lens capability are the most useful. They allow the use of extension tubes. These extend the lens from the film or digital capture plane. This shifts the lens’ focusing range so that the camera can focus much closer. Macro lenses have longer built-in helical focusing coils which enable them to focus from very close to infinity. Many of these macro lenses also can be used with extension tubes to achieve extremely close focus on very small objects. Macro lenses produce superior images of flat art at close ranges because they are designed to do so. However, most modern lenses when used with extension tubes produce very high quality images of miniature art when smaller apertures are used. This is true because when smaller apertures are used only the flattest (center) portion of the lens is used. This is the portion of the lens that is easiest to polish to close tolerances during its manufacture.
A few words are necessary here regarding types of cameras. Most people using 35mm film cameras will use single lens reflex (SLR) cameras. These allow the camera operator to see essentially what the lens is “seeing”. Most modern digital cameras operate more or less the same way in that what is shown on the viewing screen is the image that the cameras will capture. Medium to higher priced digital SLRs facilitate close up photography and usually offer more useful features than less expensive non-DSLRs. Some photographers may want to use non-SLR camera types such as medium format, twin lens reflex film cameras. Parallax problems exist with this type of camera because the viewing lens is not the same as the lens which captures the image. While this is not an issue when such cameras are focused at distant scenes, it is a very significant problem in close up photography. Therefore twin lens reflex cameras are not recommended for photography of miniature art.
The Need for a Sturdy Camera Support…
Another technical challenge exists when photographing miniature art: the risk of obtaining un-sharp images due to camera movement. As images are magnified either by close focusing a camera lens or by using telephoto lenses, the risk of making the photographs un-sharp due to camera movement increases. This risk is inevitable because as one increases image magnification, one also increases any image blurring movement that may occur during an exposure. Consequently, a sturdy camera support is essential. This support has an additional benefit—a good camera support aids critical composition. As one focuses on small objects, even minimal camera movement has a significant effect on composition. The most convenient and safest method of photographing miniature two-dimensional art is to have a camera mount based upon the camera looking down at a static subject stage or platform. This eliminates the need to mount often delicate miniature art objects on vertical surfaces. While vertical mounting of miniature art can be done in a number of ways, the risk of damage to the object in this manner always increases. This emphasizes an extremely important point in photographing any art: every effort must be made to protect the art being photographed—there are no exceptions. No shortcuts in technique or in planning should be taken which might raise the risk of damaging the art.
Vertical mounting of miniatures for photography also presents another problem: how can one best get a sturdy camera mount close to the subject? A traditional tripod’s legs must be extended. This requires that the tripod’s camera mount be some distance from the vertical surface where the miniature is mounted. This in turn determines how close one can focus and or compose any given camera/lens combination. Therefore, vertical mounting of a miniature for photo documentation may at first seem simpler, whereas it actually creates more technical challenges that must be solved. A simple diagram of a typical vertical copy stand is shown below. Commercially available copy stands can be purchased new or used. Very good stands can also be designed and made from quality lumber with a little ingenuity. An Internet search can produce plans for such home made copy stands that can be made by people with limited woodworking experience and limited access to woodworking power equipment.
Lenses and Depth of Focus…
Another factor that affects image sharpness when photographing miniature art is decreased depth of field (depth of focus). This decrease is exacerbated with the recommended use of short telephoto lenses. Such lenses are recommended as necessary to increase working distances between lenses and camera subjects in order to facilitate lighting of the miniature art as well as to render the art without distortion. This decrease in depth of focus can be overcome to an acceptable level by using smaller lens apertures. At any given distance between subject and camera, and when using any given focal length lens, smaller apertures result in greater depth of field (focus).
Greater useful depth of focus can be obtained by employing a technique of focusing not on the front surface of an object, but by focusing approximately on a point that is 1/3 in toward the depth or thickness of the art. This is called focusing on the hyper focal length distance. This is especially advantageous due to the limited depth of focus in miniature art photography. This technique is useful because the depth of focus at any given aperture with any given focal length lens, and at any given focusing distance is not equally divided between the front and rear of the focusing point. Rather, at any given focusing point the depth of focus produced by a lens’ aperture setting falls approximately 1/3 in front and 2/3 behind the focusing point.
It should be noted that image quality can be degraded by use of extremely small apertures. Such image degradation usually only occurs when one uses a large format view camera and with lenses which have extremely tiny apertures such as f 45 or f 64. In such instances overall depth of focus is deemed more important than critical sharpness. For most photographers who use small format 35mm film cameras or most digital cameras, this is not a matter of concern.
Minimizing Camera Movement During Exposures…
When using constant light as a source for subject illumination smaller lens apertures require exposure compensation through longer exposure times. This fact alone emphasizes the critical need for a sturdy camera mount and a stationary subject. Use of an inexpensive cable release which screws into the shutter releases of most cameras is highly recommended to minimize the chance of unwanted, induced camera movement at the time of the exposure. Some cameras, whether film or digital, may require an electronic cable release which triggers the shutter. This functions in the same manner and serves to isolate potential unwanted induced camera movement. Still other cameras have infrared remote triggering devices that enable the photographer to make exposures without touching the camera.
Light Sources: Pros and Cons of Constant vs. Electronic Light Illumination…
Another means of illumination, electronic flash, provides a better source for illuminating miniature art for its photography, and, at the same time, solves several problems that exist when using constant light sources. Advantages of electronic flash equipment include the following:
- The duration of the electronic flash is much more brief than most conventional shutters. The brief flash duration effectively serves as the working shutter speed and thus “freezes” the image, so to speak, rendering extremely sharp subjects without fear of motion induced image blur.
- Electronic flash enables placement of the flash heads farther from the subject so that the light striking the art can be better controlled and modified to suit the needs of any particular subject. Once the quality of illumination has been achieved by careful positioning of the electronic flash heads, if a greater volume of light is required in order to be able to use a smaller aperture so that more depth of focus can be achieved, one need only add more power to the flash heads in order to gain the additional volume of light required. With constant light sources, one must move the physical position of each light used closer to the subject to increase the volume of light reaching the subject. In many instances this is difficult, if not impossible or undesirable. One example would be moving 500 watt quartz light sources from 4 feet away to 2 feet away from a subject in order to gain just one more f-stop of light volume (for more depth of focus). At a distance of 4 feet the 900 degree Fahrenheit surface temperature of the bulbs of these lights produce a great deal of heat and thus pose significant risk to the photographer and to the art being photographed. Moving these constant light sources as close as 2 feet away from a subject may be possible, but it is certainly never advisable. In this example, if electronic flash is used as a light source, the flash heads would remain at 4 feet and the photographer would simply dial in an increase of power to the flash heads of 100% to achieve the additional volume of light needed to gain one smaller f-stop for greater depth of field. Moving constant light sources in closer to a subject in order to achieve a great volume of light on the subject also presents another problem: it changes the quality of the light striking the subject.
- By being able to place the electronic flash light sources farther from the art, photographic lighting is made easier and the art itself is handled in a far safer manner. This additional working distance between the lights and the subject being photographed allows the use of multiple types of light modifiers. These modifiers more often than not are scrims (surfaces which diffuse directed light through them), gobos (surfaces which block light), cookies (surfaces which break up direct light), snoots (tubes which are attached to the front of light sources in order to restrict the width of the light beams, “honeycomb” grid spots (as their name implies, these are constructed as honeycombs with various densities of holes, the greater the density of holes the more restricted the light is as these are placed in holders in front of light sources), focusing spots (these are light sources which employ optical focusing mechanisms to concentrate light beams), polarizing gel filters (large, heat resistant gel filters which polarize light passing through them so that glare [specular highlights] can be eliminated from flat and some curved surfaces when cross polarizing techniques are used—this technique is described in detail in my article “Demystifying Photography of Two Dimensional Art”), or reflectors (surfaces which reflect light directed upon them). There are many types of reflectors. Some may be highly polished such as acrylic or glass mirrors, some dull gray or white or even gold colored. In some instances crumpled aluminum foil placed over a rigid surface such as foam core may modify the light properly for photography of some miniature art. Depending upon the nature of the miniature art being photographed one or more of these light modifiers may be required.
- Although one would think that using bright quartz lights close to delicate miniature art would provide ample light to enable fast shutter speeds and small apertures, often this is not the case. Even small studio electronic flash can produce far more illumination, albeit very briefly, than that produced by high wattage quartz lights.
Unfortunately, the type of studio electronic flash equipment needed and its ancillary light modifier attachments are rather expensive. Nevertheless, photography of miniature art often requires use of this type of equipment in order to achieve excellent photographic representation of the art. Built-in, on camera electronic flash are useless in most types of photography. This is especially true in the photography of both 2-D and 3-D art. Such flashes produce harsh, flat, frontal directional light from near the lens axis. This results in hot spots (specular highlights) and the worst possible misrepresentation of the art. Think about it: these small flash units produce the type of unnatural light that one associates with, say, a prison spotlight!
Light Modifiers: Types and Why We Need Them…
If the miniature 2-D art to be photographed is a painting, (oil, pastel, pen and ink, etc.) on a non polished, opaque background, without a glass cover, without use of metal tinted colors, and without an integral frame, then one can use cross polarized light sources and an optically ground polarizing filter in front of the camera lens as is described in my article “Demystifying Photography of Two Dimensional Art”. One need only to carefully compensate for the “bellows extension” when determining the proper exposure. This is described in detail in the above mentioned article.
However, in photographing the relicario miniature art included in this article other techniques were necessary. This is because of the glass coverings, the ornate polished metal case, and the slightly 3-dimensional design of the religious art sample “Our Lady of Copacabana” relicario pictured at the beginning of this article. Use of collimated light sources in a traditional flat art lighting setup with these relicario art objects would result in harsh specular highlights in both the art and in the polished metal cases and probably specular highlights on the glass coverings. In other words, terrible photographic misrepresentations of the art would have been the result of use of these techniques.
An entirely different technique was required. Whenever polished metal surfaces are photographed one must have very large, neutral reflective surfaces and a very large diffused, main light source. The “Copacabana” relicario is only 10.6 cm high (4.17 inches). The diffused “soft box” light source (with a studio flash head inside it with opaque side panels and a front surface diffusing material) that was used as the main light to make these images is 91.5 x 122 cm (3 x 4 feet) and was placed at a critical angle a few inches to the side and below and above the relicario. Set opposite it and around it were “facet-type” reflector panels of pieces of near white foam core. These served to bounce light back along the edges of the relicario in order to separate it from the black velvet background that was approximately 15 cm (6 inches) below and behind the relicario. Had these panels not been placed the polished silver edges of the relicario would have done what all polished metal surfaces do when placed near black – they would have reflected black velvet and thus would have “disappeared” against the black velvet background. In effect, the reflective panels and large diffused light source illuminated the front and defined the edges of the relicario.
The support of this particular delicate relicario had to be modified. Normally a rigid support such as an acrylic block by itself would be used. However, this relicario has an eggshell-thin, curved back silver case with an even thinner interior piece of oyster pearl with its painted surface. One does not press anything against its delicate case. Therefore I used synthetic based modeling clay on the top of the rigid support acrylic cube. Rather than press the delicate relicario into the clay to create a form-fitted cradle, I used an inexpensive ceramic egg from a hobby shop to make an approximate indentation for the relicario’s cradle. This procedure enabled me to have a form-fitted cradle without putting any pressure on this delicate relicario. This ceramic egg “stand-in” was used twice to make separate customized indentations in the synthetic modeling clay, one for the frontal view and a second shaped indentation to better support the relicario in the three-quarter view that was made. Synthetic clay was used so as not to leave any residue on the silver case.
The images were made on professional transparency film with a medium format (6x6cm) Hasselblad camera using a 150mm lens and extension tubes to enable close focusing. The 150 mm focal length lens achieves about a 2X magnification on this format. Due to the lighter values of the reflective polished silver compared to the delicate colors of painted figure within the relicario’s interior, the exposure had to be exact. In order to insure that the chosen exposure showed the silver as looking like it does in real life, the exposure was determined by “placing” the polished silver slightly above Zone VII. (The exposure “Zones” mentioned here refer to the exposure system that was developed by the late Ansel Adams and championed by other photographers such as the late Minor White. Zone V is neutral gray with a reflectance value of 18%. This is the average exposure value that all light meters are calibrated to achieve. Reflective values above Zone V represent progressively lighter values, those below represent progressively darker values. Zone VII is characterized as being very light, but with some texture. Zone IV is characterized as being somewhat dark, but with definite detail revealed.) A reflective one-degree spot meter was aimed at the polished surface of the relicario and the flash was tripped. Had the exposure that was indicated by the meter (Zone V) been used, the silver would have looked not like polished silver, but more like medium dark gray. Instead the indicated aperture was opened by just over two f-stops to obtain an exposure (Zone VII+) in order to render the polished silver as polished silver. The flash power packs had been set at a low power so the calculated test exposure after Zone adjustment indicated an exposure of f 8.0 at a shutter speed of 1/250th of a second. Consequently, I increased the power setting on the flash power packs so that the Zone VII exposure was f 32.7.
I then had to calculate the bellows extension factor to adjust for the addition of the 16mm extension tube that enabled me to focus the lens closer to the miniature art relicario. Bellows extension factor refers to the fact that when focusing any lens very close, the marked apertures on the lens barrel no longer indicate the actual light transmission. The closer one focuses on any object the less accurate these aperture markings become. In reality the aperture markings are truly only accurate when a lens is focused on infinity. As a practical matter, this phenomenon is only significant when one focus at an object that is 8 times or less the focal length of the lens being used. Often one must change camera positions several times to determine the best perspective from which to photograph miniature three-dimensional art. Even small changes in the distance between the camera and one’s subject can result in significant bellows factor variations. One can calculate the proper bellows factor extension and thus apply it to the exposures for each of these variations using a formula. This becomes quite tedious.
There is a much quicker and easier method that is available to SLR film camera users whose camera view finders can be removed to allow direct access to the focusing screen. Calumet Photographic offers an inexpensive device they call simply “Exposure Calculator”. It is a small, two-part device. To calculate the bellows factor one places a 2x2” (5x5 cm) plastic card at the principle front plane of the art to be photographed. The card must be directed flat on to the camera lens. After removing the camera’s viewfinder to gain direct access to the focusing screen, one measures the projected image of the card on the screen and compares that measurement to the second part of Calumet’s exposure calculator. This second part is a short plastic “ruler” with logarithmically derived scales. One scale indicates the bellows factor in f-stops, the other scale indicates the proportion (percentage or magnification) of the image being made on the capture medium (film). Unfortunately, removable focusing screens are extremely rare on digital cameras, thus requiring use of the formula. On the “bright side” though, if one has a good meter and reads the unadjusted meter reading (without bellows compensation), one can estimate the bellows extension factor and make a test digital capture photograph and from there make any additional compensation adjustments to the lens aperture. Warning: there is the temptation to shoot a digital image that is not properly exposed and then to rely on Photoshop or some other software to correct the exposure. This can be done. However, as is the case with film, making a proper exposure in the first place always results in a better photograph.
Back to our example and applying the bellows extension factor to our indicated, unadjusted exposure of f 32.7 @ 1/250th of a second: The bellows factor as indicated by the Calumet device was 1.7 f stops. Therefore I opened the aperture on the 150 mm lens with its attached 16 mm extension tube to f 22. This aperture gave sufficient depth of field (focus) from the leading edge to the rear edge of the miniature relicario. Note: When using electronic flash as in this case one must make sure that the camera’s shutter speed will sync with the flash being used. There is a very brief delay when one trips the shutter before the flash fires. This is so that the shutter can open. With cameras who have leaf type shutters the shutters sync at all shutter speeds. With focal plane shutters the flash sync speed may be as slow as 1/60th to as fast as 1/250th of a second normally. Check your owner’s manual. Also. Whatever shutter speed one uses with flash exposures, the duration of the flash itself serves as the effective shutter speed. In this example above the flash duration was approximately 1/4000th of a second. This insured that no camera movement affected the final image.
The Aesthetic Choices and Decisions…
Up to this point we have reviewed purely technical aspects of miniature photography as general background information and more specifically in describing how the above photographs were made. Equally important is the thought that went into determining how best to capture this miniature art object photographically so as to “explain it”, that is, in order to reveal what it looks like and how it is made. It is a “delicate” piece with intricate painting and a complex finial surrounding a simple three-dimensional geometric shape. This is a very sterile description of this extraordinarily beautiful miniature art object. The photographic “description” of this particular miniature art is far more complete by viewing the two side-by-side photographs.
A quick examination of the object ruled out any single photograph as being able to adequately reveal the nature and design of this relicario. Two images were necessary to accomplish this. The frontal image alone does not convey the three dimensional shape or the beaten rear silver case. Therefore, both the frontal view and a ¾ side view were made. A black background was used in order to isolate the relicario so as to better reveal its shape and so as not to introduce what I refer to as “visual noise”, such as texture or even a gradation type background. In making the choice of a black background small reflective foam core panels were carefully place below and to the sides of the miniature art. These, in addition to the main light, a 3x4 foot (91x122cm) soft box, served to define the surface and edges of the art. A few black strips of paper were taped to the white foam core reflector panels on the ¾ view so that the delicately beaten facets of the rear silver case would be immediately, but “softly” apparent. The result of these aesthetic decisions are a pair of mutually supporting photographs of an extraordinarily beautiful and rare miniature art relicario whose inherent value as a piece of art does not require any ancillary photographic backgrounds. As an art object, “The Coronation of Our Lady of Copacabana” stands on its on merit. My goal as its photographer was to let the viewer see this.
This article was originally published in 1994.