Experiments in Coin Photography - 2008

It has been several years since I have updated my material on the photography of ancient coins so this page will offer opinions developed since my earlier pages which are linked at the bottom of this page. Opinions may differ on whether my coin photos have improved in these last few years but at least a few images have benefited from what I have learned. There is room for several opinions on the questions that face a photographer of ancient coins and we all must decide which style best renders the coin as we would like it to be seen. It should be obvious that some coins, like some people, take better pictures than others. We have to decide if we are trying to make each subject "Hollywood Handsome" or going for "Passport Photos" which show the coin with brutal honesty. I'm not talking about retouching out flaws but just lighting to enhance good detail and to minimize surface irregularities. A photographer can make a $500 coin look like a junk box special. It takes more care to make a junk box special look like a $500 coin.

Cameras and Lenses

One thing that will not be found here are specific recommendations for cameras suitable for coin photography. Today, there are so many models of digital cameras available that no one person could know them all and still have time left over to do other things like take photos of coins. We will, however, talk about a few characteristics to seek out when selecting equipment. I use a Digital Single Lens Reflex (DSLR). Mine happens to be a Canon 30D but equally good results would be possible with any number of other models made by half a dozen major manufacturers. Before buying my first DSLR, I took coin photos with the digital camera class usually called 'Point and Shoots'. Most digital point and shoot cameras have some degree of close up or 'macro' capability. The feature to watch is whether the macro focus feature works at the longer focal lengths offered by the lens or only at the shorter end of the zoom. While a camera may be capable of focusing to, for example, one inch, this feature is of little use if it only gives a field of view several inches across. We need a lens that may only focus to half a foot but, at that distance, fills the frame with a small coin. Avoid cameras with macro function restricted to the wide angle setting or plan on buying an accessory close up lens that will add this feature to the telephoto zoom offered by your camera. Most cameras will have a tripod threaded mount on the bottom. You will need this to mount your camera securely for sharp photos. Avoid cameras that you must use hand held.

The great advantage of DSLR's is that the lenses are interchangeable so you can mount an appropriate one for coin use or add extension tubes that will convert the standard lens to something that can focus on a coin. I use a 100mm Canon macro lens which allows filling the frame with small coins while still six inches from the front of the lens. This distance could be increased by using a 150mm lens or reduced with a 50mm even though each lens could fill the frame with the same coin. A reasonably good working distance allows greater flexibility in arranging lights in a way that the camera does not cast a shadow on the coin. From a bit under 6 inches, my rig fills the frame with a coin just under 15mm in diameter so most of my images are taken a bit farther back since most coins are over that size. A collector of medieval thalers might consider a shorter lens to shoot the larger coins while a specialist in Greek fractional silver might appreciate the additional distance allowed by a longer lens.

Camera Support

Of all equipment important to shooting coins, I will be least helpful when it comes to a way to support the camera. As shown in most of my images, I use the frame of an old Durst M600 enlarger which I have owned since the late 1960's. I removed the enlarger head and mounted a tripod ball head to the adjustable track. It works like a charm. Those who do not happen to have a lifetime of photo junk in the attic may consider using a commercial copy stand or a tripod that allows shooting straight down.The illustration here is just one way a tripod can be pressed into service but each model will present its own opportunities and challenges. Many tripods allow inverting the geared center column so fine adjustments are possible. Using a model lacking this feature often requires making coarse adjustments in height at least partially with the coin support. This can be as simple as raising the coin level with a stack of boxes or placing the tripod on the floor next to a corner of a table. Tripods that lack the capability to shoot straight down often can be tilted by lengthing one leg more than the others. Just be careful not to create something that will easily fall over and damage the camera. My example in this photo is on the verge of violating this 'rule'. I'll leave details to you but you must find a way to secure the camera so pictures can be taken with no blur causing camera movement.

Lighting

As I progressed through various styles of lighting coin photographs, I have shown a preference for methods that allow easy reading of coin legends and avoided glare that blanked out areas of the coin surface. Earlier this took the form of 'pseudo-axial' lighting which appeared to come directly down on the coin from the camera itself. I still like this form (discussed on earlier pages) but have found it easier to employ a circular 'ringlight' which results in a more or less even shadow on all sided of the base of each letter of the legend or other raised device on the coin surface. While I own a so-called ring flash, I have found it relatively worthless for coin photography. Minor changes in coin position can make major differences in the placement of shadows and it is much easier to preview these changes when using a continuous light source. Some time ago I abandoned high intensity (hot!) halogen lights in favor of compact fluorescent bulbs that provide a larger, softer light and produce much less heat. As long as the camera is kept far enough back from the coin that the bulb can shine down at a small angle off the axis of the lens. The angle that works best varies from coin to coin and minor changes in light position (near, far, right, left, tilt) can improve one coin and do nothing for another. The fluorescent ring light offers this same light quality but coming from all sides evenly making minor changes less significant. Some coins benefit from this type lighting more than others. This page will demonstrate this fact as we proceed. In general, the ringlight emphasizes raised legend detail and puts a shadow at the base of raised devices. It also tends to blank out the flat fields and makes the coin unnaturally bold. My ringlight was purchased at Staples Office Supplies store for $25 but I suspect there are other brands available that would do as well. A relatively broad but still directional light like that provided by coiled compact fluorescent tubes gives a bit more natural surface illumination but not quite as bold legends when compared to the ringlight. Opinions will differ as to which is better for any given purpose.

The ringlight is clipped to the stand so it also remains in the same place as the lens is raised and lowered. The gooseneck feature makes adjustments simple. The dowel stand is shown sitting in an old plastic refrigerator drawer which reflects a small amount of light back on the edges of the coin. This is particularly effective on thicker coins or when you want to separate the background cleanly and drop the coin image on another background (e.g. a map). Some coins hardly show any effect of the tray but it also can be handy retrieving coins that fall off the dowel. The hole in the side of the drawer allowed insertion of a background light but I rarely feel the need for this since I prefer darker backgrounds.

For comparison the above image shows my standard compact fluorescent rig. As on all my recent rigs, the camera is supported by an old enlarger frame (Durst M600) which I have owned for decades. The bulbs are held in the same old double socket movie light bar which I started using when I had my Minolta point and shoot. Back then, the two bulbs flanked the lens of the camera and provided almost axial light due to the relatively small diameter of the lens. Now the spacing is a bit tight to place the bulbs around the lens but this does give a broad light source even if no diffuser is used. The light is mounted in a way that it can be slid around and tilted as needed to give pleasing results when viewed through the finder. One easy way to light coins is to set up next to a window providing bright but not direct sunlight. This can be on a cloudy day or on a north exposure. My rig is shown here sitting on a stool with a lazy susan so the whole rig can be rotated to provide optimum light direction for each coin. While easy, this method suffers from inconsistency due to changes in weather and time of year. Results may be more natural looking but not particularly pleasing. Rather few coins I have tried come out better this way than one of the other choices but it often does provide an accurate view of patinas and coins that need directional light. That usually mean coins with smooth surfaces and low relief. I do not own many coins like that.

Coin Support

I am very fond of setting a coin on top of a dowel rod tall enough that the background is out of focus. This is easiest with a black background but can be used with other colors as long as care is taken to light the background in a way to erase shadows. Background shadows are no problem with the ringlight or with a black background. When using a black background and directional light, the dowel can be surrounded by a black interior tin can (shown in my illustration of the window light rig) making the black background even blacker. Again, this works less well with the ringlight which tend to light the inside of the can. As shown in this illustration, it is possible to mount the dowel (balanced carefully or using hot melt glue) on a piece of glass which is set above the background enough to force the shadow out of the field of view. This solves the problem of a shadow from the dowel when using other than a black background. The ringlight will glare on such a piece of glass but this system can work well with directional light as long as care is taken to have the glare fall somewhere other than the part of the glass in the field of view.

The glass support technique is best for a white background but it is possible to get carried away and use a photo or map under the coin. This is a trick left over from film days. With digital, it is easier to create such images in postprocessing.

Minor Accessories

Shutter Release: When shooting small objects (even large coins are 'small' for this purpose) it is very important to avoid jarring the camera when releasing the shutter. One way to help here is to use a cable or electronic remote release (as is available for your camera model). This simply makes it easier to trip the shutter with care. These releases can be wired or send an infrared or radio signal to the camera. A wired version is shown in my pictures of the CFL and window light set ups. If your camera lacks provision for such a release, a similar effect can be achieved using the self timer which delays the shutter about 10 seconds after you press the release. This gives a little time for the vibrations you introduced with your finger to settle down. Another feature of some DSLR camera models that comes in handy is the 'mirror lock-up'. Setting this will trip the reflex mirror a few seconds before releasing the shutter. This is particularly good at damping vibration caused by the raising of the mirror itself. The desirability of this feature depends a lot on the sturdiness of your camera mount and how violently the mirror is raised. This is not a needed feature with point and shoot cameras (which do not have moving mirrors).

Reflectors: Some coins (often with high relief) will have a shadow somewhere that can use a little extra light. Pieces of aluminum foil are easy and cheap. These can be under the coin for edge light (as in my CFL photo) or above and opposite the lights as fill. This is a place where the photographer can preview results through the camera and adjust accordingly. Even if you are using my refrigerator tray 'edge illuminator', a small piece of aluminum foil can throw a little extra light where you desire. While it has nothing to do with lighting, the refrigerator tray or other box can be handy catching coins that get knocked off their perch. The value of this will be more obvious after you have searched the floor a few times.

Lens hoods: While not shown in many of my set-up images, it is usually good to protect the lens from glare with a lens hood. The length of the hood will usually be shorter than the longest possible since it can get in the way of lighting arrangement. The cheap rubber hoods as shown in my glass background image are perfectly acceptable. Some macro lenses are built with the front element recessed making a hood less necessary. Whether you are using a hood or not, it is best to arrange lights so they shine on the coin and not on the front of the lens.

Extension tubes: Very small coins require a smaller dowel and the addition of a 68mm set of Kenko extension tubes filling the frame with a 5mm diameter coin. There is actually a coin on the small dowel seen here but the image is too low resolution to show it. Dowels over 1/2" are rarely needed to support even large coins and those under 1/4" are hard to use unless you add a small speck of clay to the top as an adhesive. While I prefer to shoot coins raised off the background, the smallest are often shot laying on a surface which can be cleared in processing. At the minimum 4" working distance (as shown here) the ringlight is starting to suffer from the hole in the middle of the light circle being too large for good lighting. Fortunately, I have very few 5mm coins! While my images usually have black felt backgrounds, other colors can be used if care is taken to light it evenly. Very small Greek coins tend to have rather high relief and often have rough surfaces in proportion to their diameter. This suggest they are best lighted with the ringlight or (as with these two examples) a broad bank of CFL lights at a rather high angle.

At this point we will examine some examples. In each set of three images, the top row was taken with the ringlight, the middle row with the CFL lamps and the bottom row with natural light from the window. Below each set is a discussion of what this photographer sees as the strengths and weaknesses of each technique. Others may or may not agree. The point here is not to tell you what to like but how to control the variables that might lead you to images you might find pleasing. Obviously there are many other ways coins could be lighted including some that might even be better than anything shown here.
The Alexandria mint denarius of Commodus is fully cleaned and light silver/gray. Each of the three images has something to recommend it but my favorites are the ringlight reverse and CFL portrait. The coin has two dark spots on the portrait that are overstated by the window image but are played down on the other two. My favorite? I can't decide. The Rome mint AE3 of Constantine I has a rough green patina. The mintmark is a very rare (Greek script 'Eros') variety so it is extremely important that it be rendered clearly. My choice for this coin is the ringlight (top) since it really smoothes the rough surfaces but selling the coin fairly would require using the CFL image. The antoninianus of Probus has traces of toned silvering but is mostly a toned bronze. While the ringlight shows the reverse most clearly, the CFL portrait is more pleasing and makes it my overall choice for this coin. As with the Commodus, no image is really bad. All this proves is that nice coins are easier to shoot.

Moving on to poor condition coins, this denarius of Julia Domna is rough and worn. Oddly the end of the obverse legend is least clear with the ringlight making it my last choice. The low relief favors the window light image making this a rare exception to my usual rule. This coin needs to be reshot. At 10mm diameter and .3g, this Syracuse hemilitron presents a different set of challenges. Since there is no legend, the portrait is the first consideration. I favor the CFL rendition. The CFL also plays down (but still shows) some of the surface problems overstated on the ringlight image. Much later but also from Syracuse, this 27mm bronze has a shiny green patina with several rough patches. The high relief portrait makes lighting difficult but handled best by the ringlight. The top of the reverse is poorly struck making the excessive relief from the ringlight welcome even though the CFL is more accurate.

....and back to prettier models. These three coins are included just to make the point that changes in lighting make different images but it is not always obvious that one is better than the rest. If I were to have to select only one of my lighting set-ups it would have to be the CFL (best average) but it is nice to be able to fall back on one of the others when needed. Look closely at various details and decide which photo you prefer. I like them all and all could use some work. Is it worth giving up one good point to correct another fault? What can be done to improve the lot?

Postprocessing - Yet Another Tool

An area of coin photography I have just begun to investigate is postprocessing. All of my images are processed to some degree but the above example demonstrates a beginning effort that could well prove more trouble than it is worth. Five images have red arrows showing the direction of light used for that image. The photo in the middle of the bottom row is a stack of five layers consisting of the other images blended together using Photoshop Elements (and equally possible with several other software packages). The result combines detail of the various directional images and produces a result that looks a bit like each of its parents. With practice, a skilled worker could manipulate this blending of layers to improve the overall balance and make the whole a more pleasing photograph. I am no skilled worker. This was my first attempt at a coin stack. I encourage anyone interested to give it a try and see if there are benefits to be gained for better coin imagery in this manner.

Please visit my pBase Gallery:

My pBase Coin Gallery with many new photos and some discussion

Other photo postings:

The following pages were posted to my coin site in years past. Some of them have become a bit dated but there is some value left here and there. All are invited to visit them and any other pages on my coin site.

Coin Photography with a Microscope
Photographing a Nero Dupondius
Coin Photography with the Canon 300D
Coin Photography with the Minolta D7i
Coin Photography with the Minolta D7i (earlier page)
Coin Photography with the Nikon 990
Coin Photography (pre-digital page)

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