Photographing Ancient Coins

2003 Update

It has been a bit over 35 years since I first photographed an ancient coin. Across that span I have used a number of different cameras and made slow progress toward being a better photographer. I never will accept the current level as the best I can do and never will think my current methods are best for all people at all times. Since my web pages first addressed the subject of coin photography, my opinions and practices have changed quite a bit. The rapid advance of digital camera technology is responsible for much of this change. My current digital camera is over a year old and nowhere close to state of the art. When time comes for it to be replaced, I will probably feel the need to write a page like this on the new camera. Those interested in the subject may wish to visit my last photo page covering much of this same material in a similar fashion. This page is really just an update to that page which I do not wish to change since that version is what appears on the CD version of my site. My previous pages on coin photography attempted to address the subject in a manner that might be useful to owners of other equipment but the vast range of cameras now on the market leaves me at a loss to make this page cover all the bases. Therefore, I will explain what I am now doing in terms specific to my equipment and leave it to anyone interested to adapt the techniques to their situation. Therefore, this page can be named:

Coin Photography with the Minolta D7i - My Way

My current coin photography rig is a Minolta D7i camera mounted on an old (1960's) Durst 609 enlarger stand from which the enlarger has been removed. The camera is attached to the stand using an equally old Leitz ball and socket tripod head. Light is provided by two compact fluorescent bulbs (new at any Home/Hardware store) mounted in (another refugee of the 60's) two socket movie light bar which has been attached to the enlarger stand so it stays in the same relation (very close) to the lens as the camera is raised or lowered. The coin rests on a wood dowel passing through a scrap of black felt and set into a wood block base. Small coins (under 30mm or so) require an auxilliary close up lens to fill the frame with this camera. Let me repeat that I am not proposing that this is the only or the best way to take coin photos. It is, however, the way the examples on this page were made. If you like them, feel free to copy these techniques. If you are doing better, feel free to tell me how I could improve my results by emailling me at dougsmit (at) comcast.net replacing the (at) with @. Not providing a clickable link here is a feeble attempt to keep automated spam systems from farming this email. Persons reading this page are invited to send questions or comments. If images are sent they MUST be .jpg format. My system is set to delete any attached file so sending .doc or other formats is a waste of your time.

Each component of the system will be discussed below. Sample images are all reduced greatly to fit this page. I will be happy to email a sample image to anyone desiring to se the full size file and willing to receive a file that large (dial up users be warned).

Camera

The Minolta Dimage 7i was one of the leading "prosumer" digital camera models last year but has been replaced in the Minolta line first by the D7Hi and recently by the A1. As far as I can tell, the upgrade features of these two models would not prevent them from being used equally well for the techniques described on this page. This camera produces a 5 Megapixel image file with dimentions of 2560 x 1920 pixels. The samples shown on this page are combinations of two images allowing both sides of the coin to be shown in one image. While I use (and recommend) Paint Shop Pro by JASC, you will get equally good results with Photoshop or a host of other programs capable of cut and paste operations. I consider it very desirable to combine images in this manner rather than to make your viewers open two separate files to see your coin. All images on this page have been reduced in size to fit the screen but I will be happy to email any of the full size images on request. I do ask that dial up users think seriously what they are requesting since downloading that size a file will take a while even at the best dial up speeds.

A scratched fourree of Larissa demonstrates the modelling effect of soft light on a high relief coin. Three dimentional detail is emphasised while the scratches are recorded accurately without being exagerated. Somewhat polished, this Ptolomy I tetradrachm illustrates the problem of retaining detail over a wide tonal range. This reduced version can barely show the delta die cutter initial behind the ear which is clear in the full size image.

I shoot images with the camera set to what Minolta terms 'Normal' compression. This is not the finest setting on the camera but my personal experience is that the quality I get is satisfactory for my uses and file sizes are smaller than would be produced by finer settings. Images posted here are further compressed so what you see here is not as good as you could get at home if you chose to work in other settings. I, personally, can't see enough difference to make my hard drive fill up twice as fast but this is a decision each of us must make. If you feel you must have the best possible images, you might want to save files as RAW but don't even think of mailing me one of them. The camera is capable of shooting smaller images than the 2560 x 1920 pixel size that I use for most work. If you are recording a huge number of coins and space on your memory cards is lacking, you may prefer to shoot at one of the smaller image sizes offered by the camera. Remember, though, you can always resize an image down and lose nothing but expanding a small image to a larger size spreads out the quality and looks terrible.

The feature that made me select the Minolta D7i was its lens. More exactly, the fact that the lens was configured to enter macro (close-up) mode at the long end of the zoom. Macro focus at the long end of the zoom allows a coin to be photographed from several inches away. This becomes more important when attempting to set the lights very close to the lens as required by my lighting technique described below. This camera is capable, without accessories, of filling the frame with a sestertius size coin. Denarii will require an accessory or croppping the image. Certainly there are cameras on the market that will fill the frame with a denarius. Some other cameras only allow close focus when the lens is set to a wide angle setting. They may allow focus on very small objects but this is achieved at a distance less than an inch from the lens. Being so close makes it nearly impossible to light the coin in a pleasing manner. My experiments with accessory or auxilliary lenses will be described in a section below.

The lighting described on this page produced the best result I have yet had when shooting a cup shaped coin like this Alexius III. While the image has some glare in the highlights, it seems to accent the curve of the coin more than obscure the detail. This Antonia dupondius with reddish brown patina in recesses and bare orichalcum highlights is a rather accurate rendition of the coin. Minor pits appear in the image without being over stressed as might be the case with harsher light.

The other big attraction of the Minolta 7i was the electronic finder that displayed the image just like it would be recorded in terms of exposure. While the camera has a meter and does relatively well with automatic exposures, setting the camera for manual exposure and adjusting the shutter speed until the exposure looks just right has become my method of choice. Cameras with optical viewing systems (including the high end digital SLR's) will require checking the result after exposure or learning to use the histogram features all good cameras (including the Minolta) offer.

My experience with the autofocus of this camera for macro subjects has been very good as long as the camera is firmly supported on the stand. The default system selects from several points on the image and sets focus correctly as long as the coin is perpendicular to the lens axis. For shooting coins on a slant, it is best to shift into the mode allowing the user to move the spot of focus. While the camera allow manual correction of the focus by turning the ring at the back of the lens, I have rarely found this necessary for coins.

A Provincial AE28 of Septimius Severus from Hadianopolis servses to illustrate the effect with a polished green patina. The challenge is to maintain the correct green color as well as detail on the brightly polished surfaces. This as of Vespasian shows considerable detail but has a lightly rough and very dark patina. The image here is mostly of the glare from the nearly black surface but looks like the coin when viewed in strong light.

Camera Support

As I have maintained before, good coin photos MUST be made using a tripod or other solid support for the camera. For shooting down on a coin, I have had great success with copystands of various types. Since commercial stands often have built in lights which are not particularly well placed for coin photography, I recommend making a stand (for much less money) with no attached lights. For this purpose I have adapted the base and upright column of a photographic enlarger I used while in college in the 60's. Similar items may be available in larger cities at stores selling used photographic equipment. This model uses a hand crank to raise and lower the head of the enlarger (now replaced with the camera) along the upright column. The camera is attached to, and held away from, the column by a ball and socket tripod head, also surplus from the 60's, which will allow minor adjustments of angle while holding the camera securely in place. Each combination of camera and stand will require a different means of attachment. I realize that it would be difficult or impossible to find the exact models of old equipment I have used here. Anyone wanting to 'copy' this system will need to copy the general idea rather than the specifics. While a bit less versatile than the height adjustable enlarger stand I now use, the camera stand made of wood scraps shown (center photo) on my last photo page will allow equally good results as long as the positions of the holes to secure the ball and socket head are placed at the appropriate places on the upright considering the size of the coins to be photographed. The important point here is that the camera MUST be securely attached to some support that will hold it solidly in place with relation to the coin being photographed. If portability is desired, the entire rig can be reduced in size and fastened to the camera as an accessory on the front of the lens. All that is important is that every photograph be taken with the subject coin and the camera held in exact alignment for the split second the exposure is made. Movement of even a fraction of a millimeter will ruin the photo.

This sestertius of Caligula has many minor flaws which show to a degree similar to the coin in hand. This Provincial tetradrachm of Trajan Decius from Antioch has a finely grainy surface that photographs well in the light discussed on this page.

Accessory Lenses

8 1/4" Xerox lens used as auxilliary is well corrected for color. Single element close-up lens has severe chromatic abheration.

Since the Minolta D7i can only focus closely enough to fill the frame with a sestertius size coin, it was necessary to find a way to get closer when shooting smaller subjects. If the camera offered interchangeable lenses, the answer would be to insert extension tubes between the camera and the lens. Unfortunately, the Minolta has a fixed mount lens making this impossible. The second best method is to attach to the front of the lens a positive diopter auxilliary lens. These are sold under the name "close-up lenses" and are avainable in several strengths using a scale of +1 to +10 (weakest to strongest). The lenses can be stacked adding their values (a +4 and a +6 used togther give the same results as a +10). Use of stacked lenses can degrade the overall quality of the image so I recommend avoiding the practice unless you are unable to obtain the needed power lens to fit your camera. Many close up lens sets sold contain +1, +2 and +3 lenses which I have found to be too weak to use with this camera for small coins. A +6 lens seems to give good results with denarii but may be too strong for larger antoniniani for which a +4 is a better fit. Standard single element diopter lenses introduce a bit of chromatic abheration which shows as aring of color fringing around the edges of the coin. This can be improved by using (more expensive) color corrected, multi-element close up lenses. Being the cheapskate I am, I adapted an old (you guessed it, 1960's surplus) 8 1/4" lens for use as a closeup lens (about +4.75 diopter). The results are excellent with no visable fringing. For very small coins, an old Pentax 50mm lens is mounted on the camera as a +20 diopter extreme close up lens. All this playing around with accessory lenses was enjoyable to me but I will admit that, for most uses, quite decent results can be had simply by shooting as close as the camera can normally focus and cropping to the subject when the coin is smaller than a sestertius. Doing this is like using the center 3 Megapixels of the 5 Megapixel field so the results should equal those of many digital cameras used full frame.

This Larissa obol was photographed using the 50mm Pentax lens as an auxilliary (+20 diopter). At 8x10mm the coin is nearly the largest subject that will fit in the field. The light is now so close that much of it comes from the side giving a different result from those taken of larger coins from a greater distance. I do not find this as pleasing and will need to work on my techniques for tiny coins. This light certainly enhances the reticulated surface of the coin. Among my favorite and most challenging subjects is this Persian siglos with numerous countermarks. It was photographed with the 8 1/4" lens used as auxilliary as shown in the photo of the camera. Special attention must be paid to lighting coins of thick fabric to preserve the actual appearance of the chunks coin. To this end I added light reflected from a white card held at the bottom of the coin. This opened the shadow on that side and made the image appear more three dimentional.

Lights

The big difference between the technique described on this page and those from my earlier photo pages is the use of different lights. My previous light was provided by a small tungsten halogen desk lamp which was both high intensity and hot in operation. This lamp was so hot and so small that it approximated a point source light when kept at a safe distance to prevent melting camera, subject or the photographer. This has been replaced with a pair of screw based compact fluorescent bulbs sold to replace incadescent bulbs in table lamps. These bulbs put out much less light than the halogens and almost no heat so it is safe to move them very close to the camera position. I still try to avoid touching the bulbs to the plastic parts of the camera. The other major difference is that these bulbs spread their light over the 4 inch length of their tubes. Two, mounted in an old light fixture intended for use with an 8mm movie camera, makes a 4" x 5" directionless light source that simulates the light of a cloudy sky or expensive photographic 'softbox' system. To direct light that would otherwize be wasted back onto the subject, I placed a piece of aluminum foil around the back side of the bulbs. Unfortunately, these bulbs do not match any of the preset color temperature settings of my camera so it is necessary to use the manual white balance feature by metering off a white sheet of paper and saving the result in one of the camera's memory channels. Soft lighting produces a result rather like the axial lighting I prefered in my first photo page. Relief details are highlighted without overemphasising surface irregularities. The directionless light can be particularly good with high relief coins but can still be a bit harsh with overcleaned silver. In this case, it is especially important not to overexpose the image. Until recently I was using the camera meter to set exposure using the Aperture priority mode and setting the lens on the smallest aperture (f/9.5). Most exposures were acceptable but some coins were fooling the meter due to specular highlights or black patinas. The Minolta electronic viewfinder (EVF) displays what whill be on the image with good accuracy so I switched to manual mode and dial in the appropriate shutter speed to achieve the look I find most appropriate. My percentage of correct exposures on the first try has improved with this technique. I might warn that the images on the EVF seem to appear more contrasty than the saved file and I am usually happier with the result that I thought I would be when taking the photo. When in doubt, I usually select underexposure since digital files are like transparancy (slide) film in that slightly dark images look better than slightly light. Within reason, exposure can be fine tuned in post-processing (I use and recommend Paint Shop Pro) but no program can restore details in blank white areas.

A fourree stater of Poseidonia was shot with the 8 1/4" auxilliary described below and shown in the photograph of my camera rig. Also with the 8 1/4 auxilliary, this denarius if Septimius Severus has some mint luster, die polish marks and flow lines from striking past the edge of the reverse die. All show well in the photo.

Coin Support

Through all of my photo pages I have shown a preference for plain black backgrounds on my coin images. While my previous page did offer the option of a shadow free white background using a glass support, I really prefer my reliable upright dowel coin stand. The coin rests on top of a dowel which has been set into a scrap of wood so that it is straight and small enough diameter that it will not be seen from the camera position. For most coins, I have been happy with a 1/2" dowel about 6" long. For smaller coins I have a 1/4" version. If I were shooting a large number of larger coins, especially if they were soft modern gold that might be damaged if they fell off, a 1" dowel would be useful. Many ancient coins have high relief details that make them sit unevenly on top of the dowel. Once I used a bit of clay (Plasticine or other non-sulfur clay!!!) to allow the coin to rest flatly. I discovered that the same end could be reached by drilling a concave depression in the top of the dowel so the head of the coin would fit into this cup and allow the reverse to be flat. When shooting the portrait side, the reverse fits well on the outer ridge of the dowel. I still need clay on occasion but this 'trick' has kept me from having to be careful to remove clay residue from every coin I shoot. This, again, would be critical for shooting delicate proof surface coins or soft gold more than it is for my collection of junk box finds. The background is provided by a piece of black felt with a hole just large enough to pass the dowel.

Commodus Sestertius showing result of white background fabric with soft lights. There is some coin shadow remaining at 5 o'clock but little hint there was a dowel under the coin. The polished gold of this solidus of Theodosius II shows typical surfaces for worn gold removed from jewelry. It was shot using the 8 1/4" auxilliary.

My new lighting system discussed above allows a nearly shadow free result on the background. My earlier lights cast a strong shadow on the felt and required care to minimize the exposure on the felt to keep the background an even black. The new lights are so close to the coin that the background is usually not a problem. Replacing my normal black felt with a white piece illustrates this situation. Some may like the effect and want to retain this gray background but it is easily removed (made blank white) in post-processing. A longer dowel should produce a more even background. I do not recommend the use of a short dowel under any circumstances since it is important that the background be very out of focus to avoid distracting textures.

This page can not be a comprehensive treatise on coin photography. I have glossed over some points that were covered on previous pages while repeating others that struck me as worth reinforcing. If you have not seen my earlier coin photo pages, I invite you to visit each on the list below. Where there is a conflict with an opinion expressed here, be warned that I have changed my opinion on several matters since my first 1997 pages. This page is where I am in October 2003. I offer no guarantee about November.

Older Photo Pages:

Coin Photography with the Minolta D7i (earlier page)

Coin Photography with the Nikon 990

Coin Photos with a Microscope

Coin Photos with a Microscope samples

Photographing a coin of Nero

Coin Photography (pre-digital page)

Coin Imaging with a flatbed scanner

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