How about helping me decide what I should write about next?

I just finished writing a couple of ebay guides this week about coin photography and I'd like to start another guide next week. Of course, it's going to be something about photography, but I'm open to suggestions.

Here are a few topics I've thought of...

• Using Light Tents (you know, like those fabric cube things, for getting softer light)
• Choosing and Using a Tripod
• Different Ways to Take Close-up Photos

Those are just off the top of my head. You can either comment on those or suggest some others.

If you'd like to see my other guides, including the new ones on coins, here's the link

CameraJim's eBay Photography Guides


Thanks!

Need to take photos of coins? I've completed and posted a new eBay coin photography guide, based on material I've been putting together on my blog. The guide will help you show of your coins in order to make more cash.

Heres the link....

Coin Photography and Lighting

If you find the guide useful, I would appreciate it if you would click the "Yes" button at the bottom of each guide page.

I have also posted an off-ebay version which uses larger photos and is all in one part. You can find that one by accessing camerajim.com and clicking the coin photo on the first page.

Axial Lighting

Axial lighting is a little-known technique which I think has great application in coin photography. In this technique, the light path travels straight back and forth along the same axis as the direction of the camera lens. Primarily used with microscopes or forensic photography, axial lighting can produce shadowless, yet high-contrast images with startling levels of detail.

An Axial Lighting Setup

As shown below, an axial lighting setup requires a flat and clear sheet of glass which is placed at a 45 degree angle to both the light source and the camera lens. Most of the light hitting the glass passes through it, but a significant portion of light is reflected downward at the subject - in this case, a coin.



You will notice that I've used a small black object to shield the coin from any direct light. I've also darkened the room to avoid any stray reflections in the glass. Therefore, the camera lens sees only the light reflected from the surface of the coin.

Here is one coin photo I took using axial lighting, with a black cloth used as the background...



What happens is that any smooth surfaces that are perpendicular to the light path, such as Liberty's cheek or the raised faces of the lettering of the coin, reflects a lot of light back to the lens and thus show up brightly. Any surfaces that are not perpendicular, such as the Liberty's profile or the edges of the lettering, reflect light away from the lens and show up darker. Smooth surfaces, such as the worn areas in Liberty's hair, show up very brightly. Slightly textured areas, such as the background field of the coin, show up darker.

In other words, there are no real shadows here, just brighter and darker areas, dependent on the angle, texture and reflective characteristics of each part of the coin. Note that I controlled the exposure in this photo so that the brightest areas would not wash out entirely. This makes the coin look somewhat darker than you would think from seeing it in person, but the emphasis here is on detail, not shine or luster.

This high degree of detail can be seen even more clearly in this larger version of the above photo...

Larger Axial Lighting Photo

Modified Axial Lighting

You can also control and modify the appearance of a coin with small changes in the angle of the reflective glass, causing the light path to be slightly off-axix, as in this example, where the glass was tilted just a couple of degrees more...



As you can see, even a small shift of the light off the primary lens axis loses some of the available detail, but it also restores the lustrous appearance of the coin.

Shooting a Darker Coin with Axial Lighting

Another advantage of axial lighting is that it can increase the contrast in a dark coin, such as an old copper cent. Such coins, shot with traditional lighting setups can sometimes look like featureless blobs, making it hard to see any significant detail. However, axial lighting and a well-chosen exposure can reveal much more...



In person, this coin is quite dark. To do it justice in an eBay auction, you might want to include both an axial lighting photo and another taken with conventional lighting.

Axial Lighting for Proof Coins

If you'll pardon the pun, the place where axial lighting really shines is with proof coins. The mirror finish of the fields on such coins makes them notoriously difficult to shoot. Any light striking such a mirrored surface at an angle will simply reflect away from the camera, leaving behind what look like featureless black pools surrounding the satin-finish design elements. Here is an inexpensive proof coin, shot with simple side lighting...



And here is the same coin, shot using axial lighting...




Choosing the Right Lighting for Your Coins

As I said when I started this coin photography series, there is no single approach which is best for all coins. In fact, more than one type of lighting can be used effectively  to show different aspects of a single coin. So, I would recommend experimenting with all of these techniques and even to invent variations of your own. The idea is to communicate with people about your coins. For that, a wide lighting vocabulary can be your best tool.
 

Light Tents

There are all sorts of light tents promoted on eBay for product photography, including expandable fabric cubes, enclosed boxes and even a "coin dome" specifically for coin sellers. Call them what you will, each is nothing more than a way to completely surround an object with a translucent light diffusing material, providing soft light from all sides of an item. Some commercial light tents cost $100 or more. Thankfully, you can make a very good light tent for coin photos for the price of a gallon of milk. And, you get to drink the milk!

The Milk Jug Light Tent

Creating a light tent from a milk jug requires nothing more than a clean, empty milk jug and a sharp knife or scissors. You simply cut off the bottom of the jug to the desired height, place it over your subject, light it evenly and shoot through the neck of the jug. If the neck is too small for your camera lens, you cut that off to make the hole large enough. Here is one of these modified milk jugs in use on my copy stand...



I cut this jug down only slightly, but you could easily make a few milk jug light tents of different heights to match the focusing distances needed for various sizes of coins. For even more light diffusion, you could use a white orange juice jug.

In the photo above, I've shown the milk jug illuminated by only one light, but it is more common to use two lights, with one on either side. This surrounding lighing creates the most even effect. The photo below was shot through the milk jug with one strong light on the left side and a weaker light on the right side..



As you can see, this produces a very soft light which brings out the surface of the coin well. However, a light tent also results in a lower contrast image, with less definition between the brightest and darkest areas. This in turn leads to a loss of fine detail in raised design elements. Small nicks and scratches are also less prominent.

Smoother Light - Lower Contrast

Portrait photographers often use a second light as a "fill" light. Its purpose is to lighten shadows and smooth out image tones. Often, this second light can be provided easily and at almost no cost by a reflector which directs some of the main light back at the subject.

At the close distances required for coin photography, using reflector as your fill light is a cinch and can be very effective. I've added just such a reflector to the setup below in the form of a small sheet of foamcore board which is white on one side and black on the other. Foamcore board is often used in mounting photos and other artwork. A sheet of white posterboard or any other broad and flat white material will work, too.



Notice that I still have my plastic diffusion sheet on the left and I have placed the reflector board so it not only leans against the camera but also extends over it a bit. This helps to reflect some light directly back at the surface of the coin.

In the photo below, this lighting setup has helped to bring out the luster in the coin while still preserving excellent detail. It may not be the absolutely best coin photo, but as I said earlier, I don't think there is such a thing. However, I think it is a very good lighting arrangement for most coins.
 

Contrasty or Soft Lighting

After lighting direction, the size of a light has the most to do with how an object will look. By "size" I don't mean the power of the light, but rather the physical area of the light source, in relation to the object.

A tiny, point source of light will create bright highlights and deep, dark shadows. This increases the sense of sharpness in a photo, but it can also obscure important factors such as toning or luster on a coin.

A broad light source will reduce the harshness of highliights and soften shadows. While some sense of sharpness is lost, the increased visibility of other details can make this a good tradeoff. Carried to an extreme, however, a very broad light source can make a coin look flat and lifeless.

The distance of the light source mattters, too. Although the sun is a very large object, at its distance from earth it occupies less than 1/2 of a degree in the sky, so it acts like a point source, producing very contrasty light. On the other hand, a small household light bulb placed a couple of inches from a coin can act like a very broad light source.

Choosing between contrasty and soft lighting for coin photography is a subjective matter, but it is easy to get the degree of contrast you want by changing the size of your light source.

Creating Softer Light wth a Diffuser

The easiest way to make a light source larger and softer is with a light diffuser. This can be any form of translucent material placed between the light and the subject. The diffuser then becomes the light source, which is now as broad as the lighted area of the diffuser.

Professional photographers use many fancy types of light diffusers such as scrims and soft boxes, but at the scale of coin photography you don't need anything that elaborate. For instance, you could use something as simple as a sheet of plastic from an overhead fluorescent light, as in the setup below.



I propped this plastic sheet against my camera, but you could also mount one directly in front of a light with a simple clamp (being careful of overheating, of course).

This sheet of plastic has now turned my small light source into one that is a full foot square. The result is a photo such as below...



To my eye, this is an improvement over the bare-bulb photo I showed in my last post, but it still isn't good enough. The single light source still gives uneven lighting across the face of the coin and the angle of the light leaves the shadowed areas a bit dark. In my next post I will add a second light in the form of a reflector to correct these problems.

I'll be discussing a number of different lighting setups and techniques for coin photos in this guide.

After talking about this a bit on eBay's Coins & Paper Money discussion board, I've concluded no single lighting technique is "best." Each has its advantages and disadvantages. Some show small surface detail well. Others excel at showing luster or toning. In fact, a single eBay coin auction or listing could well use more than one lighting technique, allowing prospective buyers to properly evaluate the coin.

A Basic One-Light Setup

In most cases, a coin can be adequately shown with just one light sourcee. As already discussed, placement of a light source has a lot to do with how the coin will look, but in general, I think a light placed to one side and at a relatively low angle usually works best.

In the setup below, the light is at approximately a 30-degree angle to the coin. Notice that it is placed further away than the camera's lens. This helps keep stray light from getting into the optics and lowering contrast.
 


In all of the setups I am showing, I have my camera mounted on a photo copy stand, pointing downward at the coins. If you don't have such a copy stand, a small tripod would do. However, you will definitely need a firm camera support for maximum sharpness and to do your coins justice. If you will be shooting a lot of coins, I think a copy stand would be a good investment.

The light shown above is a single 150 watt tungsten bulb, mounted in a simple conical reflector to the left of the camera. Adjusting this light to different angles can give different effects. A very low angle will rake the light beam across the coin surface, making design edges, surface nicks and marks stand out sharply. A high angle will increase the reflective shine of the coin. However, this gain will come with some loss of contrast and detail.

The photo below was shot wth the light at approximately the angle shown above.



I'm not entirely happy with that shot, because the brightest areas, such as below Liberty's chin, are without detail. At the same time, the harshness of the light actually overemphasized a few small surface defects in darker areas. All in all, it's a serviceable photo, but it could be improved by diffusing or filtering the light. I'll discuss that in my next blog post.

How the Direction of Light Affects How a Coin Looks

If you check coin listings on eBay it quicly becomes clear that many sellers never think of their coins as individual sculptures, requiring different lighting approaches. There are many ways for light to affect the looks of a coin, but the most important one is the direction of the light.

At the very least, consider that that many coins contain faces or human figures. Would you light a person from beneath the chin or behind the head? Well, not someone you like, at least.

Let's take a look at that 1892 Morgan dollar again. In each of the following photos, the lighting is provided by a single diffuse tungsten light, at approximately a 45-degree angle to the face of the coin. The only thing different is the direction of the light.

First, with the light striking from the top, we have...



While that's not terrible and you can fairly well see the condition of the coin, I wouldn't advise lighting your spouse the same way.

Now, here's the Morgan lit from beneath, which I think is just plain ugly. Do not do this...



In fact, I can't think of any instance in which you might want such "Frankenstein" lighting.

And I think that lighting from behind the head just shows you were too lazy to turn the coin or the light around...



Of course, this does show off Liberty's cap and hair nicely.

On the other hand, I think that lighting the lady's face is the right thing to do (even if the light is coming from the left side in this case)...




You may not always be shooting a coin with a face, but I think this shows how much a good sense of direction can add to your presentation of a coin.

The second entry into this ongoing work in progress. You can find other entries in menu at the left side of the blog.

Using a Camera's Built-in Flash to Light Coins

Normally, I would warn strongly against using the built-in flash on a digital camera as a light source for eBay photos. In general, such a small light source, placed so close to the camera lens, produces a flat, unflattering effect. However, coins are a bit different than most items.

For one thing, because extreme close-ups are required for coins, a built-in flash can be at a significantly different angle than the lens. This reduces the flattening effect, especially if the camera has a pop-up flash, which further increases the difference in angles.

On the other hand, most digital cameras do not do a good job of throttling down a flash for such short-range shooting. This leads to severe overexposure, especially of a highly reflective coin. Also, because of the short distance, the light fall-off from one side of the coin to the other can be too stark, leading to extremely bright and extremely dark areas.

You may have had better luck, but the shot below of an 1892 Morgan dollar is the best I've been able to do with a built-in flash.



This was taken with a very capable camera (a Canon Digital Rebel). In order to keep from overwhelming the coin with the flash, I shot in manual exposure mode, setting a very small  lens aperture. This gave me a nice, sharp photo, but that's about the only good thing about it. As you can see, the coin is a bit too bright at the top and much too dark at the bottom. Worse, the harshness of the flash overemphasizes every tiny detail in the coin. Believe me, this coin looks better than this in real life, as you'll see in the next section.

A Work in Progress

I'm working on a new guide about coin photography to add to my ongoing series of guides on eBay photography (to be found at www.camerajim.com).  I'm going to use this blog as a sort of notebook as I put the guide together. Since the blog is posted chronologically, you should read these posts in reverse order as I post them.

While I know quite a bit about photography, I don't know much about coins.  I would appreciate any comments or corrections you could offer about this work in progress.

The Coin as a Photo Subject

Before I get into the different ways to photograph a coin, I'd like you to think about the coin as a photo subject. The mistake I think many people make when photographing coins is to think of them as flat objects. That is far from the truth. In fact, a coin is a small three-dimensional sculpture, with depth, dimension and texture. To complicate matters, this sculpture is made of a material which reflects light in ways  not often encountered with most objects.

This is why I think it's a mistake to use a scanner to illustrate coins for sale on eBay. A scanner is optimized to reproduce flat objects. While it may give a sharp, recognizable image, a scanner can't do justice to the look and feel of a good coin.

For this subject, you need a capable camera, proper lighting and good technique.

Selecting a Camera and Camera Basics

Throughout this guide, I will assume you have a good digital camera, but you could take your photos with a film camera instead of a digital camera. Your photo processor can then give you a CD with digital images which can be uploaded to your computer. However, for eBay use, it is much more economical and convenient to shoot digitally.

If you need more help with selecting a digital camera, you can find some general guidelines and a few model recommendations in this section of my eBay Photography Guide...

Selecting a Camera for eBay Photos

Before proceeding, I'd also suggest you read this section about camera controls and settings...

Cameras Controls and Settings for eBay Photography