Help Me Optimize My Axial Coin Photography Setup

The focal distance or distance from smartphone lens to the coin is about 6" with the glass/mirror about halfway between the two in the original pictures.

In my adjusted setup, the focal length is about 10" and I placed the bottom end on top of a tuna can that is about 2" high. That allowed me to still place the glass about halfway between the lens and the coin and was able to adjust the angle of the glass to get the best picture possible. I used the tripod and the bluetooth trigger this time to get the camera fixed higher.

I think that there is a tradeoff here. Although my lighting appears better, seeing the stronger cartwheel, I think that the longer focal length costs in terms of detail as I can't manually focus the subject.

The Galaxy S20 has a digital zoom, not an optical zoom, which means as you get farther away from the coin you will lose resolution because you're basically cropping. I would try to get as close as possible to the coin that still allows you to focus adequately. You shouldn't have to change your light box setup.

Weren't you using a Canon SLR before? I would think you could get better photos with that camera and lens, using the same axial lighting setup.

If there is luster/cartwheel, it is a sign that the axial lighting is not as even as it should be. Axial lighting is extremely even, with light hitting every spot on the coin in a uniform way. Below is a coin picture taken with axial lighting:



It shows no luster whatsoever. Luster/cartwheel only shows up when there is contrast in lighting, i.e. the light is not even. The following picture shows the same coin, with axial lighting AND a low angle narrow light source (Ikea goose neck LED light ). The luster is brought out by the additional light, not axial lighting.



Typically the light source of axial lighting is a broad one, such as an LED panel, or a fluorescent tube. I guess the flashlight is just not wide enough to provide even axial lighting.

What is the purpose of using axial lighting on a white business strike coin anyway?

"The purpose is to provide a better photographic rendering of coins. "

Axial lighting is one of the many ways of lighting in coin photography. For some coins (coins with colorful toning, for example) and for certain purposes (show details of the coin), it probably is a "better" way. For those who wish to show a bright field on the coin, this is an easy way to achieve that purpose. But it is not always better, especially when it is used alone, all by itself. Axial lighting is an even, broad light source. As such, the photos would come out "flat", missing shadows which help create a 3-D effect. It cannot bring out the luster band(s) which is vital for business strikes like the Morgan dollar. Circulated coins would appear "lifeless" and bland under this light setup, as your Seated Liberty shows.

There is not general "better" lighting that fits all the coins and all the purposes. Lighting setup needs to match the coin and the purpose. More often than not, different methods of lighting are used in combination, such as axial lighting with direct lighting, as in the second photo in previous my post.

"Adjusting the lighting source is one variable to toggle, I suppose among many. I don't think the light source's field of illumination is an issue given how large the light source is in my compact setup. "

Here is a post that shows several setups of the axial light source: http://goccf.com/t/197120&SearchTerms=axial. For the one that uses a single Ikea LED light, a white screen is place in front to expand the size of the light source. I personally use an LED panel, which can adjust both the intensity and color temperature. Before, I used three diffused Ikea LED lights which took a lot of space. The unevenness of lighting on your Morgan may have two causes. One is that the axial lighting source is too narrow. The other is that the angle of the glass is not quite 45 degrees. I actually often take advantage of the different angles of the glass to achieve some special effect. In the photo below, I left a small dark area on the coin by adjusting the angle, just to create some contrast. All white sometimes can be boring.



I use two 5X7 picture frames connected by a friction hinge. It allows me to adjust the angle freely:

Here is an excellent description of coin luster and how it is created: https://blog.goldeneaglecoin.com/coin-mint-luster/ This is an illustration of the point made in the article, i.e., flow lines on the surface of a business strike coin:



Their reflections of light create luster.

In coin photography, luster is shown as a bright band or bands on the coin. In the linked article above, the slabbed Morgan dollar has two wide luster bands:



The photo below shows three luster bands:



Mark Goodman gives following illustrations of luster bands:



To create luster bands on the coin during the photo session, narrow, low angle light sources are needed. On your photo no such luster bands are visible.

I think I got it (what luster is)

Sorry, I thought I posted my co-axial lighting setup, but I did not and only asked questions. So, FWIW, here it is. Basically, it is a piece of glass at 45 degree angle, a 50W LED panel light with diffuser shining into the glass. But key part here is to block all other lights by using a tube around the coin so only lights coming straight down contributes to exposure.

rmpsrpms, blog is coming