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What to Consider with Coin Photography

Originally published on January 3 2017

Smart phones and tablets contain optics and software to capture adequate photographs but when it comes to high resolution imaging for numismatic retail business, more sophistication equipment, software and techniques are necessary. I'm sure that others believe they are experts on coin photography so today's topic is an explanation of the techniques employed at GFRC. The goal of this discussion is not to judge who has the best images or which photography process is superior. The GFRC process has been optimized over a period of 13 years and I'm still learning new tricks every week. 

To bring about high quality digital coin images, each step in the photography and imaging process must be optimized. If there is a weak link in the chain, then the overall chain strength is diminished. The same applies for digital imaging. I see the following parameters as being absolutely critical towards generating quality photographs:

- Lighting
- Camera settings and operation
- Digital Image processing techniques

Then one has to consider the item to be photographed. Raw coins are much easier to photograph than TPG holdered coins. The latest generation of PCGS and NGC edge view holders are very challenging due to new holder designs with multi angled plastic edges that will reflect light at unexpected angles.....

So let's start with Lighting. Lighting selection is a critical parameter as each lighting source option generates its own color bias during photography along with emphasizing or hiding defects on a coin's surface. I believe that natural sunlight is the best lighting source for generating images that most closely capture a coin's natural colors. Have you tried viewing coins under halogen, incandescent, fluorescent and natural lighting? Each lighting source produces different results. Therefore it is critical to decide early on which lighting source best fits your publishing needs. At GFRC, I believe in selling coins with beautiful original toning so natural lighting is selected. 

Next is the Camera. Camera technology continues to evolve with super Mega Pixel options. I don't pay much attention to the latest developments as I use an old camera dating back to a 2002 release; the Nikon CoolPix 995 with bayonet mount. This is a large solid camera that is easily mounted on a stereo microscope with adapter that slides over one of the lens pieces. A "photodome" is also available that mounts on the camera and provides a simple but elegant solution for "setting up" the photography bench where ever bright sunlight is available. The "photodome" solves many problems including the proper focal length between coin and camera, eliminating lighting source shadowing and providing portability. Much more expensive photography benches are common with multiple lightning sources and a stand mounted camera. These bench's are not portable (they remind me of the old time audiophile component racks) and have their limitations though producing incredible images. PCGS TruView is an example of a sophisticated bench mounted system with special lighting sources.

Camera Operation: To capture the best possible images in terms of natural contrast and colors, my rule of thumb is F-Stop > 7.0 and Shutter Speed at 1/500 sec. Today's blog will not go into F-stop or shutter speed explanations....you can Google those topics at your convenience. The best possible image contrast is captured at the highest F-Stop possible in conjunction with the fastest shutter speed. Too much light exposure eliminates (washes out) the delicate details of a high quality coin. 

Image Processing: Everyone has their favorite image processing software so use the one you are most comfortable with. But always work with TIFF formatted files when processing images. The JPEG format is ideal for publishing due to its compressed format and small file size but is lousy format for image processing but has considerable loss of delicate image details due to compression at each image processing step. You must use TIFF regardless of large file sizes during image processing. So take that fresh camera image and immediately save as a TIFF and when done, save as a JPEG. 

Image processing has the following steps: 1) save as a TIFF, 2) rotational alignment, 3) RGB color compensation for lighting and camera bias, 4) contrast and brightness tuning to exactly match the coin in hand, 5) cropping in the white background, 6) resizing to standard website presentation size and 7) saving from TIFF to JPEG format. Within these seven steps, there are lots of subtle tricks that I have acquired over the years...experiment and decide what produces the best results for your needs.

TPG Holder Impact: Here is the GFRC list of rank ordered TPG holders from easy to just plain difficult. The white insert and early quality plastic on NGC Fatty holders make them ideal for photography along with ANACS Old White Holders. Today's cheap plastic holders, that are so prone to wear, and edge view insert make photography so much more challenging, especially for halves and dollar sized coins.
Best Rank Ordered: NGC Fatty, ANACS Old White Holder, PCGS Rattler, NGC Standard Insert, PCGS Old Green Holder, PCGS Standard Insert.
Worst Rank Ordered: NGC Edge View, PCGS Edge View