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Imaging Coin Surfaces


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I'm trying out a new (for me) imaging technique that is giving promising results for showing details on coin surfaces. I finally got it set up to give just the right magnification to show Lincoln Cent date and MM in the full image field. Here's what the technique gives for my heavily-toned 57D that I use for most of my image comparisons:

 

57D20Money20Shot_01.jpg

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I think these stereoscopic pics are fantastic for studying the coin itself. You can see minor varieties, metal flows, wear patterns, and how toning/cleanings have affected the surfaces. But these are pics most cherished by real scholars of the coin. As a materials engineer, I love these pics. But if I were just a collector who cared only about beauty, these would be like seeing a model with her make up off.

 

Post more!

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That's a wonderful detail shot. Images like this are superb for studying varieties and errors. Can you tell us a bit about your technique and equipment?

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Fantastic detail. Can you post an image of the cent itself so we can compare color, toning, etc. Hove you thought about eliminating the dust? It is somewhat distracting. What is the line running through the 1 and into Lincoln's lapel? I too would like to hear more about your technique.

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I think this is what would be considered a "minor RPM", not strong enough to list. There are many of them out there with doubling showing on one or both serifs. When you send them in for attribution, they come back as "serifs only, too minor to list".

 

This is one of my favorite coins to image, and has by now been photographed literally thousands of times comparing lenses, techniques, lighting, etc. I don't know what the line is on the lapel, it runs across the surface at all topographies including the date so it could be a planchet flaw. As for the dust, I don't know what to do about it. I've tried blowing on it with compressed air but it's very very small and stuck to the surface. I have considered a quick acetone dip but until I started with this technique the dust particles were not even visible! Anyway, here's the overall image:

 

75_RO_AD_01-1.jpg

 

My technique for this shot was different from any of my previous. The setup is similar, with lens on bellows, but the lens is actually two lenses together: a Nikon 5X CF BD Plan "infinity objective" mounted on a Nikon 150mm EL-Nikkor acting as a "tube lens". Lighting is by a single LED, same as previous setup, but at a much lower angle to emphasize the surface detail. Here is a pic of the setup in action:

 

Img3266_01.jpg

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Nice set up.

 

Have you considered using the clone tool in Photoshop to remove dust. It takes careful steps to be sure you don't change the image and you don't have to get each speck.

 

I'm curious if you have tried to maintain the luster present in the larger image. You might want to filter the light source some to help.

 

Pretty coin and a great subject. I look forward to more efforts.

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I've never used photoshop so that will probably be my next frontier. I'm sure a lot can be done in photoshop to improve the images.

 

The first coin was a highly-toned specimen. I tried the technique on an untoned, highly lustrous 1956-D RPM#1 and the results show a lot higher contrast that makes the single light source and low angle more of an issue. Here is the result:

 

56DRPM1.jpg

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I've never used photoshop so that will probably be my next frontier.

 

 

You don't have to buy the full version of Photoshop unless you need professional power. I have been using Photoshop Elements 2 (which came free with a Canon DSLR I bought back in 2004) with wonderful results. I recently upgraded my old 2004 laptop and installed Photoshop Elements 9 which is quite amazing.

 

Adobe lets you try before you buy too.....

 

http://www.photoshop.com/products

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I posted the last image on CONECA's die variety forum, and BJ Neff suggested adding diffusion to reduce hotspotting. I have also been trading posts with SuperDave over at Coin Community Coin Photography forum, and ended up getting out my Bausch & Lomb MonoZoom7 to compare with the stacked Nikons. The increased diffusion helped reduce the contrast seen on the very lustrous surfaces, and the MZ7 eliminated the Chromatic Aberrations that the stacked Nikons were showing. Here is the result of the various improvements:

 

56DD-Diffused_01.jpg

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