Interesting and potentially very useful photos from another forum 0

[RWB]

The following link takes you to a neat thread, "Results with new camera and objective lens," on PCGS concerning high quality detail images accomplished by stacking. There are a lot of uses for these. (They were initially popularized by Dr. Mark Goodman in his book on coin photography.)

https://forums.collectors.com/discussion/1089671/results-with-new-camera-and-objective-lens

There is one false claim in the original post:

"I was also able to prove that a 1942 Pattern Cent was in fact a high-relief strike, the only one known for the Lincoln Cent series. To do these renderings, I need to take images at small increments, typically 10 micrometers. This gives me the ability to measure the heights of the features, and I was able to show that the Pattern Cent had higher relief than either the Business Strike or Proof from same year. That study was published in the Numismatist a few years back."

The claim is false because selection and layer separation are manually approximated; that is, not accurately measured by standard technology. Thus, the claimed results are not repeatable. Also, all of the versions come from the same hub, which cannot produce both normal and high relief. A standard profilometer (such as a Keyence 3D) can make such measurements and provide empirical results, but when challenged several years ago this was refused.  (PS: The coin in question is NOT a PATTERN - it is an experimental piece correctly described and illustrated in my book of WW-II Pattern and Experimental Pieces.)

 

Edited March 30, 2023 by RWB

[Henri Charriere]

If there were even a remote possibility of hearing a reasonable explanation to the reply as heretofore presented by @RWB I would certainly be interested in hearing it.

[RWB]

Stacking sharp, high resolution images can be very useful in identifying repunched characters and the oblique version creates an interesting way to improve visual examination of field-to-relief intersections. But, proof comes from empirical measurements, not someone "assuming" one image is exactly 10 micrometers different in altitude from another. This is simply identifies an absences of scientific rigor on the part of the camera user and any sponsoring entity.

(PS: The relief of every die made from the same hub are not necessarily identical. Slight difference in metal hardness, pressure, metal flow, etc. cause small variations. I suggest, but have not tested, that if one takes 25 new 1942-P cents all from the same hub, they will all have differing relief. The range might easily encompass sufficient to include any claims of discovery of a "high relief" coin from normal hub. It is physically impossible.)

[olympicsos]

On 3/30/2023 at 5:43 PM, RWB said:

Stacking sharp, high resolution images can be very useful in identifying repunched characters and the oblique version creates an interesting way to improve visual examination of field-to-relief intersections. But, proof comes from empirical measurements, not someone "assuming" one image is exactly 10 micrometers different in altitude from another. This is simply identifies an absences of scientific rigor on the part of the camera user and any sponsoring entity.

(PS: The relief of every die made from the same hub are not necessarily identical. Slight difference in metal hardness, pressure, metal flow, etc. cause small variations. I suggest, but have not tested, that if one takes 25 new 1942-P cents all from the same hub, they will all have differing relief. The range might easily encompass sufficient to include any claims of discovery of a "high relief" coin from normal hub. It is physically impossible.)

But I will say that a Lincoln Cent obverse in 1968 appears to have a higher relief than a 1916 Lincoln Cent obverse despite it being from the same master hub.

Edited March 31, 2023 by olympicsos

[RWB]

1968 cents originated with a very badly deteriorated master die made in 1916 (not hub) that had been in use far too long. A new master die was first used in 1969. The 1942-dated hub was used to make about half of that year's working dies, and a different hub for the remainder. It is impossible to make coins of normal and high relief from the same hub.

Edited March 31, 2023 by RWB