Suggestion - Would a standard reference grid make attribution easier?

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RogerB
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Suggestion - Would a standard reference grid make attribution easier?

Post by RogerB » Thu Oct 01, 2020 4:24 pm

A thought or question - Wouldn't all of the date position and mintmark position references be much easier to manage and check if they were always in relation to stable points on the portrait and eagle? The location and angle of an extended line connecting any two points on the central device is always the same. Relationships to denticles and other minor design elements varies.

Maybe a fixed reference grid anchored to central design points would be more useful....? Here's a very rough sample.
1881-S_RonH_VAM-1A_OBV-crop.jpg
1881-S_RonH_VAM-1A_OBV-crop.jpg (217.32 KiB) Viewed 715 times
The obverse grid is anchored by the vertical line of Liberty's throat and the corner of her eye. Since the grid is rectangular and scaled in even millimeters, changes in relative location and orientation of date, stars, etc. are much clearer than the present ad hoc approach.

The sample grid is not to scale - I recommend a 1 mm or 2 mm grid which would result in either 38 or 19 full squares across the coin.

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messydesk
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by messydesk » Thu Oct 01, 2020 5:08 pm

I'm not sure if a millimeter scale would work well, because that requires a user to be able to measure distances and absolute distances change with die wear. I know that these sorts of measurements are used to describe some things on bust halves, however.

For lateral date position, Alan has a system that describes the position of the left and right edges of the 1 relative to specific denticles that is more precise than simply saying near, normal, and far. He has standardized it across his die studies and others have picked up on it. Accuracy can be influenced by wear, of course.

Other date position components (height, slant) aren't precisely measured, but they aren't precisely specified, either.

The sort of thing that would help with attribution would be a mug book of date positions and mint mark positions, all photographed in the same conditions and registered with each other such that the non-moving references (denticles, bust tip, ribbon landmarks, DO in DOLLAR) are in fixed positions, as you describe with your proposal. This is where a grid would come in handy -- to do the image registration and scaling. @raynat3 did this with 83-O mint marks quite some time ago, and it is helpful.
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vampicker
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by vampicker » Thu Oct 01, 2020 5:37 pm

I've also seen this sort of thing before. Dr Mark Kimpton had done something similar to note die clash positions, but I think he abandoned it because of the die stage issue JB mentioned. A grid can be useful, but it has limits - mainly human error in the alignment.
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Flat-Chested
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by Flat-Chested » Thu Oct 01, 2020 6:32 pm

The middle of the "I" in RIB is not the exact top of the coin?

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messydesk
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by messydesk » Thu Oct 01, 2020 7:24 pm

Flat-Chested wrote:
Thu Oct 01, 2020 6:32 pm
The middle of the "I" in RIB is not the exact top of the coin?
Half-way between I and B.
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RogerB
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by RogerB » Thu Oct 01, 2020 7:48 pm

Only the central design elements are fixed. Denticles are not fixed in relation to the portrait and thus cannot be used for reliable positions.

As far as measuring distances, a grid or fixed reference has exactly the same limitations of user accuracy as anything else. The vertical sides of digits and letters and not perpendicular to the field, and that creates an ambiguous intersection - a problem for all coordinate/reference systems.

Die wear (aka "die state") has very limited effects on the central elements - portrait and eagle. The anchor points selected should be clear and unambiguous. For example, the two points I mentioned above are unaffected by die wear or extreme coin abrasion.

In any event, you folks are the users. I am merely an observer and thought something more stable and repeatable would be helpful - especially to newcomers.

colwillys
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by colwillys » Thu Oct 01, 2020 9:16 pm

Would centering the EAR work in the grid .

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vampicker
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by vampicker » Thu Oct 01, 2020 9:38 pm

RogerB wrote:
Thu Oct 01, 2020 7:48 pm
Only the central design elements are fixed. Denticles are not fixed in relation to the portrait and thus cannot be used for reliable positions..
Might want to double check that
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messydesk
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by messydesk » Thu Oct 01, 2020 10:24 pm

vampicker wrote:
Thu Oct 01, 2020 9:38 pm
RogerB wrote:
Thu Oct 01, 2020 7:48 pm
Only the central design elements are fixed. Denticles are not fixed in relation to the portrait and thus cannot be used for reliable positions..
Might want to double check that
Except for 1878 where there are hubs with denticles in a different position relative to the portrait.
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vampicker
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by vampicker » Thu Oct 01, 2020 11:00 pm

Yeah, but even then its consistent for all dies from that hub.
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LateDateMorganGuy
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by LateDateMorganGuy » Fri Oct 02, 2020 12:33 am

In all fairness, I did not create the DPIS (date placement indexing system) that I use for my die studies that MD references. I borrowed it from JR from his 89-CC series study. I may have refined it a bit, but that is irrelevant. I think JR may have borrowed the idea from researchers of other denominations, but JR can chime in on that.

One point to make is that research and ideas start somewhere, and can blossom by later researchers as the research continues. We can build upon each other so to speak.

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vampicker
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by vampicker » Fri Oct 02, 2020 12:42 am

Yeah, I adapted Howard Newcomb's scale for late date large cents
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RogerB
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by RogerB » Sat Oct 03, 2020 2:38 am

vampicker wrote:
Thu Oct 01, 2020 11:00 pm
Yeah, but even then its consistent for all dies from that hub.
A reference system should be uniformly applicable to ALL (or nearly all) of a specific design. A system locked to the portrait or eagle meets this criteria.

If you want to see how a locked reference system makes variety identification easier, look in my Saint-Gaudens Double Eagle book (available from Heritage Auctions). Reference lines are locked to the central design and this helps variations in date, monogram, and mintmark position/orientation "pop out."

But you folks can consider, use, ignore, or reject "outsider" ideas however you wish.

I have no more to say on this subject.

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vampicker
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by vampicker » Sat Oct 03, 2020 12:07 pm

That wasn't my point. and a grid might help. It's not the first time it's been suggested. As you know, there were several design changes in the Morgan series. This included the location of the denticles. I was pointing out that they are fixed among coins of the same specific design - i.e. the main run of dollars from mid-78 thru 1904. Indexing the date relative to the point of the bust and the denticles under it works well. Since I got it from an attribution guide from an unrelated series, it could be thought of as an 'outside' idea.
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HawkeEye
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by HawkeEye » Sat Oct 03, 2020 4:40 pm

It seems to me that this idea has merit. So long as there is something, in this case Liberty's bust, that can be referenced as a fixed point, then all other elements of the design can be described relative to this fixed item. I am not sure as to the reference scale, but anything can be measured from a fixed object.

For example, if the point of the neck of Liberty's bust is one reference point, and the topmost wheat colonel is another fixed point then the rotation of the obverse can be fixed. Once this is locked into a position it seems to me that all other design elements can be described as to distance, angle, etc.

I think this deserves more discussion.
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messydesk
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by messydesk » Sat Oct 03, 2020 5:19 pm

What would be interesting is a survey of attribution materials for all types where this sort of position comes into play. There are some that use absolute distances (date measurements and A-to-arrow measurements on bust halves), some that use relative distances (nearer to this than that), some that use subjective positions (high, low), some use custom scales (Grellman large cent date position scales), and those are of varying precision (VAM near-far date vs. counting fractional denticles or notation like LE3 RH4).

All of these are both used to describe what was seen and to attribute a coin. Those describing have to be able to be consistent and repeatable so that those attributing can use with confidence.

If I think of how describing with a coordinate system would work, I'd use one anchor point on the design and two on the movable object such that I could specify a triangle. I'll use date position as an example. The three vertices would be the tip of the bust, the bottom left corner of the base of the 1, and some fixed position on the last digit that would vary by date. The three angles of this triangle would be used to describe the date position. A user of this information would have to measure this on their coin. While this would have been out of the question 10 years ago, many people have digital cameras or microscopes capable of producing a usable picture for this task, and software to do the measuring of is available or could even be provided by the party specifying this attribution system. Scaling or rotating the image and being able to do precise distance measurements won't matter, since the angles are unchanged under scaling and rotation. The photo couldn't be taken at an angle, but this would be a requirement in order for it to be in focus. So the process for the attributor is take picture, click three points, and get a list of candidates given date position. Clicking the points could even be automated with AI, so you could be down to 1 click instead of 4. All of this would work, and would be repeatable by both the specifying and attributing parties, but the question remains as to whether or not it would be usable.
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RogerB
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by RogerB » Sat Oct 03, 2020 7:17 pm

Points on or within dates and inscriptions are useless in a fixed reference system. These are all subject to random modification from polishing, re-basining, re-punching/strengthening, edge chips and other mishaps.

Any connection between the central design element and a potentially moveable point will be useless - it produces only an unstable, relative position. Any coordinate system must be anchored to immovable points - exceptions will destroy its value and then you might as well give up have any kind of fully useful information. That is why maps have fixed coordinates; astronauts have a universal frame of reference; archeologists establish a uniform coordinate system near the beginning of digging.

If your hobby specialty cannot accept absolute anchor points for relative measurements, then there is nothing to discuss. But remember that new specialty hobbyists are trying to absorb a mature - maybe 'aged' - set of variety information and conventions. If those conventions are not clear, consistent and meaningful, they will be more likely to look elsewhere for their hobby gratification.

Technology has changed how and why certain things can be accomplished. My suggestion is to make use of it to simplify, organize and rationalize variety identification and reporting.

OK.....I've said too much. Will really stop on this topic this time! ;)

blh74
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by blh74 » Sun Oct 04, 2020 12:18 am

On one of my coins sent to LVA, had a collar clash. I mentioned the slanted date also. Leroy made it two Vams. One with and one without the collar clash. 1902 P VAM 29 and 29A. I don`t understand why this has to be so technical.

Mike7E
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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by Mike7E » Sun Oct 04, 2020 6:11 pm

The question of using a grid to better define features has several interesting aspects, including one that I have been working on. I too have been trying to find a way to better describe clashed dies to reduce the time spent searching each die set for a year. High, medium or low is not adequate, and seldom used.

Calculating clash location as a percentage from the neck/jaw juncture to the bust tip would greatly narrow a search. Clashes on the jaw side would generate a negative percent and those on the neck line would have a positive value. The values don’t have to be exact if we only want to narrow the searching to a few die sets for a year/mint group. I use a grid available in Corel PaintShop Pro 2020 but any good imaging software has this feature.

This method should not be subject to die state degradation as the distance from the jaw/neck juncture to the bust tip and a clash would change in a relative way. I’ve seen elongated die break lines at the bust tip but they don’t obscure the real bust tip when using good images.
If someone can figure out a way to list the information on one of the attribution guides and there are clash line pictures that also show the bust tip I can use my software and start the process for a few years.

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Re: Suggestion - Would a standard reference grid make attribution easier?

Post by iwillbenice » Sun Oct 04, 2020 6:32 pm

Why and what for?
For the green ones?
It does help for easy placement and would have to make the differences for other die years for central placement.
I like.

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