Quiz: Why is COLOR important for authentication? 1 1

[Henri Charriere]

1 hour ago, VKurtB said:

I apologize. I thought it was the demise of circulating silver that caused you such dismay, not the advent of pieces “with funny colored edges”. Now a large portion of the world has not gone our way, opting instead for simple plating. How does that option tickle your fancy? Think carefully. It has implications for reeded edge coins. Plated ones often peel.
 

Even the U.K. fundamentally changed the shape and size of their 5p and 10p pieces and their reeds before adopting plated steel for those denominations. The U.S. obsession for NOT changing the size and shape of our circulating coinage has its own consequences. 

Whew!  Now I can sleep again.  Ever since that Forum dust-up with RR2020 and that pristine edge, edge is just another four-letter word.  Coins are, or perhaps once were, irrevocably wedded to the vending machine industry.

[VKurtB]

2 minutes ago, Quintus Arrius said:

Whew!  Now I can sleep again.  Ever since that Forum dust-up with RR2020 and that pristine edge, edge is just another four-letter word.  Coins are, or perhaps once were, irrevocably wedded to the vending machine industry.

Yup, and far much more so here than anywhere else. The U.K. seems to obsolete coinage as often as some people change their underwear.

[Henri Charriere]

3 hours ago, VKurtB said:

Yup, and far much more so here than anywhere else. The U.K. seems to obsolete coinage as often as some people change their underwear.

To think I once had a 1797 British two-pence cartwheel that had measurably more original mint luster than the one graded at MS-64, I saw on E-bay earlier today. Talk about why COLOR is important!  I love copper and hefty coins and that giant was a beautiful gem!

[Insider]

On 9/3/2020 at 3:55 PM, Moxie15 said:

question for @Insider

If florescent light is good for viewing why is that I have such trouble seeing copper through a glass under florescent lighting?

Florescent light is best used for counterfeit detection and SEEING THE FIRST SIGNS OF LOSS OF ORIGINAL SURFACE on any coinage metal.  In order to do this with a hand lens, it is best to learn the difference between friction wear, weak strike, and "roll" compression using a stereo microscope + florescent light.  Once you learn the difference, you'll be able to see it with a hand lens.  Copper is more difficult than silver or gold and nickel is even harder as Nickel has the least color change with wear. 

I cannot count the number of times I've watched professional numismatists go back and forth about a characteristic on a coin that me or a person with the experience I recommend above can ID CORRECTLY in 2 seconds or less!  

[RWB]

12 hours ago, Insider said:

Florescent light is best used for counterfeit detection and SEEING THE FIRST SIGNS OF LOSS OF ORIGINAL SURFACE on any coinage metal.  In order to do this with a hand lens, it is best to learn the difference between friction wear, weak strike, and "roll" compression using a stereo microscope + florescent light.  Once you learn the difference, you'll be able to see it with a hand lens.  Copper is more difficult than silver or gold and nickel is even harder as Nickel has the least color change with wear. 

I cannot count the number of times I've watched professional numismatists go back and forth about a characteristic on a coin that me or a person with the experience I recommend above can ID CORRECTLY in 2 seconds or less!  

What type of fluorescent light? Shape, type, wattage, etc.

Please explain why this is superior to other kinds of lighting? (Not just "I can see it better" but why you can see it better. There must be a physical reason(s).)

[VKurtB]

1 hour ago, RWB said:

What type of fluorescent light? Shape, type, wattage, etc.

Please explain why this is superior to other kinds of lighting? (Not just "I can see it better" but why you can see it better. There must be a physical reason(s).)

Oh Roger, I tried that angle already. Skip won’t bite. He’s a “true believer” who doesn’t think “why” matters. He can flush a toilet. Woo hoo! Yippee! The ANA says incandescent, 100 watts, three feet away. End of story. The ANA’s Standards even go on to outright DISMISS fluorescent light as valuable. But hey, this hobby is nothing if not a “cult of personalities”.

Edited September 7, 2020 by VKurtB

[Zebo]

11 minutes ago, VKurtB said:

Oh Roger, I tried that angle already. Skip won’t bite. He’s a “true believer” who doesn’t think “why” matters. He can flush a toilet. Woo hoo! Yippee! The ANA says incandescent, 100 watts, three feet away. End of story. The ANA’s Standards even go on to outright DISMISS fluorescent light as valuable. But hey, this hobby is nothing if not a “cult of personalities”.

So without going through the entire thread, what do you believe is the best and what is an adequate light source? I just blew two fairly expensive bulbs - so you may influence me on my next purchase.

thanks

[VKurtB]

Now granted, Skip may view “authentication” and grading as two different activities, and I suppose they are. But here are some quotes from the Official American Numismatic Association Grading Standards for United States Coins, 7th Edition.

“The same coin can have a different appearance depending upon lighting conditions and also the amount of magnification used to examine it.

For purposes of standardization, we recommend that a magnifying glass of at least three (3x) to seven power (7x) be used. This is sufficient to reveal all the differences and peculiarities necessary to grade the coin accurately.”

Editorial comment (mine): NOT 10x and certainly not 30x. Although... (continuing on)

”You may wish to keep a stronger magnifying glass on hand, however, for examination of minute die details. It is also desirable to use a magnifying glass of sufficient width so that a fairly large amount of the coin’s surface can be studied at one time.”

 

More on lighting to come below.  

[VKurtB]

7 minutes ago, Zebo said:

So without going through the entire thread, what do you believe is the best and what is an adequate light source? I just blew two fairly expensive bulbs - so you may influence me on my next purchase.

thanks

To quickly answer your specific question, politicians are RIGHT NOW (including one hunkering down in the First State) attempting to make literally ILLEGAL the best light source.

[VKurtB]

More:

”The lighting we recommend for grading is a 100-watt incandescent light bulb approximately three feet from the coin (or a 50-watt bulb at an appropriately closer distance, or other equivalents). Incandescent light furnishes a pinpoint light source and enables surface characteristics to be studied in more detail. “Tensor” type lamps using halogen bulbs, popular at coin conventions, furnish a high intensity pinpoint light source and are often used for grading, although some numismatists find that they are uncomfortable to use, and they may be dangerous to the eyes (check with an ophthalmologist before making intense use of this light source).”

 

Again, more to follow, including the coup de grace.

[VKurtB]

The coup de grace:

”Warning: Fluorescent light, which spreads illumination from a diffused origin, is apt to conceal minute differences and camouflage certain defects, and should not be used.“

This article was written by Q. David Bowers and edited by Kenneth Bressett. But yeah, I’m the “troll” here. Get a life. Bowers and Bressett versus Yippee Skippy. I choose the former.

[VKurtB]

Sorry Skip, I reached my breaking point over your disinformation. It happens.

[RWB]

Multiple factors affect lighting for close examination (and photography). In summary these are: incident background, ambient lighting, source spectrum, intensity, source scale ratio, angle of incidence.

Incident background  -  This is the color and brightness of the area within your field of view behind the coin being examined. This should be 18% reflectance neutral gray. A 90% white background can be used if it is not too close to the coin.

Ambient lighting – General lighting in the examination room. Preferably indirect, low intensity sufficient for taking notes but not competing in brightness with the examination light. No ceiling fluorescent, vapor or other lights.

Spectrum – 5500K daylight, nearly flat energy curve. Modern “white” and adjustable LEDs are preferred.

Intensity -  Approximately 1,700 lumens. (This is the radiant flux after allowance for human vision system.)

Source scale ratio – This is commonly approximated as the ratio between source diameter and a standard working distance of 500mm between coin and light. A 10mm LED source at 500mm distance has a ratio of 0.02; if the light source is 20mm the ratio would be 0.04. As the ratio increases the source becomes broader and more diffuse, eventually resulting in wiping out of most detail. Laboratory preference in artifact examination and restoration is a ratio of 0.02 to 0.08. For coins, I prefer 0.04 as a compromise of contrast and shadow detail. (Known as angular size in more precise circumstances.)

Angle of incidence – Variable as coin is tilted and rotated to better discern surface.

The type, color and size of reflector holding the light source is also a factor and will somewhat alter the effects of lighting...generally making it "softer" and "warmer."

 

Edited September 7, 2020 by RWB

[VKurtB]

Particularly as it pertains to photography, that is all perfect. Examination connotes lots of things.

[Zebo]

1 hour ago, VKurtB said:

More:

”The lighting we recommend for grading is a 100-watt incandescent light bulb approximately three feet from the coin (or a 50-watt bulb at an appropriately closer distance, or other equivalents). Incandescent light furnishes a pinpoint light source and enables surface characteristics to be studied in more detail. “Tensor” type lamps using halogen bulbs, popular at coin conventions, furnish a high intensity pinpoint light source and are often used for grading, although some numismatists find that they are uncomfortable to use, and they may be dangerous to the eyes (check with an ophthalmologist before making intense use of this light source).”

 

Again, more to follow, including the coup de grace.

That is what I've always heard 75-100 watt incadesent as long as you remain constant.

[VKurtB]

8 minutes ago, Zebo said:

That is what I've always heard 75-100 watt incadesent as long as you remain constant.

You heard right. Ignore this verkokte fluorescent garbage being spewed here. I’m sorry folks, but now I’m pi$$ed off.

Edited September 7, 2020 by VKurtB

[Henri Charriere]

47 minutes ago, VKurtB said:

Particularly as it pertains to photography, that is all perfect. Examination connotes lots of things.

Without discounting anything RWB has said, because I simply do not know, my personal experience coincides with yours. I know saying so will forever cripple our cordial relationship but I AGREE WITH YOU 100%. Your explanation exudes that otherwise indescribable quality best described in the French as je ne sais quoi.

[Zebo]

1 hour ago, RWB said:

5500K daylight, nearly flat energy curve. Modern “white” and adjustable LEDs are preferred.

This is what I had been using - until both bulbs blew. Oops - I gotta run, my black market source with the incadesent lights just called. I wonder if they are Chinese knock offs!

Edited September 7, 2020 by Zebo

[VKurtB]

2 minutes ago, Zebo said:

This is what I had been using - until both bulbs blew. Oops - I gotta run, my black market source with the incadesent sustained called. I wonder if they are Chinese knock offs!

Not all LED lamps are created equal. Many are appropriate, but some are not. If you carefully follow RWB’s specs fully, you’ll do VERY well. If you nonchalant it and cut corners, you’ll suffer. 

[Zebo]

Just now, VKurtB said:

Not all LED lamps are created equal. Many are appropriate, but some are not. If you carefully follow RWB’s specs fully, you’ll do VERY well. If you nonchalant it and cut corners, you’ll suffer. 

I believe that I took my original setup for coin photography out of Goodman's book. I'll have to go back and check. Either way - good discussion along with some heat and some laughs.

[Henri Charriere]

2 minutes ago, Zebo said:

This is what I had been using - until both bulbs blew. Oops - I gotta run, my black market source with the incadesent sustained called. I wonder if they are Chinese knock offs!

The response I got from the proprietor of one store who sold me incandescents that were dead, blew right away, or lasted only a few hours or days is:  "DIS 99-CENT ST'AWE! WHA U EXPECK?" All such bulbs from China and Hungary are congenitally defective.

[VKurtB]

1 minute ago, Quintus Arrius said:

The response I got from the proprietor of one store who sold me incandescents that were dead, blew right away, or lasted only a few hours or days is:  "DIS 99-CENT ST'AWE! WHA U EXPECK?" All such bulbs from China and Hungary are congenitally defective.

I am a HUGE fan of phonetic spelling. Outstanding!

[RWB]

Among the best LED light arrays for document copy work at these:

SpectroLED Essential Bi-Color LED and Daylight LED lights. Bi-Color have color temperatures of 3200K and 5600K; daylight has only 5600K. Very low heat, and stable color over life of LED. Very low power drain but allows copy exposures of f-16 at 1/125-sec ISO 200. Look for similar specifications for 2- and 4-LED arrays for coin examination.

 

[Insider]

4 hours ago, RWB said:

What type of fluorescent light? Shape, type, wattage, etc.

Please explain why this is superior to other kinds of lighting? (Not just "I can see it better" but why you can see it better. There must be a physical reason(s).)

See if this reply makes sense to you:  I don't know anything about microwave ovens.  Nothing about wattage, microwaves, or how they work.  I have heard that the microwaves agitate something inside of things.  I once read they were used to make our diplomats sick.  However, I do know how to set the timer (even the clock) on the microwave oven in my kitchen and the results are outstanding.  Therefore, I don't need to know the answer to any of your questions about florescent light.  However, I am anxious to learn something from you.  

[VKurtB]

22 minutes ago, Insider said:

See if this reply makes sense to you:  I don't know anything about microwave ovens.  Nothing about wattage, microwaves, or how they work.  I have heard that the microwaves agitate something inside of things.  I once read they were used to make our diplomats sick.  However, I do know how to set the timer (even the clock) on the microwave oven in my kitchen and the results are outstanding.  Therefore, I don't need to know the answer to any of your questions about florescent light.  However, I am anxious to learn something from you.  

All that indicates to me is someone bereft of intellectual or scientific rigor, also known as intellectually lazy. It also is indicative of someone whose articles I feel I can safely ignore without missing anything of import. We have quite enough anti-intellectualism in this hobby and on this message board already, IN MY OPINION. Explain why or be not taken seriously. Even when I disagree vehemently with @RWB, he at least makes a case, and I respect that.

Edited September 7, 2020 by VKurtB

[Insider]

3 hours ago, VKurtB said:

Oh Roger, I tried that angle already. Skip won’t bite. He’s a “true believer” who doesn’t think “why” matters. He can flush a toilet. Woo hoo! Yippee! The ANA says incandescent, 100 watts, three feet away. End of story. The ANA’s Standards even go on to outright DISMISS fluorescent light as valuable. But hey, this hobby is nothing if not a “cult of personalities”.

Actually the ANA has no standards that are meaningful and followed by the majority of professional numismatists.  It has been that way for decades.  That is why PCGS and later NGC came into being. 

BTW, one or two coin courses does not make you a professional numismatist.  It does give you bragging rights over the newbies and a piece of paper to hang on your wall.  You do seem to know something about light and photography.  When you are posting on those subjects, your opinions are useful.

Furthermore, II don't think you have ever used a stereo microscope WITH FLORESCENT LIGHT!   The ANA course uses incandescent.  So, until you try it, you will never be a believer and your posts about how bad florescent light is are worthless, ignorant, misinformation.  

If I can convince well-known folks who shall remain nameless that they can see friction on a coin in seconds using that type of light, that's all that matters to me.  The fact that all wlll continue to promote incandescent light does not matter.  AU coins are considered MS today.  They don't wish to rock the boat.  Can you blame them? 

It is really simple.  The line between MS and AU, original or not, is clearly and easily defined with one type of light.  For some folks it matters.  For most it does not.   The people I respect are those who can look at a coin, describe everything on it, and then tell me why they choose to ignore much of what they can see.  That is the game knowledgeable numismatists play.  I tell the story of one of the biggest dealers and best graders in the country who insisted on buying an AU 1917 Type 1 SLQ from me because he knew it was a commercial gem MS-65 at a time when MS-70 was the only higher grade.  HE KNEW the coin was an AU.  I also told him two times it was just an AU and not good enough for him.  He bought it.     

[VKurtB]

No, my stereo microscope came with LED’s individually selectable by quadrant, but I hate it. I usually use it under diffuse window light, and I never (unless I lend my camera and forget to reset it) use either Auto White Balance nor any white balance setting other than taking a reading off a 18% gray card or 90% white one, just like RWB does. You’re no better than that @GDJMSP clown over at CoinTalk. You both refuse to remain current and live in your ignorant 30-40 year old bubble. “Troll” enough for you?

Edited September 7, 2020 by VKurtB

[Insider]

3 hours ago, VKurtB said:

 

Posted 2 hours ago

Now granted, Skip may view “authentication” and grading as two different activities, and I suppose they are. [THEY ARE] But here are some quotes from the Official American Numismatic Association Grading Standards for United States Coins, 7th Edition.

“The same coin can have a different appearance depending upon lighting conditions and also the amount of magnification used to examine it."  [A 100% accurate and observable fact]

For purposes of standardization  [This was a great idea that failed] we recommend that a magnifying glass of at least three (3x) to seven power (7x) be used. [At one time it was 4X.  Then it went to 5X.  Now it seems 7X - higher than the TPGS is their "new standard."]  This is sufficient to reveal all the differences and peculiarities necessary to grade the coin accurately.”  [7X is great,  My scope is set at 7X and my main handlens is also 7X.  I find that most collectors use 10X - 14X]

Editorial comment (mine): NOT 10x and certainly not 30x. Although... (continuing on)

”You may wish to keep a stronger magnifying glass on hand, however, for examination of minute die details. It is also desirable to use a magnifying glass of sufficient width so that a fairly large amount of the coin’s surface can be studied at one time.”  [Unfortunately, the higher the power the smaller the viewing area, even my 10X Triplet is small.] 

 

More on lighting to come below.  

[Insider]

More:

”The lighting we recommend for grading is a 100-watt incandescent light bulb [This is 1/2 of a GREAT set up.  It lets you see marks and hairlines easily when you examine the coin properly  - tipping and rotating it at the same time] approximately three feet from the coin (or a 50-watt bulb at an appropriately closer distance, or other equivalents). Incandescent light furnishes a pinpoint light source and enables surface characteristics to be studied in more detail. “Tensor” type lamps using halogen bulbs [are terrible unless you cannot see in the first place!  They make it even harder to see friction as every Brilliant MS coin looks blast "gem" quality], popular at coin conventions, furnish a high intensity pinpoint light source and are often used for grading, although some numismatists find that they are uncomfortable to use, and they may be dangerous to the eyes (check with an ophthalmologist before making intense use of this light source).”

 

Again, more to follow, including the coup de grace.

 

I'll be waiting to read the coup de disgrace.  

[Insider]

3 hours ago, VKurtB said:

The coup de grace:

”Warning: Fluorescent light, which spreads illumination from a diffused origin, is apt to conceal minute differences and camouflage certain defects, and should not be used.“

This article was written by Q. David Bowers and edited by Kenneth Bressett. But yeah, I’m the “troll” here. Get a life. Bowers and Bressett versus Yippee Skippy. I choose the former.

What you don't seem to understand YET is that a person using TWO EYES - the normal way we see things, a stereo microscope set at 7X, and florescent light ("No defect can Hide from florescent light" a quote from the makers of three million dollar automobiles) can see EVERYTHING there is to see on a coin.   Furthermore, I'll guarantee that I have looked at more coins more closely in my short career than either of the two respected numismatists you mention.   Therefore, I respectfully disagree with both of them. 

Furthermore, while you don't count at all because you have never looked at a coin using a stereo microscope and florescent light, I do value your "parroting" defense of the status quo through the experiences of OTHERS!!