Quiz: Why is COLOR important for authentication? 1 1

[Insider]

Why is color important for coin authentication?

If you were examining a copper coin as this (10X) and saw lead colored areas what would come to mind?

 

 

 

 

[Moxie15]

I do not think I have ever seen lead color on a copper coin. I am guessing that is a copper plated zinc or some sort of jewler's metal

[RWB]

The photo looks too green - as if it were taken under fluorescent light. One cannot get accurate color using fluorescent lights - the spectrum is incomplete and highly concentrated in the green band. I don't see any lead gray color. What am I missing?

[Insider]

Everyone should see black, green, gray, and orange-brown in the image.  Otherwise, posting about an off-color, out of focus image ADDS NOTHING to this discussion.

Examining coins out in the "wild" is often done under poor lighting conditions.  I advise everyone to practice viewing coins in good and poor environments using several different types of light including sunlight.   Furthermore, I suggest folks have their vision checked.  Many collectors, especially men, suffer from color blindness making it hard to see changes of color. 

For added points on the quiz: What does the color green indicate on copper coins? 

 

Edited August 31, 2020 by Insider

[physics-fan3.14]

Green on copper: verdigris or corrosion. 

Lead: either solder (ex-jewelry) or possibly some remnant of a counterfeiting process. 

[Just Bob]

My first thought was corrosion, due to environmental conditions. I doubt I would have recognized the presence of lead from the picture.

[Alex in PA.]

I want to also say environmental but I think physics-fan3.14 may have a point.  I will hazard a guess that it is solder.

And thanks for bringing back your quiz.  They are both interesting and educational.

Edited August 31, 2020 by Alex in PA.

[RWB]

My LED monitor is calibrated to Photoshop. All the colors in the OP's kind of fuzzy photo have green contamination. Guess I'll check my glasses....just 'cause I use old Coke bottles for lenses....?

Tried adjusting the color and density assuming the holder is "white," but there's too much contamination and pixel noise to get it right. [The upper L should look gray against the message board white background.] Sorry.

 

Edited September 1, 2020 by RWB

[Insider]

This is a color change that is easier to see.  It is not due to the same cause; however, the answer is the same.  What do you think of when you see a color change in the silver-gray range on a copper coin?  

[physics-fan3.14]

Insider - I bet if you showed us a picture of the whole coin, many more people would get the answer easily. 

The pic on the nose almost looks like its a lead core with copper plating which is faking off. Unusual, unless its a rare date and an old counterfeit. The first pics looked like lead encrustations. However, the details here look soft and mushy. 

I'm also not sure what to make of the fields in front of her nose in these last pics. 

[RWB]

Sorry, but without correctly daylight balanced color, reliable color identification is nearly impossible.

:(

Edited September 1, 2020 by RWB

[Henri Charriere]

22 hours ago, Insider said:

For added points on the quiz: What does the color green indicate on copper coins? 

 

Chlorophyll?  Nope.  How does a "pistachio patina" sound?  It's nothing a dash of old-fashioned white vinegar can't solve.  And for those hard to remove stubborn stains, try Brillo with Ajax.  I have an old Sacagawea worn down to a smooth planchet a major TPGS refused to assign the rarely bestowed Poor-O (Zero) grade on the grounds that the date -- despite my compelling before and after photographs -- was indecipherable.

Edited September 1, 2020 by Quintus Arrius
Correct misspelling

[Insider]

14 hours ago, RWB said:

Sorry, but without correctly daylight balanced color, reliable color identification is nearly impossible.

Very sad.  I though a numismatist of your stature would add something useful as this poster has: "The pic on the nose almost looks like its a lead core with copper plating which is faking off. Unusual, unless its a rare date and an old counterfeit. The first pics looked like lead encrustations. However, the details here look soft and mushy." 

So far, we have a copper coin with green/black corrosion spots and areas of gray,  The image in the OP is fuzzy and out of focus.  That makes it almost impossible to tell if the color change to gray is on the copper surface or under it.   My second image is sharp.  A member saw a silver-gray color where the copper surface flaked off.  Since the quiz is about the change of color and what it might indicate, the authentically of the coins that I imaged is not important.  What is important is being able to see a different color on a coin.  Then we can see why it is there.  

So, what could cause a silver-gray color on a copper coin?  There are two main reasons and both have been express by one member.  Now, be a detective and explain the thought process for us that he may have gone through.  Physics-fan can answer later if he wishes but hopefully a few others will try first.   

Edited September 1, 2020 by Insider

[Henri Charriere]

I am in an unaccountably mischievous mood so I am going to hew toward First Impressions Count which in this case suggests without a date, or any other meaningful clews (which, to me, are purposeful omissions) this may very well be nothing more than a coprolitic deposit of unknown origin.  And to my many detractors who reject such a diagnosis and demand a more conventional explanation, I defer to our resident expert, Ratzie33, who is well-versed on such Frankensteinian matters. But wouldn't that be like finding a Ford Model T in King Tut's tomb?  There is no accounting for personal taste. 😀😉 Do have a great day, coin lovers!

[Insider]

 

 

I'm providing this image for our visually impaired members.  What number do you see?

[Henri Charriere]

9 minutes ago, Insider said:

 

 

I'm providing this image for our visually impaired members.  What number do you see?

I see a six, but I cheated. I viewed it cross-eyed.

[RWB]

1 hour ago, Insider said:

Very sad.  I though a numismatist of your stature would add something useful as this poster has: "The pic on the nose almost looks like its a lead core with copper plating which is faking off. Unusual, unless its a rare date and an old counterfeit. The first pics looked like lead encrustations. However, the details here look soft and mushy." 

So far, we have a copper coin with green/black corrosion spots and areas of gray,  The image in the OP is fuzzy and out of focus.  That makes it almost impossible to tell if the color change to gray is on the copper surface or under it.   My second image is sharp.  A member saw a silver-gray color where the copper surface flaked off.  Since the quiz is about the change of color and what it might indicate, the authentically of the coins that I imaged is not important.  What is important is being able to see a different color on a coin.  Then we can see why it is there.  

So, what could cause a silver-gray color on a copper coin?  There are two main reasons and both have been express by one member.  Now, be a detective and explain the thought process for us that he may have gone through.  Physics-fan can answer later if he wishes but hopefully a few others will try first.   

The original photo is, in my opinion, useless for making a determination about color or much of anything else. The second photo is better, but the color balance is obviously incorrect. Again, this makes it useless. That's all I can contribute.

Edited September 1, 2020 by RWB

[Insider]

14 minutes ago, RWB said:

The original photo is, in my opinion, useless for making a determination about color or much of anything else. The second photo is better, but the color balance is obviously incorrect. Again, this makes it useless. That's all I can contribute.

Thank you.  Read the post from Physics-fan.  He covered much of it.   BTW, do you see a number in the circle of dots I posted?  I've been told that this particular circle of color is one of the most commonly missed in the usual test.

Apparently, more women are colorblind than men.  This one also gives lots of folks trouble. 

 

  

[Insider]

Quiz answer tonight.

[Henri Charriere]

14 minutes ago, Insider said:

Thank you.  Read the post from Physics-fan.  He covered much of it.   BTW, do you see a number in the circle of dots I posted?  I've been told that this particular circle of color is one of the most commonly missed in the usual test.

Apparently, more women are colorblind than men.  This one also gives lots of folks trouble. 

 

  

Anyone, numismatist or not, who fails to discern the number eight -- clear as day here --

 

17 minutes ago, Insider said:

 

 

  

deserves to have his driver license revoked.

[VKurtB]

15 minutes ago, Quintus Arrius said:

Anyone, numismatist or not, who fails to discern the number eight -- clear as day here --

 

deserves to have his driver license revoked.

Come on now. I have now viewed these color blindness circles on a cheap phone, a really new high end phone, and a somewhat cheap computer monitor. They look radically different on each. What you see depends on the phosphors on your device every bit as much as your eyesight. These color blindness patches are designed to be used on a printed page with non-standard inks that are spot colors, not process CMYK color, and WORSE YET, not RGB additive color. Their use here is pointless. 

Edited September 1, 2020 by VKurtB

[Henri Charriere]

2 minutes ago, VKurtB said:

Come on now. I have now viewed these color blindness circles on a cheap phone, a really new high end phone, and a somewhat cheap computer monitor. They look radically different on each. What you see depends on the phosphors on your device every bit as much as your eyesight. These color blindness patches are designed to be used on a printed page with non-standard inks that are spot colors, not process CMYK color. Their use here is pointless. 

I was kind of hoping you would be like the guy in the Geico commercial who, when shown his likeness by the lady painting his portrait with the outsized bill, simply responded: "I don't see it." Phosphors?  Please!

[VKurtB]

6 minutes ago, Quintus Arrius said:

I was kind of hoping you would be like the guy in the Geico commercial who, when shown his likeness by the lady painting his portrait with the outsized bill, simply responded: "I don't see it." Phosphors?  Please!

Where is the D-o-u-c-h-e University where you got your degree?

Edited September 1, 2020 by VKurtB

[Alex in PA.]

[Henri Charriere]

Remember that book, All I really need to

15 minutes ago, Alex in PA. said:

Maybe, Alex, maybe. I hope I do not offend anyone but I am in a wonderful mood!  And the really sad part is there is nothing anyone can say or do to dampen my enthusiasm.  My love and respect for everyone on this Forum is unconditional.

15 minutes ago, Alex in PA. said:

 know I learned in kindergarten? As I am fond of saying I graduated in the top 90% of the Class of 1963, Magnum crumb laudanum, the William Sydney Mount school (P.S. 174) in the Crescents of Rego Park, Queens, City of New York. 

[VKurtB]

5 minutes ago, Quintus Arrius said:

Remember that book, All I really need to

Maybe, Alex, maybe. I hope I do not offend anyone but I am in a wonderful mood!  And the really sad part is there is nothing anyone can say or do to dampen my enthusiasm.  My love and respect for everyone on this Forum is unconditional.

 know I learned in kindergarten? As I am fond of saying I graduated in the top 90% of the Class of 1963, Magnum crumb laudanum, the William Sydney Mount school (P.S. 174) in the Crescents of Rego Park, Queens, City of New York. 

That explains way more than I even realized. Do you even know the science of color, sir? I do. It was my life for over 30 years. I gave a Money Talk at an ANA convention in Chicagoland on what photographic science can teach us about toned coins. 

[Henri Charriere]

2 minutes ago, VKurtB said:

That explains way more than I even realized. Do you even know the science of color, sir? I do. It was my life for over 30 years. 

Is this your quaint way of saying even with your massive infusion of knowledge and experience, you are still unable to see the plain-as-day number eight???!  I mean, I see it, and I've got cataracts.  What's your excuse, phosphorescence?  Who's zoomin' who here?

[VKurtB]

12 minutes ago, Quintus Arrius said:

Is this your quaint way of saying even with your massive infusion of knowledge and experience, you are still unable to see the plain-as-day number eight???!  I mean, I see it, and I've got cataracts.  What's your excuse, phosphorescence?  Who's zoomin' who here?

They do not show on my cheap old phone, but are clear as day on my wife’s newer one and my computer monitor. Those who are literate can determine that from the above. 
 

Color is not uniform. It all depends on the choices of inks and dyes in the printed page, and the choices of color devices in additive color such as screens.

Skip’s photos on this thread are among the worst I have ever seen anywhere in terms of calibrated color. I mean cripes, if you’re going to ask about why color is important, shouldn’t you have the obligation to get your photos to some semblance of correct color? On this, @RWB is spot on. 

Edited September 1, 2020 by VKurtB

[RWB]

RE: "Skip’s photos on this thread are among the worst I have ever seen anywhere in terms of calibrated color."

From old posts on another message board I recall that common fluorescent lighting was his preference for detecting problems on coins. That might be a personal preference and not something useful to others. The photos in this thread have the same distorted color profile as I remember for the old posts. If his methodology worked for him, and produces reliable results, that is good. But I cannot visually or electronically get much useful data from the OP's images. It's like starting with a corrupt database, then applying corrections to pieces of it and hoping it comes out with something usable.

PS: I always calibrate against a Kodak 18% gray card. My computer monitor is calibrated to Adobe Photoshop's same standard.

Edited September 1, 2020 by RWB

[VKurtB]

3 minutes ago, RWB said:

RE: "Skip’s photos on this thread are among the worst I have ever seen anywhere in terms of calibrated color."

From old posts on another message board I recall that common fluorescent lighting was his preference for detecting problems on coins. That might be a personal preference and not something useful to others. The photos in this thread have the same distorted color profile as I remember for the old posts. If his methodology worked for him, and produces reliable results, that is good. But I cannot visually or electronically get much useful data from the OP's images. It's like starting with a corrupt database, then applying corrections to pieces of it and hoping it comes out with something usable.

PS: I always calibrate against a Kodak 18% gray card. My computer monitor is calibrated to Adobe Photoshop's same standard.

As it should be. The nonchalance about color in this field drives me buggy. If I see one more photo of a Lincoln cent rendered as neutral gray with blue fingers holding it because someone used Auto White Balance, I may scream.