The importance of consistent coin viewing conditions.

[RWB]

An off-topic post about dress colors on another message board reminded me of the subjectivity of human vision. We see colors that we expect to see and not what is really present.

 

Thus, when viewing coins it is important to establish your personal standards of lighting, then stick to them. One suggestion is to carry a small Kodak gray card with you. Put this behind the coin and holder as you examine the coin. It will give your eyes a standard color reference that will help (not completely fix) with assessing the real color of a coin.

 

This can be especially helpful to those who like colorfully toned coins, or who see "green" in nearly every gold coin they handle.

 

Back in the ole dayz of film, you had to select the film's spectral response to match the light source. Otherwise, you ended up with green people when using fluorescent lights and yellow-reddish people when using daylight-balanced film under tungsten lights. Color balancing photos was a major part of any commercial photographer's knowledge base.

 

Now, just hit the white balance button and hope it's OK. (White balancing works best off the same Kodak gray card - 18% reflectance, neutral color.)

[DaveG]

Good Advice!

 

By the way, Roger, do I recall correctly that I recently read that you were the photographer for Kam Awash's 1977 book on Seated dimes?

[wdrob]

Out of these three cards I have assumed the one with the 'X' on it is the 18% card and that is what I have been using to set my white balance.

 

Looks grey to me. Is that the right one to use?

 

[RWB]

Dave G: Yes. I did most of the photography, but not all. My photos are sharp, clear ones featuring the coin not the background...

 

drob: I can't tell. You have to buy the correct gray card. Kodak is the standard, although some use the Macbeth. 18% gray is the international color calibration standard for consumer products - cameras, video, etc. The reverse of the Kodak card is 90% white and of course can be used for white balancing also. (Gray and white are the same color - just a change in luminance -- or lightness in the HSL model.)

[wdrob]

I did buy the correct 18% grey card. Those three cards are on a single clasp. Being color blind I was asking to make sure that the top one was not the 18%. It did not come with instructions. I guess they felt like anyone taking photos and buying white balance cards would not be color blind.

 

Of course I can tell that the middle one is black but I just threw that in the picture as a reference.

 

To me, the top card does not look 100% white in hand or in photo. To me it is slightly shaded grey. So to all the non color blind folks that know what a 18% shaded card should look like. If I received all three on a single neck strap and clasp, would the one with the ''X" on it be the 18% ?

 

 

 

 

[RWB]

Sorry to learn you're color blind. Must be a real irritation to buy clothes.

 

I'd guess the one with the "X" is 18% gray. But without knowing the source of the three cards, it's tough to say "Yes, that absolutely is a standard 18% (or 90%) card."

 

As for white ... many things we see as "white" use fluorescent dyes to make them look white. If you holed your three cards under a UV light, in a dark room, they should all look about the same, even to a color blind person.