A question of lighting when evaluating proofs

Doogy · July 6, 2006 9:06AM

I was wondering what type of lighting should I use when evaluating whether or not to submit my proof halves to PCGS? I would assume I would want to use the same type that they use, as I want to ensure I'm seeing the same flaws (or lack thereof). Any help is greatly appreciated!

Doug

Russ · July 6, 2006 9:09AM

I use a single 100 watt incandescent bulb mounted in a desk lamp with the overhead, (flourescent), lighting off.

Russ, NCNE

mgoodm3 · July 6, 2006 9:11AM

harsh lighting as above.

Doogy · July 6, 2006 9:12AM

<< I use a single 100 watt incandescent bulb mounted in a desk lamp with the overhead, (flourescent), lighting off.

Russ, NCNE >>

Great, thanks Russ!

Doogy · July 6, 2006 9:16AM

Russ,

I recently found these nice (huge!) scans you made of a '64 proof. Does the hazy stuff in the fields represent hairlines on these, or is this some kind of mild oxidation type haze. I noticed a decent percentage of proof '64 Kennedy halves has this, some with more of it than others. Would this detract from a higher grade?

thanks for your help, O' Grand Master of the Kennedy Halves!

Doug

Russ · July 6, 2006 9:21AM

<< Does the hazy stuff in the fields represent hairlines on these, or is this some kind of mild oxidation type haze >>

It is neither haze nor hairlines. In fact, that coin is near perfect - PF69CAM. What you're seeing in the fields is mint frost. Microscopic breaks in the mirroring that were a natural part of the minting process at the time.

Russ, NCNE

Doogy · July 6, 2006 9:38AM

<< 

<< Does the hazy stuff in the fields represent hairlines on these, or is this some kind of mild oxidation type haze >>

It is neither haze nor hairlines. In fact, that coin is near perfect - PF69CAM. What you're seeing in the fields is mint frost. Microscopic breaks in the mirroring that were a natural part of the minting process at the time.

Russ, NCNE >>

cool! thanks for the helpful info!

Doug

CarlWohlforth · July 6, 2006 9:49AM

I use a desk lamp with a halogen bulb. It was sold as a "banker's light". A single point of bright light is helpful when looking for hairlines. A long fluorescent light won't do. You also need to rotate the coin because the hairlines might only be visible from one angle. You also need to look at both sides of the coin.

Russ · July 6, 2006 9:55AM

<< You also need to rotate the coin because the hairlines might only be visible from one angle. >>

A dramatic illustration of that:

Same coin, different lighting and angle.

Russ, NCNE

stev32k · July 6, 2006 10:17AM

Not only are hairlines sometimes only visible from one angle - sometimes the colors on toned proofs can change dramatically depending on the angle. Here are two shots of the same coin with only a small difference in the lighting angle.

Murphy · July 6, 2006 10:29AM

I use a 60-W GE Reveal bulb in my table lamp.

And those marks you asked about are sometimes called "Die-Flow" lines. They do not detract from the grade and in some cases people have used them as an indication of the Die State of certain coins.

You've received some good advice from people but among the best is looking for scratches before you send a coin off for grading. An expert grader will turn the coin 360 degrees looking for even minute scratches.

Good luck.

MikeInFL · July 6, 2006 12:14PM

I have found a small halogen lamp to be the best light source for identifying hairlines.

Incidentally, I thought the lines you mention on the Kennedy reverse were die flow lines....Mike

A question of lighting when evaluating proofs

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