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measuring mirrors on dmpl

Posted: Sat Mar 16, 2019 7:23 pm
by oldcollector
hope it okay to ask this here been going through my pl and dmpl coins and how do you measure the depth of the mirrors?
i see on line people say they have 10 inch mirrors etc.
thanks

Re: measuring mirrors on dmpl

Posted: Sat Mar 16, 2019 10:07 pm
by sheatown1
Back in 1981 I bought from Leroy a "Morgan Dollar Proof-Like Guide" . You place the coin upright where indicated and you can see the reflection up to the D.M.PL . He states on the card:
1-2" is Semi proof-like
2-4" is proof-like
over 4" is deep mirror proof-like
I don't know if available now but that's what I used for years-hope that helps

Re: measuring mirrors on dmpl

Posted: Sun Mar 17, 2019 2:19 am
by messydesk
I'm going to move this to the main discussion board so that it gets more eyes.

Standards for PL and DMPL have changed over time. There are DMPL coins in old holders that are almost PL by today's standards. Mirrors are scored by the weakest side of the coin, so a one-sided DMPL doesn't count if the are no mirrors on the other side. For PL 3-4" is what you seem to need now. For DMPL, you need 6-8". Graders don't use a ruler to measure depth when they're grading. They're more likely to use their finger to see how clear the reflection is at various distances.

Re: measuring mirrors on dmpl

Posted: Sun Mar 17, 2019 3:01 am
by CascadeChris
For trained eyes that are experienced in dealing with mirrors, "full" PL fields and "full" DMPL fields are typically pretty easy to recognize at a glance, then you use your thumb to measure how sharp the mirrors are for verification. It's the coins that are "sliders" where the fields are transitioning from either semi-PL to full PL or full PL to DMPL that can be tough to discern which it is. Then, as JB said, it's a sliding scale for the TPGs too as to whether a coin will come back PL or DMPL assuming both sides would typically make it. For instance, the last 5 months or so PCGS has been EXTREMELY critical of PL/DMPL. Coins that would normally go PL aren't and typical DMPLs are coming back PL. It's been crazy.

Oh, and another point to highlight is that every bit of the the fields need to "be there" to get the designation. If, say, both sides are extremely deep and the fields are obvious DMPL, but one small area isnt quite deep enough due to that area having a patch of course polishing lines or an area that wasn't quite polished enough, etc then they typically wont give the designation.. Bottom line is that above almost anything else, PL/DMPL designations are a crapshoot more than almost any other when it comes to guessing what a coin will come back as.

Re: measuring mirrors on dmpl

Posted: Sun Mar 17, 2019 11:20 pm
by oldcollector
THANKS for your help guess ill be going through all of them to try to determine which is which

Re: measuring mirrors on dmpl

Posted: Tue Mar 19, 2019 2:02 am
by blh74
I must be lucky. I sent 7 in the bulk submission with Messydesk. About a year ago. Got 1 no grade and 4 63 DMPL a 62 and a 64.

Re: measuring mirrors on dmpl

Posted: Wed Mar 20, 2019 6:42 am
by VAM-PIRE
On March 16, Messydesk posted that he was moving this topic to the main discussion board. I thought this was it here. If anyone is still stirring at this hour, please chime in with directions to the main disc. board. Thx, VP