Seems a lot of collectors are using very strong magnification to view/grade coins. My problem with this is if one uses strong enough magnification, even an MS70 will look like the surface of the moon. I’ve asked this question before, but no one seems to know if there’s a standard in the industry. The standard for grading diamonds is 10x magnification, so why isn’t there a standard with coins? I look at the coin first with the naked eye, to judge “eye appeal”, then I scan the coin with a 5x, and rarely use a 10x if something warrants it. So, what’s your opinion?
There was a thread a few years ago about this: http://www.cointalk.com/t12690/ I use a number of magnifications. My loupes have 1.5; 4X; 6X and then I can combine the two lenses on one of the loupes to get up to 10X. For detail eg. rpm's, I use an eyepiece from a video camera which I would guess would be 20X.
I been told that 5x is the standard, but I bought a 10x loupe so I can just have extra magnification on any errors I might find. I do have both the 5 and 10.
If all coins were the same size it would make sense to use a certain magnification for grading, but the same size nick on a morgan makes a less deduction than if the same size nick was on a 3 cent silver. With experience one can "adjust" the "moon surface" in relation to the coin size in their head. I think most graders use a 3x-7x magnifier if they are truly grading rather than authenticating or determining a variety. For general looking at a coin, I prefer 10X as it is low enough to get an over all appreciation of the condition of the coin, and yet strong enough to see indications of the type of varieties I am interested. Jim
I carry a 5x glass for shows and most everything else. My wife got me a stereo scope for Vaming when I get the coin home. She got tired of hearing me mumbling while trying to Vam morgans. Steve
You usually don't need any magnification to grade. There are many exceptions like looking for hairlines or grading MS-70's. Sometinmes it's difficult to tell what's going on with the surfaces and you need some magnification to tell (nrormally 5 - 7x). Sometimes there are characteristics that are too small or too fine to discern so you need magnification. On very rare occassion you'll even find that 5 power isn't enough and you'll need more. Generally speaking high power is used only for attribution or authentication. It is imperative for new varieties and unknown issues.
i got a 5x's and i find it perfect. i actually went and got the last one they had, just in case mine breaks!
When I was searching Mint bags for high-grade business strikes, I would use a 10x loupe to weed out the obvious ones, first. Then, I would use the stereomicroscope to weed out any fair-sized marks in the devices. Finally, I used the microscope to eliminate any with smaller marks in the prime focal areas of the devices. This worked very well for me. About 25% of my submissions would come back MS68 and the rest would usually be MS67. Chris
NGC defines a Mint State or Proof 70 coin as having no post-production imperfections at 5x magnification. http://www.ngccoin.com/coingrading/grading2.aspx It is my understanding that both PCGS and NGC use 5x or less for grading.
Ruben watch about 2:13 into this PCGS video with the President of PCGS. They do first eyeball the coin, and then the "glass" comes out. Remind me not to send coins in during flu/cough season, as they are very close to the naked coin http://www.youtube.com/watch?v=hAQv6qmGcis Jim
I generally look at coins without magnification unless or until I am interested enough to look closer and then I use a 5x B&L. At times I will also use a 10x Zeiss, but this is not for most coins.