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And the greater the magnification, the worse the eyestrain if you spend hours looking at minute details. I collect overdates, so I'm scrutinizing small details and my 8X works great for that. I use this Peak slide loupe because its really easy on my eyes--flipped over works best. For coin shows, I use a smaller 8X jeweler's loupe. Spend the money for good optics--your eyes will thank you for it. 
Posted 07/31/2013 02:43 am
Fortunately for me, and for a surprisingly large enough proportion of the population, my eyes have deteriorated by nearly the same amount.
For normal reading, the prescription for both lenses in my glasses is very nearly the same. Standard 2 dioptres, 500mm focal length, for both lenses, no other problems.
This is where the good fortune comes in. Using these as a standard comparison, I can buy cheap reading glasses for as little as $5.
DO NOT buy cheap glasses, if the prescription for your normal reading glasses varies, with respect of one lens to the other.
When I need to look at my coins in greater detail, I use cheap 4 dioptre lenses, 250mm focal length. Everything at +500mm looks blurry, but at 250mm the coins are in perfect eye range.
The advantage of binocular vision is retained, and leaves BOTH hands to hold the coins. I get 4x magnification at 250mm as well!
For really close up work, I use a 25mm focal length 10x triple element cloth examination glass. It has lenses about 30mm diameter, and has a depth of field of around 10mm. The great depth of field allows me to look at the whole of the coin, without ANY eyestrain, but with one eye only.
I also have a 20x triple element glass, but it has a very narrow depth of field. Not used for coins, but is excellent for the examination of internal flaws in natural gem material, especially emeralds. In this case, you want to look at the flaw only, not the whole gemstone. This glass could be used for examining altered dates and mintmarks.
Then again, there is nothing wrong with using a USB microscope, with pictures for ALL to see! Just takes a lot more setting up, than using hand held magnification.
For a beginner with good eyes, there is nothing wrong with using a 'squint' type loupe, similar to what the old time watchmakers used.
They can be bought from a gem cutting supplies dealer, for not much money. Look in the phone book for 'lapidarists supplies'. I use these for normal gemcutting work, when I am at work on my faceting machine.
You can use only one eye, but at least both of your hands are free.
For normal reading, the prescription for both lenses in my glasses is very nearly the same. Standard 2 dioptres, 500mm focal length, for both lenses, no other problems.
This is where the good fortune comes in. Using these as a standard comparison, I can buy cheap reading glasses for as little as $5.
DO NOT buy cheap glasses, if the prescription for your normal reading glasses varies, with respect of one lens to the other.
When I need to look at my coins in greater detail, I use cheap 4 dioptre lenses, 250mm focal length. Everything at +500mm looks blurry, but at 250mm the coins are in perfect eye range.
The advantage of binocular vision is retained, and leaves BOTH hands to hold the coins. I get 4x magnification at 250mm as well!
For really close up work, I use a 25mm focal length 10x triple element cloth examination glass. It has lenses about 30mm diameter, and has a depth of field of around 10mm. The great depth of field allows me to look at the whole of the coin, without ANY eyestrain, but with one eye only.
I also have a 20x triple element glass, but it has a very narrow depth of field. Not used for coins, but is excellent for the examination of internal flaws in natural gem material, especially emeralds. In this case, you want to look at the flaw only, not the whole gemstone. This glass could be used for examining altered dates and mintmarks.
Then again, there is nothing wrong with using a USB microscope, with pictures for ALL to see! Just takes a lot more setting up, than using hand held magnification.
For a beginner with good eyes, there is nothing wrong with using a 'squint' type loupe, similar to what the old time watchmakers used.
They can be bought from a gem cutting supplies dealer, for not much money. Look in the phone book for 'lapidarists supplies'. I use these for normal gemcutting work, when I am at work on my faceting machine.
You can use only one eye, but at least both of your hands are free.
Edited by sel_69l
07/31/2013 03:07 am
07/31/2013 03:07 am
