6-Piece Mini 30X 21mm Jeweler's Loupe Magnifier Magnifying Glass Set in Silver with Box for Jewelry Review

I ordered these loupes for my education. I was curious about the cheap 30x magnifying glass, since I now use the 10x. They had the same magnification as my 10x loupe. They are mislabeled and I wasted my money. Since then I have tested a 20x loupe and the difference is noticeable. I won't buy this again.

This is NOT a set of "30x Jewelry Loupes" but it is a fairly sturdy and inexpensive loupe (I paid $12.15 for 6) that should stand up to moderately heavy use . To me, to measure "power" a focused image of a 7mm long object fills a 21mm diameter lens, so simple math says that's a 3x magnification. A little over $2 each, they are inexpensive enough that I can put them anywhere in my house that I thought I might need a 3x magnifier and still have some left over to use as holiday stockings . (Just…

Second update: They seem to have a focal length of about 2.5cm. I believe the power of a basic handheld magnifier comes from using a 10" lens and zooming it in to 1x. A lens with a focal length of five inches has a magnification of two or two times. A lens with a base length of two inches has a 5X magnification or a 5X magnification. I have a 5x lens that really focuses to about two inches. In other words, a lens with a focal length of one meter, which equals a thousand millimeters, is called a