Anyone Use Enlarger Lenses As Loupes?

A coin dealer in Nova Scotia I used to work with loved using his lens (don't know any specifics) and upon trying it once, thought it worked great. Easy to handle and seemed easy on the eyes. I just never really knew where to get one or what really to look for, but may look harder now.

Not the same thing...I know a lot of collectors and dealers who use eyepieces as loupes, and they tend to be quite good quality. But they are a completely different animal than an enlarging lens.

In microscopes, there are two basic optical elements: the objective, and the ocular. The objective is the lens that faces the object, while the ocular faces your eye. Objectives usually set the overall magnification and quality of the image. Oculars (eyepiece)magnify the image created by the objective and match it to the requirements of your eye (field of view, distance between lens and eye, etc). Problem is that the design of the ocular is usually such that it must be used "backward", ie so the end that is supposed to go toward your eye actually goes toward the viewing object. Thus it is being used in a reducing mode, rather than magnifying as it was intended, and the image quality suffers. That said, I have a bunch of eyepieces around and they do make good magnifiers!

It may be your eyepiece is a "true" 10x while your 10x loupe is a "marketing" 10x.

Diatribe follows...Most eyepieces are 10x, and it's quite uncommon to find any that are higher than 15x. This is because the overall image quality starts to suffer beyond this point due to what the microscopists call "empty magnification". If you want to double your magnification with high image quality, you won't get there by doubling your ocular power. You need to double your objective power because doubling the ocular magnification halves the effective aperture. It's the same optical effect as adding a 2x teleconverter.

It's not an enlarging lens but I made this setup using a disassembled (very cheap) pair of 10x50 binoculars and a pvc reduction fitting. The image I get is not super but it works good if you're going through a bunch of coins looking for dates, mint marks or gross errors.

rmpsrpms, thank you. It seems to work well.