DIY Loupe




A loupe is a nice tool to have on hand when you want to peer into the world of the tiny. Gemologist use it to inspect gems and rocks that may be valuable. Watchmakers use it to inspect the clockwork of watches. I use it to inspect the back of my hand. Who knew the back of my hand would reveal such an interesting landscape.

One day I was at a Goodwill store. I shop there at least once a month and they always have 35mm film cameras for sale. People cannot get rid of them fast enough as digital cameras have for the most part taken their place. Some of these film cameras were top notch in their time and it was ashame to see them unwanted. For some reason I had the idea to repurpose the lenses in these cameras into a homemade loupe. Some of these cameras have quality achromatic lenses with antireflective coating and produce a flat field of view. A quality loupe can cost thirty dollars and up and Ebay is full of five dollar loupes with questionable quality as varied as gas prices. Goodwill sells the cameras for around three dollars. There is not much to lose and you may even find a camera lens that can rival more expensive loupes.

I find that the best candidate camera to extract the lenses from are the fixed-lens cameras. Zoom cameras tend to have smaller lenses that can be used as loupes. The lenses are usually doublets and are grouped together in a cage. If the camera has a big lens on the back it may not be ideal for our purpose. Also, make sure the lenses have antireflective coating so you can be assured that the manufacturer put in the extra step to make the lens as best as possible. Lenses with antireflective coatings will look purple or green and sometimes amber. Ignore cameras that don't have it as the lenses are probably not even glass but plastic.

35mm fixed-lenszoom lens

In my recent Goodwill hunting I bought three cameras by Nikon, Pentax and Minolta for around nine dollars. The Minolta is a fixed-lens camera while the other two are zooms. After removing a ton of tiny screws I got the lens barrels out. It's too bad I don't know what to do with all the plastic gears that fell out. I'm sure I'll find a use for them.


It is important that I warn you that the cameras contain circuits that drive the flash and could potentially still hold a dangerous charge. You can see the 330V capacitors and part of the driving circuit that makes one shake at the knees. As a matter of fact before dismantling the Minolta I was willy-nilly shooting away with no film in the camera. I just enjoy shooting the flash. I cracked open the camera and spotted the capacitor. I knew it had a charge since I was just shooting it. I took a scissor and carelessly cut all the wires and I was rewarded with a loud pop and a spark. I did not get shocked but my scissor showed partial melting of the cutting edge. So, be warned and properly discharge the capacitors to be sure.


Here's my collection of lenses thus far. The biggest loupe I have so far has a 14mm objective and has a focal distance of one inch. Eye relief is also about an inch. Field of view is about 22mm. I have not compared it to a real loupe but I would say the magnification is roughly 10X. You can even combine these compound lenses for extra magnification.



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