Eyeware For Close Work On Very Small Objects?

I have one of these. It's quite good, with little distortion and no chromatic aberration.

Get an Optivisor. You might luck out with one of the inexpensive look-alikes that use cast acrylic lenses and find one that doesn't have noticeable distortion, and they're certainly worth checking out. But spend a little more and get real optical glass. Your missing headache will thank you. I like the 5 diopter (2.5x) for enough magnification and a decent working distance.

Search ebay for "binocular loupes -lamp -light". They come in all shapes, sizes, and magnifications. I find that 2.5x is about right for me, but if you need more power, 3.5x is common.

Well, $40 is about typical for a binocular 2.5x x 420mm that clip onto existing safety glasses. Here's an example: Add about $20 for the LED illuminator.

I've used the opti-visor type things for a while, and they work for quick tasks that aren't real difficult. But, I do a lot of microsurgery on electronic gear, soldering and inspecting stuff down to 0.4mm lead pitch. The opti-visor just won't do for that kind of stuff. I got a used Olympus stereo zoom microscope from a guy who repairs and sells microscopes that I got hooked up with by asking questions on eBay auctions. He sold me one that was missing the mounting base. I made a simple base, then made a much better one later from a scrapped lathe chuck and an arm made from a MacPherson strut rod. I made a ring light from a bit of PC board and 8 white LEDs. I use this every day, sometimes for hours, and it is just great. (I've even done some actual surgery picking splinters out of my own and family member's fingers.)

At work we have a $500 Chinese stereo zoom microscope with stand and ring light. The fluorescent ring light ate up too much of the valuable working distance, so I made another LED ring light. I was real skeptical of this unit on eBay, but was surprised by the quality. Both the general mechanical stuff as well as the optics work VERY well.

So, if you need to do a lot of this inspection and rework stuff, I strongly recommend a stereo zoom microscope. There are constantly units on eBay to choose from.

Jon

Yes, especially for things like hand-soldered 0.5mm pitch TQFPs and similar.

I've been using this one for several years now for inspection (rarely for actual soldering; the Optivisor is for that): It's 24/40 rather than a zoom but that's sufficient for what I do.

It ain't fancy. The case is handy. The LED illumination works okay with rechargeables (it comes with a "dumb" charger but I use an offline La Crosse charger). Optics are good enough and I can snap a digital picture for documentation by holding a point'n'click camera up to an eyepiece. More room between the post and the stage would be nice. Might put together a boom stand, one of these days.

Per Rich Webb:

But it does not focus, right?

i.e. your vision needs to be already corrected to 20-20 before you use it.

??

Per (PeteCresswell):

I'm thinking about buying these:

Quality is not such a big issue with me because they would only be for occasional use - and not for that long a time each use.

Not really, since by changing the distance to the object you can adjust the total focus (lens + eye), just as well as you can using a single magnifying lens. However, if the focal length of your eyes are significantly different from each other then I'd guess it might be hard to get a good, clear image on both simultaneously.

I have several of the plastic headband ones. One thing to watch out for... Put it on your head and check the clearance between the headband and the hood with the lenses. They're designed to just swing up and out of the way. Problem with some is that there's interference between the headband and the hood that swings up. Takes two hands to move it out of the way. And you can't tell in the package, cause the band deforms when you tighten it on your head.

I also have an optical stereo zoom microscope. Very handy for inspection, but it's very hard to work under. It's just too close. And mine has an accessory lens that extends that distance somewhat. Still hard to get tools under it. And I worry about the smoke from soldering messing up the lens.

Second issue is lighting. Your hands are always in the way. I solved that problem with a fiber-optic light that surrounds the lens.

TRY BEFORE YOU BUY!

I definitely needed that stereo microscope at times when I worked on some things. I don't have access to one now. I was soldering caps I could barely see with the eye. Couple mm long. I used a dual fiberoptic light source which I could move around to get the right view.

Greg

I often used regular cheap reading glasses along with the visor. I had to remove any glasses when using the microscope.

Greg

The advertising verbiage is confusing, it says "Eye Jeweler Watch Repair" and "Required by fishing enthusiasts" and "to ensure a distance of 400-500 meters" I don't believe this item can focus at 16" and 300Ft/ Looking at the pictures, maybe there is enough adjustment on the lens to do that, but I'm a skeptic without enough knowledge to make up my mind. I'm hoping Jeff Lieberman sees this and gives his input. I don't know optics. I do know my optivisor is good at 8", but it's hard to work at 8".

The price is "to good to be true" $29.99.

Mikek

I'd recommend against that type. I have a similar pair. They work like binoculars. You have to adjust the width to exactly the distance between your eyes. Close-up vision requires that they be angled so they converge at the same place they focus.

IFF you can get this done, the slightest movement in your head shifts the relationships, even if it doesn't move on your head...which it will.

In actual use, I found them roughly equivalent to closing my eyes.

I'd start with the visor type with the big single lenses.

Those are binoculars suitable for distance viewing. You can get a clue as to their effectiveness by comparing their size to that of a real pair of 7x35 binoculars.

Cheap and simple optics usually result in some form of aberration. Chromatic (color) distortion, poor depth of field, wrong viewing distance, dim image, etc. You can't really tell the difference between quality and junk until you've made a side by side comparison.

That makes sense if you realize that they're wearable distance binoculars, no close up magnifiers.

Hay, spel my nayme correctlee.

I only know enough about optics to get myself in trouble. Please double check whatever I claim.

This video gives some good advice on the Optivisor: You have the wrong magnification and need to pick the distance at which you plan to work first, which sets the magnification.

Time for you drag yourself down to the drug store reading glasses display. Bring a tape measure and some reading material. What you want to do is pick a specific power of lens and measure the distances where the image remains in focus (depth of field). High power glasses will focus over a short distance and will need to have the reading material fairly close to your eyes. Low power works over a larger range of distances and farther away from your eyes. Make a chart and nail it to the wall. Don't bother trying to find a "typical" chart on the internet as the depth of field varies with your eyes. If you have astigmatism, like me, it can be rather atypical. There are also different definitions of diopters as well as "conventional" and "maximum" magnification.

# stolen from some long forgotten web pile:

Diopter is a measurement of a lens? ability to bend the light of a viewed object and thereby increase its apparent size. Each diopter represents a 25% increase in the size an object is magnified. A four diopter lens (referred to as a 4d lens) would increase the size of an object by 100%. Viewing a 2 inch wide object under a 3 diopter (75% increase) magnifier, would increase the size of the object by 1.5 inches and cause the object to appear to the 3.5 inches wide. The diopter of a lens can be calculated by dividing the number 40 by the focal length (in inches) of a lens. Once the diopter number is known, other parameters such as magnification power and total power can be calculated.

Magnification power is a measure of how much larger an object is after magnification. A magnification power of 1x means the object?s size has been increased by 100%. Our 2 inch object seen through a lens with a magnification power of 1.5x would appear to have added 150% on to its original size. So the 2 inch object will appear through the lens to have increased in size 3 . Its new size would be 5 inches (2 inch original size + 3 inch increase in size). Since the magnification power represents 4 times the diopter number, divide diopter by 3 to calculate it.

# end stolen material:

Caveat Emptor.

The Harbor Freight product is $4. I own it. I use it. It works. And it has four magnifications, not just one.

The claim that glass lenses are inherently superior is not true for simple one- or two-element optical systems. Plastic lenses can be aspheric, at low cost. Whether the lenses in the Harbor Freight product /are/ aspheric, I don't know.

Well, I'm not sure what they are. Apparently it was written in Chinese and translated by a not very skillful translator. About the same as a lot of instruction manuals I have seen with cheap Chinese products.

Bill

I sincerely don't mean this as an offensive statement, just an observation. Sometimes it helps in translating the translation if one thinks in terms of literal, backwards, and upsidedown. Go read the sentences from back to front and see. I used to get a lot of poor translations and the technique worked surprisingly well.

Measure your interpupillary distance (hold a ruler up to your face and look in the mirror; +- 1 mm is good enough). Then go to zenni.com and order some glasses. I'm slightly farsighted, but my lab glasses are regular bifocals: +0.75 diopter for reading and computing, and +2.75 diopters for close work. They cost about $30-$40 a pair for nice coated ones. I usually buy three sets at a time, and it's still less than half of what Lenscrafters wants.

Cheers

Phil Hobbs

The good ones have a "working distance" of 4 to 6 inches, or even more! This is a spec that SHOULD be listed, just check that any particular unit has enough.

I made a ring of PCB material, cut a groove so there is an inner and an outer ring, and soldered 8 while LEDs to it, with series resistors. Works great, hugs real close to the SIDE of the microscope body, so you don't lose any of that precious working distance. Runs off a wall-warp power supply. I've made two of these now for different scopes, I really like them.

Jon