I presently use an old Edroy that works well but has too short a working distance. Are there any grades between the $35 B&L and the $350 Zeiss?
Kevin Gallimore
I presently use an old Edroy that works well but has too short a working distance. Are there any grades between the $35 B&L and the $350 Zeiss?
Kevin Gallimore
I like my Optivisor with the glass lens option. The working distance depends on magnification factor, I have the 2-3/4X @ 6" distance. The lens are pretty good, I barley notice any distortion at the very edge.
If you keep the box & receipt they have a lifetime warranty but I have never needed to take them up on it so far.
Also I find very handy is my flip-up eye loupe that clips on my glasses. It has 2 lens that are 3.5X that can double to 7X. The 7X does have a short working distance but is nice to have that available, the 3.5X WD is about 6".
MikeB
BQ340 wrote in news:4fb30fa8$0$7431$a8266bb1 @newsreader.readnews.com:
Enco sells Optivisors, and frequently has them on sale. They can gt down to about half of what a lot of places charge.
I have about 6 pairs scattered around the house & shop, and several more at work.
Doug White
Dittos on the OptiVisors! I too have a bunch scattered where I need them.
For longer working distances with adequate magnification you really need ones with two lenses like what dentists use. They have a positive lens in the front and a negative lens in the back to make a small Galilean telescope. To be compact and have a good field of view, the lenses have to be steeply curved. If each were only a simple lens the image would have lots of spherical and chromatic aberration. A high quality magnifier will have a cemented doublet in the front and perhaps 3 lenses in the back which is why they are so expensive. Even so, the field of view is limited.
I have seen things that look like this on ebay for $50 or less. Obviously these are not great quality but can you even be sure they contain more than one lens? Otherwise the cheapest I have seen from reputable dealers is $189. I am an optical engineer, and I do not understand why someone could not make something like this with plastic lenses for even less than $50. The field of view might only be, say, 30 mm or so, but I think there might be an application for that for machinists.
Do you have to pay that much? I copped a cheap ($4) set for taking splinters out of my finners a few years ago, and they're holding up fine.
Google "head magnifier" for more options/brands/prices.
-- The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man. -- George Bernard Shaw
The Optivisors are much better than the B&L at about 1-1/2X the price. The have excellent glass lenses and a better head band. The head band could be better, but it works just fine. The B&L head band is a POS; the lenses are acrylic and make me feel cross-eyed.
+1 My dentist let me play with his in between patients and I was sold on the concept. I paid about $75 for a fairly cheap clip on model slightly used from Ebay. I don't use it that often partly because I feel like I should take special care with it but sometimes it's just the right tool. More often I use most this type from HF
So how does the $75 dollar ebay model compare to your dentist's? (working distance, field of view, color correction, aberration?)
I didn't have that long to experiment at the dentist and I didn't get my own set until about 2 months later so I can't answer your question very well. I'd say that field of view and focal distance were similar. Mine is about 1.65" at about 16". Optical quality is surely worse and I'm not qualified to state anything definitive but I haven't noticed any detriment for my use. IIRC the dentist said he paid $1500. Even allowing that he doesn't seem the type to shop around I paid at least
10X less. I safety wired mine onto a retired prescription frame which wasn't designed for the extra weight. The bridge would get uncomfortable quickly but I fixed that by wedging a cylinder shaped foam earplug into the bridge.Something I forgot to mention years ago I bought a $10 vet otoscope that looks like this one
I also use a fip-up loupe that clips onto my glasses, but now I'm preparing to order some magnifying glasses from Zenni. My prescription, but focusing much closer than normal reading lenses. I plan on placing the order in the next week or so. I'll report back here.
Also, I had no idea that you could get the telescope-type magnifiers so cheap. I always imagined them as a greater than $1K item. Now I'll have to look for a pair.
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