Donegan DA-4 OptiVISOR Headband Magnifier, 2X Magnification Glass Lens Plate, 10" Focal Length

This is actually a discussion about three of the Donegan visors: the DA-2. DA-3, and DA-4. Who knows how Amazon groups or separates reviews now. Hopefully this will be accessible and helpful to people seeking all three.They're good quality, as expected, with glass lens plates in the DA series. Note that if you are nearsighted, your eyesight as well as the correction already present in your glasses affect the working specifications of the visor, even more so if you wear bifocals or progressives. This means that the focal length advertised for the Donegan visors will not be your working distance. I cannot speak to correction for farsightedness.Since I'm involved in many interests and wasn't sure how I wanted to trade off magnification and working distance, I bought DA-2, DA-3, and DA-4. I find that despite the many recommendations to stay with the lower powers, which I well understood, I often need the magnification of the DA-4. You may be different. It depends on you and the type of work. I recently had to replace some surface-mount capacitors. They weren't absolutely miniscule, about 3mm diameter, but I needed the DA-4 to see the solder pads clearly enough.But here's the gist. I was surprised by the actual working distances I achieved with all three visors. My uncorrected vision is awful, something like 20/325 and 20/375, maybe a little better as I've aged. My clear vision extends about 9 inches from my corneas, then I'm done. I wear progressives and I use every bit of them, the very tops of the lenses for driving, the very bottoms for any close work.Here's what I get, the usable distance from the work to the visor lens plate. These measurements are close, but not necessarily perfect.* DA-2:Advertised focal length, 20 inchesWith my glasses, distance, 14 inchesWith my glasses, near, 7 inchesNo glasses, 5.5 inches* DA-3:Advertised focal length, 14 inchesGlasses, distance, 11 inchesGlasses, near, 6 inchesNo glasses, 4.5 inches* DA-4:Advertised focal length, 10 inchesGlasses, distance, 10 inchesGlasses, near, 5 inchesNo glasses, 4 inchesTo summarize, all but one of the practical working distances are far shorter for me than the advertised focal lengths, eyesight corrected or not. Even the DA-2, which is probably the most-recommended visor, is a bit short for many activities. The distances decrease with more powerful visors, as expected, but are not always linear. The DA-2 improves my working distance slightly when using the near-vision portion of my lenses versus uncorrected; the others decrease it. All decrease my uncorrected-vision working distance, workpiece to eyeballs.I have an outstanding optometrist who works at one of the local laser surgery clinics. He is so far ahead of the usual ones. We've had long discussions about lens power, and one thing he's told me is that there is no obvious set point of "correct correction" for nearsighted eyes. He says that most people, in the exam, will keep wanting more and more correction, beyond what they actually need. He first reduced my correction and improved the balance of my vision. He makes it a practice to not let people get into stronger lenses than they should ideally have. I bring this up because I'm puzzled as to why my 20/20 corrected distance vision doesn't agree with the Donegan focal lengths except for the DA-4. The weaker the Donegan power, the more the divergence for me. Makes me wonder whether there's a connection to this slightly-weaker distance correction I have. Seems to make sense, but I'm not well-informed enough to know...I'll ask at the next exam.The depth of field is so shallow with these visors that you won't find it useful to "just move back a little" to gain more working distance. To my eyes, from the point of best focus (which is really quite good), there is a truly sharp range of about a quarter inch either way. A depth of +- 1/2 inch gets pretty blurry. Go an inch either way and it's not usable. If you labor under the notion that you'll have vision from "20 inches onward" with a DA-2, that's not true. You'll see from "19 to 21 inches."Lastly, I immediately feel cross-eyed when wearing the visors. I haven't measured, but I think the optical centers are narrower than my own and it strains my eye muscles. I can't wear them for long at a time.Don't misunderstand...I like the visors and do use them. I just don't have as much room as expected.

Good quality

Not a long review but a short review. This is the one you want! Just need to figure out what magnification and distance you need. The headband is the most comfortable.

This headband magnifier is incredibly convenient with its adjustable fit and hands-free operation. While there are many similar options, this classic is trusted by jewelers, watchmakers, and artisans for a reason. Highly recommended for precision work!

These are nice, but you should know that they do not focus at all distances. Vary from the set distance, and the object will go out of focus. I've ended up with two of these so I don't need to swap lenses constantly. My choices:2.0x that has a focal length around 10" That may be closer than you think.1.75x that has a comfortable focal length but not as much magnification.There are others, but you'll either have to bring the viewed object extremely close.Or more distant versions have limited magnification.I've also had problems with the plastic versions of their lenses, so best to stick with glass.There's also a 3rd party light that can help. Even if mag factor is low, it can work like a headlamp.

When I was first looking to order these, I was at a loss as to which magnification strength I should choose. I was leaning toward a higher dioptric strength (like 2.75X or 3.5X), but I was concerned about the listed "focal length" which was very short.I eventually ordered a 2X magnification strength because the 10" focal length is most appropriate for the detailed sculpting work I do (although I'm finding them wonderful for other projects, too).The focal length is very important. If you're using these for regular work, you probably already have an idea of how far from your eyes your project generally is -- your work distance comfort level -- and you should factor that distance into your decision on which magnification level you choose. In my instance, I can't always lift the piece I'm sculpting closer to my face (if it's heavy or mounted on a turntable), nor do I want to shove my face down uncomfortably close to my work. I took the time to determine and measure exactly how close I normally prefer to be when sculpting. That distance, for me, turned out to be 10-12+ inches away. I didn't want to choose a magnification less than 2X, though, so I chose it since the focal length was 10."As an example of how important the focal length is, I wanted to point out that if I shorten or lengthen my distance from my project by more than an inch or so from the prescribed 10", the vision distorts.For additional magnification, they offer an attachable 2.5X loupe magnifier. I decided against that, though, and ordered a second OptiVISOR in the 3.5X for those rare times that I need extra magnification.I'm glad these don't come with an integrated light, because then they'd be much heavier to wear because of the required battery pack. You can add a simple LED light attachment made specifically for them (click here -- Quasar Led Lighting System for Optivisors) if you find it necessary.The OptiVISOR is fairly comfortable to wear. There's a turning button on the very back of the band that adjusts the sizing to fit. The magnification lenses will easily push up (and stay up) out of the way when you don't need them.