BINOCULAR MAGNIFIERS COMPARED

THE RULES

With any simple lens, the stronger the magnification, the closer the magnifier has to be to the object (the 'working distance'). A general purpose folding magnifier of 4X magnification would normally give a working distance of 2.5 inches (60mm), at 10X this becomes 25mm, at 30X a fairly useless 8mm, and at 50X a completely useless 5mm (for a handheld magnifier) - though that doesn't apply to simple microscopes that are pre-set to focus on a flat surface, and with a built-in light.

Now imagine wearing a binocular magnifier and viewing an object from an inch or two away - you will not be able to use both eyes, you will be too close, you will loose binocular vision, there will be no point in using a binocular magnifier.

Therefore, for the simple-lens magnifiers you have a choice: keep the magnification under 2X to get a decent working distance, or go up to about 3X but with a very short working distance
...however...
it is possible to get magnifiers made out of "little telescopes" (the type that surgeons use) which have a long working distance for the magnification - scroll down or click here to see them.

To find out more about how magnifiers work see How to Choose a Magnifier

Simple type

There are some that clip to spectacles. The very simplest is a double lens that simply adds 2X magnification to your spectacles, it is only £3.50 but please be aware that you are only buying £3.50-worth of lens quality. For 'flexibility' try one that comes with a selection of lenses (each is a different magnification) either with a built-in light at £12.50, or without (from £9.50 to £17.50). For the best lens there is the Zeiss version, it is better than the others but, in my opinion, the difference isn't dramatic, I would rather go for the basic surgeon's type which is the same price, £69.00.

At the bottom of the same page are similar items, but built into headbands. The 'cheapy' version has thick glass lenses, a 'visor' made of a thick black plastic, and the 'band' is a piece of elastic, all OK for the price, just £7.50, the quality is not amazing, the style is very 1960s. At the other extreme is the Zeiss - it uses the same Zeiss lens as the Zeiss-clip-to-spectacles, but in a headband. Finally, one that has a selection of lenses and you can use two at a time which gives a large range of magnifications and it has an adjustable light. The low-power lenses really are quite OK, but do remember that what I say above about magnification and working distance applies; once you start combining the lenses to get high magnifications (you can use two lenses at a time) you end up too close to the object for stereo vision to work.

Which one?

If you don't wear spectacles you will need the headband version, but spectacle-wearers can also use them, they fold down over the spectacles. Although I think the two 'cheapies' (£3.50 and £7.50) are unspectacular in quality, they might be OK for the very occasional repair job.

Those that come with a selection of lenses are a good idea if you tend to do different jobs that require different magnifications, e.g. changing a fuse in a dark cupboard one day (popular with electricians) and gluing an antique vase the next day and reading a book in bed the next day.

My colleague likes the headband magnifiers, he says they are more comfortable than those that clip to spectacles, he uses them for repairing clocks, and I know two people who use them when working on a lathe, I think the 'closed in' feeling makes them feel 'secure'.

My partially-sighted 'testers' tried the clip-to-spectacles lenses with light - one said it was 'OK', one said it was 'too fiddly', one said it was very good indeed because of the light, and because the light always pointed at the page, unlike a bedside light when you turn away from it. It is a little fiddly clipping the lenses in and out, and it does have to be clipped on straight (if you clip it to spectacles lop-sided you get distorted vision and end up feeling dizzy).

The clip-to-spectacles types are on page 10 of our Winter 2010 - Spring 2011catalogue, the headband types are on page 13.


Surgeon's Type (Page 12 in our Winter 2010 - Spring 2011catalogue)

As explained at the top of this page, the more powerful a 'simple type' lens, the closer it has to be held to the object (working distance). These magnifiers are made of miniature 'telescopes' rather than 'simple' lenses, and so you can achieve higher magnification and longer working distance.

The basic, £79.00, version has a working distance of 12 inches (30cm) and a magnification of 2X, which enables you to work quite comfortably at arms-length when sitting at a bench. I call these 'surgeon's type' and not 'as used by surgeons' because the actual type used by surgeons cost between £750.00 and £1500.00. so don't despair that the optics aren't 100% perfect, this is still an excellent magnifier, I used one myself before I got the professional models (listed below).

The 'professional' models come in two magnifications (3X at £149.00 or 4.5X at £225.00) and for each there is a choice of two working distances, 34cm or 42cm. Each is fixed to a spectacle frame which is lightweight and comfortable (even if worn over the top of existing spectacles). I tried quite a few magnifiers of this type before deciding which to sell, and I find the quality of these quite spectacular and the prices are amazingly good, you will be hard-pressed to find 'engineers' magnifiers like these for under £350.00.

Which one?

- WORKING DISTANCE
Choose 12 inch (30cm) or 34cm working distance for jewellery, clock and watch repairing, model-making and other close-up jobs. Choose 42cm for arms-length work such as dentistry, standing at a lathe or working on machines "in-situ."

- MAGNIFICATION / APPLICATIONS
For working with very small items, such as watch making, painting miniatures, renovating paintings, gluing porcelain - any job where you really do need to see every spec of dust, go for the 4.5X magnification(£225.00). For all other jobs, including close lathe work, clock repairing, model making and soldering, the 3X (£149.00) will be ample, there really is no need for anything stronger. If these prices frighten you and all you want is a reasonable magnifier that gives you a long working distance, then go for the 'basic' model at £79.00.

Incidentally, I use a 4.5X at my evening class where I am learning watch making. It gives me stereo vision at comfortable working distance, so much easier than using an eyeglass of the same magnification (which would give mono vision and just 3 inches working distance). I also find it perfect for when the tutor needs to show me something. Instead of trying to get so close that our noses are touching, I can stand back and see everything he's doing perfectly. This also give me an idea. You could view finely-made items in museum showcases, since there would be no other way of getting close enough to use a magnifier.

- SURGEONS AND DENTISTS
The reason surgeons spend over £1000.00 is that they go to their optician who checks their prescription and takes lots of measurements, then the magnifier is custom-made. Ours are not custom-made and so you will have to spend the first 20 minutes adjusting it to line up with your eyes, and collimating it so that each half is pointing in exactly the same direction. Of course, once you have done this you won't have to need to adjust it again - but if you are a surgeon, your department should have the budget to buy one that is made for your eyes and doesn't need adjusting at all (imagine being about to perform an emergency operation and finding someone has been playing with your magnifier and you have to stop for several minutes to adjust it!)
...however...
for a GP Practice that carries out small-ops or a dental practice, where there is no way the budget will stretch to £1000.00, go for one of ours, I absolutely recommend them!