Guide to Stereo Binocular Microscopes

For the most intricate repairs of jewellery, miniature paintings; for inspection of PCBs, prints, photographs, stamps, coins, medals; for identification of gemstones, plants and insects.

** See all microscopes ** Hobby and Pocket microscopes ** 
Professional microscopes (including a specialist gemological microscope)
Secondhand microscopes and microscope accessories

This article is in the process of being re-written and may look somewhat untidy until complete. This is because we have a new range of microscopes, available from 15 September.

Contents

Magnifications, Depth of Field & Working Distance
Microscope magnifications
Magnification, Dimensions, Weight, Comments
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Magnifications, Depth of Field & Working Distance

	8X	10X	20X	30X	40X
Product ref. Price includes VAT	Field of view (20p. coin)	Depth of field. Working dist.	Field of view (20p. coin)	Depth of field. Working dist.	Field of view (20p. coin)	Depth of field. Working dist.	Field of view (20p. coin)	Depth of field. Working dist.	Field of view (20p. coin)	Depth of field. Working dist.
micr-stx-20X					1/5	1mm 3”  175mm
micr-8X £95.00	All + a bit more	10mm 8½   229mm
micr-10X-30X			All (Just!)	3mm 4”  100mm			“TWE” maybe 10th	A bit less than 1mm
micr-10X			½	5mm 11”  289mm
micr-gem							“TWENT” maybe 8th	2½”  60mm	“TW”	a fraction of 1mm

FIELD OF VIEW: how much of a 20p coin you can see without having to move it. The letters refer to the word TWENTY on the coin.

DEPTH OF FIELD: how much stays in focus without having to re-focus:

• the 8X stays in focus as you move the item up to 10mm closer / further way, so you can hold an item in your fingers, move it about, and keep it in focus.  
• at 10X (depth of field 5mm) you can manoeuvre an item in your fingers and keep it in focus, providing you have a steady hand.
• at 20X the item has to be kept flat, good for inspection, OK for untangling a hairspring, too powerful for general work on watch movements.
• at 30X or more the item has to be flat to stay in focus, so for gemstones you must refocus to see the surface of a stone or to see an inclusion.  

WORKING DISTANCE: the maximum distance from the objective lens to the table. Also think about the general format of the microscope. Would a "swan-neck" arm (micr-8X) give you enough space to work? Or maybe the long-arm version (micr-10X) is better for large or 'lumpy' objects.  Or if you are working with small flat objects, then any of the other models would be fine.

Microscope magnifications

Our stereo microscopes have WF (wide field) eyepieces, low-power objective lenses, and an optical system especially designed to give long working distances. This makes the microscopes suitable for inspection and repairs (watches, antiques, jewellery etc), "Standard' biological microscopes are different, they give working distances (for the magnifications listed below) of between 35mm and 0.5mm. 

Magnification, Dimensions, Weight, Comments

Product ref. Price includes VAT	Size, mm H - W D	Weight, g Item weight not posting weight	Magnification	Comments
micr-stx-20X	260 - 110 137	720	20X	As a ‘miniature’ microscope, this is good to use in place of a 20X jewellers loupe. Although the optical quality is not as good as our other microscopes, it’s better than any 20X loupe, it’s small enough to carry around in a bag and the light is battery-operated. I would rate the quality, being a) good and b) stereo, as being better than the £89.00 Zeiss lens...though, of course, it won't actually fit into a pocket.
micr-8X	420 - 150 160	4,200	8X	Good for general inspection. The best for repair jobs on the smallest of items, but I mean really small, e.g. miniature paintings, PCBs, very tiny jewellery repairs, and fine work on watch movements, e.g. untangling a hairspring, oiling a jewel (it’s too powerful for general work). It has the same superb optics as the other microscopes, below, but the price is kept down by having a simple swan-neck instead of a rack-and-pinion mechanism, and by not having its own light (use a table light).
micr-10X-30X	300 - 120  180	2,950	10X 30X	10X magnification is the standard magnification for stamps and coins, postcards and paintings, paper and printing, fabrics and any other sheet material. 10X is also the absolute maximum you can actually ‘work under, providing the items are relatively flat, e.g. for untangling a very small hairspring or oiling a really tiny jewel in a watch movement. 30X is good for very fine inspection work, e.g. to check the condition of the edges of a jewel in a watch movement. The light is mains-powered.
micr-10X	465 - 130 260	7,350	10X	Everything I say about 'working under' a 10X, above, applies to this microscope too. This one has the advantage of of a tall stem to keep the lenses high (allows you to work with large objects), and a long arm you can position it over awkward objects (e.g. PCBs or paintings). It's more comfortable for working on movements, it positions easily over a lathe. The light is mains-powered.
micr-gem	310 - 150 200	3,750	20X 30X	Best optical quality and sophisticated lighting for gemstones, see item description.
All of these microscopes are binocular (two eyepieces, you use both eyes) and binocular (two objective lenses for stereo vision).  Stereo vision is comfortable, seeing in 3D means you can spot detail more easily, your eyes don't tire, and it's essential if you need to 'work on' items.

Photographs

THE FOLLOWING PHOTOGRAPHS give a very approximate idea of what you will see (find a 20p coin for reference).  I took them by placing the camera to the eyepiece, really not the best way to take a photograph through a microscope! In reality, you will see a far greater area than shown in these photographs (see 'Field of View' above); in reality the image will be spectacularly stereo, something you cannot appreciate by looking at a picture on a monitor.

20X

micr-8X

micr-10X

micr-gem  Left: at 20X. Right: at 40X

Related Articles

• How to choose a magnifier (plus everything you would ever want to know about magnifying lenses)
• How to choose a jewellers' loupe (including examples of what you will see through loupes)
• How choose a binocular headband magnifier (from simple hobby model to a professional surgeon's / dentists models)
• How to choose a magnifier for the partially sighted (specialist low vision aids including lenses and video magnifiers)
• How to choose a video magnifier (from small pocket-size electronic readers to a large table model)
• How to choose a UV loupe (ultra violet light)
• Calculator (Excel format) - enter the magnification, it tells you the working distance, or enter the working distance, it tells you the magnification.
• Professional USB microscope attachment (it replaces the eyepiece of your microscope)