I wanted a large boom microscope for electronics. The options were not cheap, at least not in Canada.  $500 for the scope, plus $100 shipping, plus sales tax, plus exchange on the Canadian dollar. The delivered cost of the scope would be around $1000 Canadian. Too much for this hobbyist. So I sadly looked at pictures and tried to convince myself to pony up all that cash. Then, an internet miracle occurred. I found an article about a long forgotten workhorse of a microscope The BAUSCH AND LOMB STEREOZOOM 4.    I was intrigued............

At fifty something I can no longer read the markings on ICs even with reading glasses and my arms aren't long enough for me to hold a book at distance where I can focus on the type. Surface mount soldering isn't in the realm possibility without some serious magnification. I now wear reading glasses even at the computer. If you are laughing right now don't worry your time will come.

StereoZooms were made between 1959 and 2000 under the names Bausch and Lomb and later as Leica and Cambridge Instruments. They were uses in schools, laboratories and attached to some production equipment. All of them carry the trademark StereoZoom name. There are fixed magnification and various zoom models in this family. I have included two brochures in the documents section for you to download and read. The brochures are a huge asset when trying to identify various bits and pieces that are up for sale. The most common model seems to be the StereoZoom 4 with 0.7x to 3x magnification. This is the model I have so I will focus on that.

The microscope's total magnification is calculated by multiplying the magnification of the scope by the magnification of the removable eyepieces.  With 10x eyepieces I get a magnification range of 7x to 30x . The zoom knob is inconveniently located on the top of the scope, which makes constantly zooming in and out a little awkward, but probably not how you will use the microscope anyway. I generally set the zoom once and go to work. The zoom range can be further modified with different eyepieces and Barlow lenses... more on that later.

Like B&L I will divide the microscope into four parts :

1  Head with the optics

2 Eyepieces

3 Focusing mechanisms / base

4 Accessories

Head:

I bought all of my parts on eBay. Some of the heads I  bought were listed as "for parts or not working". This means the seller offers no warranty, it does not necessarily mean the microscope is broken. A careful inspection of the pictures can tell you a lot about the condition of the head. That being said if you need to buy two to make one that can happen. At $35 for a "no warranty" head I decided to take the chance.

You will likely find the best deals on items that are poorly listed. Listings with very general terms won't make it into to your search. So search eBay with a variety of term (and different combinations)  such as - Bausch and Lomb - Leica - Cambridge Instruments - microscope - stereo microscope - stereo zoom - stereozoom. All you are really looking for is the head and E arm. The rest you can build or buy inexpensively.

Listings often read "no objective lenses"  when the eyepieces are not included. Objective lenses are at the bottom of the microscope and they are nearly impossible to find and insanely expensive. Make sure the objective lenses are included !  Eyepieces on the other hand are cheap and plentiful. Bare in mind that sellers often don't know microscope terminology. You  can always ask the seller a question or request additional photos.

The StereoZoom uses mirrors instead of prisms. This makes the head lighter and brighter. De silvering of the mirrors will make the microscope dark or completely useless. A picture showing light passing through the head is very helpful. Mirrors are also nearly impossible to find and insanely expensive.

A stiff zoom knob probably means that it needs re greasing, but the mechanism could...

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