June 3, 2021

Olympus Stero Microscopes

The Olympus SZX series are some of the best stereo microscopes that money can buy. However Olympus support for these is terrible. A friend who has an SZX-12 less than 10 years old finds that Olympus no longer supplies repair parts and the microscope relies on an almost unobtainable rubber belt as part of the zoom system.

Two people I know have SZ series scopes and swear by them. I now have the SZH10 (as well as an SZH) and they are fantastic scopes.

Interestingly, the SZX-12 microscope uses a different series of objectives, the "PF" parfocal objectives, available in 0.5x, 1.0x, 1.2x, and 1.6x. The SZX-9 uses the same objectives as the SZH (as described below).

The PF objectives stay in focus as you zoom the power, whereas objectives not so designated do not. As near as anyone I know knows, the PF and non-PF objectives can be freely exchanged and used on any of the SZX or SZH series microscopes.

The SZX-12 is very well regarded, with a 12.86:1 zoom range. 800 lines per millimeter resolution is claimed.

Joe, who has the SZX-12 uses it with 10x eyepieces and the 1.6x objective. This gives him a range of magnification from 16 to 144 (my math says it should go to 192x). He sometimes wishes he had a 2x objective, but overall likes that setup very well. He has tried higher power eyepieces, but feels that the crucial thing is to get the magnification you need by using an objective that gives it to you. Higher magnification eyepieces he feels tend to give "useless magnification".

Joe also has a turret that would allow him to have two objectives mounted and handily switch between them. He does not use it because it interferes with his fiber optic illuminator. Whenever he would switch objectives, he would have to rearrange the fibers and finally he just gave up on it.

The SZX-9 offers a 9.05:1 zoom range (0.63 to 5.7x). New prices are $7000 to $8000.

The SZX-16 is the current high end model. It resolves 900 line pairs per millimeter. The zoom range is 16.4 to 1. It sells for something like $12,000.

The SZX-10 is the current "less expensive" model. The marketing literature says it is "designed for routine research". It resolves 600 line pairs per millimeter.

The SZX-7 is the current "budget" model.

There is also an older but perfectly fine SZH series which seem to have optics of the same quality as the SZX series, but some different mechanical features. In particular, the eyepieces cannot be tilted up and down to different angles. My friend Jerry got a good deal ($4500) on a SZH-10.

I was very fortunate to pick up an SZH-10 at an auction for $800. It came with an 0.5x objective, which gives a huge working distance, but is otherwise undesirable. I picked up a 2x objective along the way, but it just sits in the drawer. I find I much prefer to use the 1.0x

The SZX and SZH series use interchangeable screw on objectives, (but see my note above about the SZX-12 using a different "PF" objective) which are available as follows:

Note that the 1.0x (the most common) was revised and a apochromatic version released. It is bound to be better than the original, but I would expect both to be superb, I would like to know more about this.

As noted above, the SZX-12 (and perhaps the 16) use a different "PF" objective series.

Eyepieces are available as follows:

The trailing value above is the FN (field number), which is the size of the field stop in the eyepiece in millimeters, which is, generally speaking, the size of the viewed field in millimeters. So with a 1x objective, an eyepiece with a FN of 16 will show 16mm of the subject.

Olympus supplies eyepieces in both GWH and GSWH form, and I am unsure of what the "S" means, but rumor is that it indicates "super wide".
The "H" indicates high eyepoint (good for eyeglass wearers).
The "W" indicates wide field.

The GWH10X-D eyepieces on my SZH-10 have an external diameter of 30.0 mm. I read somewhere that the G-series eyepieces have an external diameter of 31.5 mm, but there is no arguing with my calipers (I measure 29.89 mm).
Some more recent Olympus stereo microscopes (such as the SZ-4045) use eyepieces with an external diameter of 32.7 mm. Other microscope makers (such as Nikon) use a 30.0 mm tube diameter, and this would be a sensible standard, if there was such a thing.
There are non-G series Olympus eyepieces (WH15x/14 for example) that look like they have a smaller tube diameter (perhaps the old 23.2 mm standard). I have seen Olympus SZH scopes for sale with both GWH10x and GSWH10x eyepieces, so it would seem that both would work. I have also seen SZ-4045 scopes listed with GSWH10x eyepieces, perhaps these have shims or rings to center the 31.5 mm eyepiece in the 32.7 mm hole ?

The SZ6045 is a very nice microscope, but not in the same class as the SZX and SZH series. Zoom is 1 to 6.3x. I have seen used copies for $1000 or $1200. Refurbished copies with a "pedigree" for $2200.

The following Olympus brochures have a lot of interesting and useful information:

And here is a great article about how a fellow overhauled an olympus eyepiece:

And here is some information on Olympus photo-eyepieces (relay lenses):

Feedback? Questions? Drop me a line!

Tom's Mineralogy Info / tom@mmto.org