Union Auto Illumination inverted microscope

Received from Mr Graham Pratt

Dear Mr Saunders-Davies,

I have been fortunate to acquire a Union Auto Illumination Microscope, Mic 969. It seems a most desirable instrument, with superb build quality. However, I do not have any instruction manual or details of this instrument. I have contacted the manufacturers, who still make microscopes in Japan; apparently its manufacture was discontinued some thirty years ago and unfortunately they cannot supply me with any details. I wonder if your good self or any of your colleagues have any experience with this instrument? I have included four photographs showing various viewpoints of the microscope.

Union Auto 1Union Auto 2

Union Auto 4Union Auto 3

There are three eyepieces, a matched pair marked WFH10× with detachable soft plastic extensions, for spectacle wearers. The third eyepiece is marked Ke10× and has a helical focusing thread. [Ed: A measuring graticule would be placed inside the eyepiece, and the helical mount used to focus on it.]

There are six objectives with standard RMS thread, all coated lenses and all carrying the designation T.L. 170. Starting with the lowest power, M5×, F10×, MF20×, MF40×, BF40×, and lastly, Oil M100×. All the optics are original and carry the microscope logo.

The microscope itself has two light sources. One at the top includes a condenser with comprehensive adjustments, and filter slots. The other is placed beneath the objective turret and illuminates the subject through the microscope objectives; this assembly has an aperture iris diaphragm, a field iris diaphragm, filter and polariser mounts. At the other end of this structure is an oblique optical mirror; is this for adjusting the light source?

Finally the microscope uses two bulbs, and I was fortunate to have five spares. They are bayonet type 6 volt 15 watt bulbs, about the size of an old-fashioned torch bulb, carrying the designation EL-11. Well thank you Tony for your kind assistance. Please excuse the terminology etc. as I am very new to microscopy.

Kindest regards

Yours sincerely

Graham Pratt, Wigston, Leicester

[Ed: While this was e-mailed to me, it was so interesting, and posed so many questions that I hope many readers will be able to answer, that I felt it deserved a separate section. Congratulations Mr Pratt, you have clearly acquired a very fine instrument!]

↑ Top of page


Following the publication of the article on the website, the following e-mail was received:

2nd March 2003

Hello Tony

With reference to the Union Microscope item on the Internet, could I refer you to items of mine in the Manchester Microscopical Society’s newsletters 51 and 52, that is the January and May 2002 editions, in which I wrote papers referring to my Union Inverted Microscope. Edition 51 gave details and 52 showed the microscope as used in DEP research. It is a very good machine, and I have had mine for a considerable number of years. I find it equal to Wild and Nikon inverted microscopes that I used in medical research at a University Department in which I worked. I could not find any address for Mr Pratt to contact him direct.

Best wishes

Lawrence M. Bowler

↑ Top of page