Page 1 of 1

Manufacturer of this petrographic scope?

Posted: Tue Sep 17, 2019 4:59 pm
by geo_man
Hi all, I just purchased this petrographic scope on eBay. Seems to have a quality feel although it is certainly a basic model. It resembles the Spencers of the 1940's I've seen online. There is no trademark or model # on the scope. Anyone know the likely origin? Unbranded Spencer? Generic knock-off? Thanks in advance!


IMG_1918.jpg
IMG_1918.jpg (168.57 KiB) Viewed 3717 times
IMG_1919.jpg
IMG_1919.jpg (156.31 KiB) Viewed 3717 times
IMG_1920.jpg
IMG_1920.jpg (254.01 KiB) Viewed 3717 times

Re: Manufacturer of this petrographic scope?

Posted: Tue Sep 17, 2019 5:18 pm
by MicroBob
This looks very well made. The big manufacturers wouldn't have shipped it without their name on it. So it has to be a competent company from a smaller, less prominent manufacturer. Here in Germany there were loads of them, but to box doesn't look as if it came from Germany. It might have been made in Japan or China.

Re: Manufacturer of this petrographic scope?

Posted: Tue Sep 17, 2019 5:29 pm
by geo_man
Thanks a lot MicroBob. Yes, its quite nice and looks and feels almost new. Seems strange to me to lack a brand, but I guess it's not uncommon. Cheers!

Re: Manufacturer of this petrographic scope?

Posted: Tue Nov 26, 2019 4:52 am
by dawsonmic
Hi,
I am almost certain that you have a Unitron petrographic. It is identical in every respect to the catalog illustrations I have from the late 1960's, but it is curious that it is lacking the Unitron logo on the tube. One oddity on this particular model instrument is the means of focusing the condenser - it is on a dovetail without any rack & pinion - you have to carefully slide it and then lock it in place with the thumb screw. However, once adjusted you shouldn't have to fiddle with it often. Unitron was made in Japan, and here in the USA the main sales office was in Needham MA. They also used to sell astronomical telescopes and at some point the name Unitron was changed to Polarex, but I am not sure if the microscope line temporarily dropped the 'Unitron' name. I had seriously considered purchasing this very instrument back in 1969 - it was about $285 at the time. Opted instead for a venerable rebuilt Spencer 37A research petrographic at about twice the price, but when it was shipped from Chicago turned out to be an entry-level model. So returned it and ended up without having anything for a while. . . The condition of your instrument is really quite spectacular!
Cheers!
Dave P.

Re: Manufacturer of this petrographic scope?

Posted: Tue Nov 26, 2019 4:59 am
by Scarodactyl
Unitron used to mostly resell Kyowa stuff, which would track with it being a quality-but-obscure Japanese-made scope. I've tried a couple of Kyowa products and been pretty happy with them.

Re: Manufacturer of this petrographic scope?

Posted: Tue Nov 26, 2019 5:09 am
by dawsonmic
Interesting that Kyowa used to manufacture the Unitron microscopes - never knew that! In the meantime, I did look up the literature and the Unitron model was 'MPS'. And I was incorrect about it being absolutely identical - I note three differences comparing it to the literature. The biggest difference is that the MPS used a slider to move the Bertrand lens into position, whereas this instrument has the knob that appears to swing it in and out of the light path. That is defintely an improvement over the slider which exposes the rather tiny lens to dust when in the 'out' position! The clutch mechanism is also slightly different. The only other difference I could see was in the design of the back of the foot, being less rounded than that of the Unitron. I am guessing this is a somewhat later instrument than the MPS. Would be curious as to when it was manufactured. Thanks for your response!

Re: Manufacturer of this petrographic scope?

Posted: Thu Nov 28, 2019 2:51 am
by apochronaut
The microscope is Japanese for sure. My guess would be that it might be one made for various retailers such as Lafayette and Edmund. Perhaps few enough were ordered that it didn't make sense to brand them and they may have simply been catalogued as a sort of house brand petrographic.
In Japan , at the time , there were jobbers making various components that the smaller manufacturers could feed off of. It is possible to find very similar brands made by both Carton and Kyowa for instance, two of the more productive stencil manufacturers, that carry the same stage, focus knobs or eyepieces. Either could have made them, or another company.

Re: Manufacturer of this petrographic scope?

Posted: Sat Nov 30, 2019 1:17 am
by billbillt
Hello,
It Is a Unitron from Japan.. I have one here and I like it.. It performs very well with clear, crisp optics....

Re: Manufacturer of this petrographic scope?

Posted: Sat May 09, 2020 3:26 am
by kville79
Nice looking Unitron.

I have a Korean made scope that was obviously made later that appears to be the exact same design, just not as well finished.