Spencer 10x Compens Eyepiece

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J_WISC
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Joined: Sun Mar 06, 2022 7:28 pm
Location: Wisconsin, USA

Spencer 10x Compens Eyepiece

#1 Post by J_WISC » Sun Mar 05, 2023 7:16 pm

Hello.

I have a single Spencer 10x compens eyepiece. If I want TWO to use on a binocular microscope, do I need one more just like the one I have or do I need a matched pair? There's a letter C on the barrel of the one in the attached photo. Does that mean it was likely separated from its partner or does it stand for "compens"? Thank you for all the information you all provide.

eye single 10x AO compens top smaller.jpg
eye single 10x AO compens top smaller.jpg (172.82 KiB) Viewed 389 times
eye single 10x AO compens side smaller.jpg
eye single 10x AO compens side smaller.jpg (192.74 KiB) Viewed 389 times

By the way, this eyepiece works quite well with a 50x (estimated from relative field of view) apochromatic objective and a suspected pol objective (apochronaut: the black enamel one you sent). I might want a pair of 12x or 15x if they're out there.

apochronaut
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Joined: Fri May 15, 2015 12:15 am

Re: Spencer 10x Compens Eyepiece

#2 Post by apochronaut » Mon Mar 06, 2023 2:07 pm

The eyepiece you have is one from the last production and was made for use with the brushed chrome apochromats that carried the colour coded rings prior to their universal adoption by the industry. They must have tweaked them somewhat, because those eyepieces are very different from the previous 10X compens. You must have one of the same physical design to match. Even the eyelens diameter is different.
The C on the barrel probably means that it has a magnesium fluoride coating. A pair I have has a matching serial# beginning with a C, implying , coated. An eyepiece made for use on a monocular would not require a matched serial # but still would require a "coated" designation at the time because it was an option until the infinity era began around 1962.


AO began colour coding objectives in the early 30's, initially with a thick black band around the high power oil immersion objective, then in the late 1940's, enamelling thin engraved grooves around the objective perimeter. Low power, no code, 16mm/10X, green : 8mm/20X,blue : 4mm/43X,yellow : 1.8mm/97X, red. An extra thick red ring was added for special purpose objectives, pol for instance. Later, into the infinity era, they adopted purple for 2.5X, black for 4X and a kind of dark red for 50X. In the beginning of the concept, companies chose their own colours. , B & L used white for 50X and blue for 4X for instance.
With the introduction of the series 400 microscopes in 1985 and the new 45mm objective barrels, AO/Reichert switched to conform to what was becoming an international objective colour code standard.
The code is : none= 1/2X, black= 1 to 1.5X, brown= 2 to 2.5X, red= 4 to 5X, yellow= 10X, green= 16 to 20X, light blue= 40 to 50X, dark blue= 50 to 70X, and white= 100X and up.

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