This is description of this part:
Objective with 2.5x magnification and T anti-reflective coating for the Carl Zeiss Jena PM XVI stereo microscope.
Basic information:
Objective type: for stereo microscopes, a so-called "objective pair"
Magnification: 2.5x
Anti-reflective coating: yes, this is an objective carrying the red letter "T", i.e. T-coated
On the black plastic housing the magnification is written as "2,5" - unlike the older versions of such objectives (made for the Stereomikroskop XII model), where the format used was "2 1/2" (see here: https://www.microscopeparts.eu/part/91035)
In stereo microscopes built on the Greenough principle, what is called "the microscope objective" is in fact a pair (two pieces) of objectives set at a specific angle to each other. This is exactly why the housings of older examples of such objectives (more precisely: the common housing covering the pair of objectives) carried two serial numbers. Each of these objectives simply had its own individual serial number. Such a case can be seen on this 1.25x objective: https://www.microscopeparts.eu/part/00654.
This technical design has a very interesting consequence - each single objective, once taken out of the housing, becomes an interesting choice for anyone working in macro photography, all the more so because these are usually low-magnification objectives, which are exactly what macro photography looks for.
Since the 1930s Carl Zeiss Jena has produced many models and variants of stereo microscopes, and this objective will fit the vast majority of them, because the way they are mounted is the same throughout.
Several names are in use on the market for the stereo microscope this objective comes from:
- Carl Zeiss Jena Stereomikroskop XVI
- Carl Zeiss Jena Präpariermikroskop XVI
- Carl Zeiss Jena Stereomikroskop PM XVI
- Carl Zeiss Jena SM XVI
- Carl Zeiss Jena PM XVI
Sometimes, to avoid Roman numerals, you also come across the spellings "SM-16" and "PM-16".
Interestingly, in the instruction manual from 1954 available online (https://www.microscopemuseum.eu/catalogues/Carl_Zeiss_1954_Stereomikroskop_PM_XVI.pdf), the header on page 3 reads "Stereomikroskop PH XVI". I do not know whether this is an OCR error or an original misprint, but it means that this (incorrect) name may be in circulation as well - and all of the names listed above refer to one and the same microscope.
What is this part needed for?
- if you own such a microscope without objectives and therefore need at least one objective
- if you need an objective to replace a damaged one, or if your current objective is in very poor condition
- if you have a microscope with objectives of other magnifications and want to have them all
- if you already have a 2.5x objective but without the anti-reflective coating and want one that has it
