Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

What equipment do you use? Post pictures and descriptions of your microscope(s) here!
Message
Author
microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#1 Post by microcosmos » Sun May 29, 2022 1:24 am

I acquired a Zeiss Jena Stativ GCE (1926) as part of my strategic microscopy master plan. Having used automated motorized microscopes with a variety of modern contrast-enhancing and digital imaging technologies, I wanted to allocate some bandwidth to my childhood nostalgia of horseshoe-foot microscopes with plano-concave mirrors and monolithic monocular oculars through which I had first observed the wondrous animalcules with the analogue retina of the human eye, and to continue to nourish my love for microscopy from the “source of the spring”.

Image
New York-JFK to Singapore-Changi International. John F. Kennedy and Nikita Khrushchev saved the world from nuclear war and sent men to the moon and I am always honoured to have my packages fly through JFK.

Image
Made in China.

Image
Carl Hunsinger would cringe to see this.

ImageImage


According to publicly available information from the seller and from Nikon, this instrument was formerly in the collection of Martin Scott FBPA AIMI, consultant in scientific imaging and former director of Scientific Imaging Markets at Eastman Kodak Company. He was also a Nikon Small World judge between the 1970s and 1990s, and co-founded the Rochester Microscopical Society.

I will take more photographs of the microscope as soon as I have the time. Meanwhile I will post some historical and technical information.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#2 Post by microcosmos » Sun May 29, 2022 1:29 am

engineering drawing of Stativ G
engineering drawing of Stativ G
Screenshot 2022-05-03 at 20.59.10.png (434.33 KiB) Viewed 5832 times

Here’s relevant information on the Zeiss Jena G series microscopes, Google-translated from the 1927 catalogue:

The tripod G is our large monocular tripod with ABBE's illumination apparatus and a wide tube, which is provided with an extendable tube and a fixed eyepiece socket. Pull-out tube and eyepiece sockets can be exchanged for each other. The lower end of the tube is either provided with the end plate with the screw thread for the lenses, or instead a large slide guide is attached, in which with suitable slide pieces, for example the revolver, the small slide changer, the vertical illuminator or a single objective can be introduced. Here, too, there is the possibility of conveniently switching between different types of observation. Binocular observation can be made possible by using the "Bitukni" binocular tube attachment instead of the eyepiece connector. Both can be quickly exchanged for each other. The wide tube also enables microphotographic overview shots with planar and similar photographic lenses. The tripod is therefore particularly suitable not only for subjective work, but also for projection and microphotography.

The diaphragm carrier and the iris diaphragm are divided. It is therefore possible to read off the lateral displacement of the iris diaphragm from the centre position and thus to use the iris diaphragm for the production of stereo recordings. Furthermore, the division at the iris diaphragm always allows the diameter of the aperture opening, i.e. to determine the size of the utilized opening of the condenser, and thus the aperture of the illumination. It is the aperture diameter divided by twice the focal length of the condenser, equal to the numerical aperture.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#3 Post by microcosmos » Sun May 29, 2022 1:30 am

Additional information Google-translated from the Zeiss Archiv website:

Bracket tripods with fine movement according to Meyer from 1925

The 1st construction of the fine gear movement according to Meyer was abandoned again relatively soon. Although it had proven to be quite advantageous when working and in use, on the other hand there was a desire to design the cast part (intermediate support) in such a way that it could be processed more efficiently. As early as 1925, the first tripods with this second form and with the fine gear movement according to Meyer left the factory. This form has been unreservedly asserted for a long time and has been well received by both users and other manufacturers. The intermediate carrier has the shape of a circular arc (bow shape) and smooth surfaces on all sides. Such a form can be produced and processed efficiently in an excellent manner.

The tripod G is a large, monocular tripod with a wide tube and is therefore an instrument that can be used without restrictions not only for subjective observations even with the highest demands, but also for microphotographic work and projection, both with the microscope objectives and eyepieces as well as with the weak photographic lenses can be used for overview shots. It is very powerfully built and its design meets modern requirements. It has the complete Abbe illumination apparatus, hence the designation GC. The wide tube is equipped with an extendable tube and a fixed eyepiece connector. The pull-out tube and the eyepiece socket can be exchanged for each other. The lower end of the tube is either provided with the end plate with the screw thread for the lenses, or a large slide guide is attached instead, into which the turret, the small slide changer, the vertical illuminator or a single lens can be inserted with suitable slide pieces. Here, too, there is the possibility of switching between different types of observation. The wide tube enables microphotographic overview shots with planar and similar photographic lenses.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#4 Post by microcosmos » Sun May 29, 2022 1:36 am

Here are photocopied pages from the 1934 catalogue in english that came with the package. The first page bears rubber stamps "PHOTOMICROGRAPHY DEPARTMENT" (possibly where Martin Scott worked) and "JUN 11 1935".

Image

Image
Note that the foot of my instrument is more angular than shown in this image (not sure why - design variation over time?) - see photos of my instrument below.

Image

Interestingly, both the 1927 and 1934 catalogues bear both the old and new ZEISS logos - perhaps it was the transition period.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#5 Post by microcosmos » Sun May 29, 2022 5:20 am

Image

The G stand was born during the Golden Era of the Weimar Republic, in the same year that Germany joined the League of Nations (1926). But before its production ended, the Great Depression had swept across the country and President Hindenburg had enacted emergency powers.

I had a crush on this instrument the moment I saw it - I knew immediately that we were fated to be together. It sits in my sweet spot between too antique-looking and too modern-looking. This particular instrument also has just the right amount of cosmetic wear and tear, making it look like a decorated war veteran.

Here are some examples of the features I was looking for in my dream microscope:

- circular rotating stage. The circle is a beautiful, special shape in both ancient and modern cultures, and I can’t think of a good reason why a microscope stage should be rectangular and unrotatable, besides perhaps cost.

- graceful and bold C-shaped arm of the ideal curvature and thickness. I prefer this to a shouldered arm with an inflection point in the curve that makes it look more old-fashioned and jug-like than I would like, or a triangularish arm that makes the microscope look squat.

- graceful, sweeping incarnation of the horseshoe foot, whose style and weight match the arm.

- the coarse focus knob is in a fixed position, unlike on the D and F stands where it moves up and down so you have to search harder for it and it sometimes hides behind the fine focus knob.

- uses a substage mirror to gather light. Daylight is the most perfect light for observing Nature, and you can boast that your instrument is nuclear-powered since the Sun is a massive nuclear reactor.

- four-objective turret with apochromatic objectives to represent the best period optics available. More objectives means more diversity in industrial design, engineering, optics and functional versatility on a single turret. A three-objective turret also looks like it’s “missing teeth” from certain angles.

- colour scheme. Black, gold and silver are in the correct places, accentuating the structural engineering of the components and of the instrument as a whole. Although I appreciate the utility of plastic and composites where used for the purpose of vibration damping, such as modern composite stands and the plastic focus cogs on the BH2, the all-metal look and feel, especially the brass, is part of the vintage experience.

- the gorgeous large-calibre monocular tube that makes the microscope visually well-balanced top and bottom, besides its intended technical purpose. A binocular tube would look too bulky and modern.

- brass. As apochronaut wrote in another thread,
apochronaut wrote:
Thu Jan 05, 2017 10:51 pm
Brass was the material of choice for important castings , sacrificial parts and those at risk of corrosion on the finest instruments. It provided weight to the instruments, conferring stability and in pairings such as dovetails and rack and pinion sets the more easily replaceable of the two could be made of the slightly softer than steel, brass, so that the more labour intensive to replace part, such as the pinion gear, could remain in good shape. If both the rack and pinion were steel, then both would wear. Brass is also relatively non-corrosive, an important feature in labs where gases and reagents might be in abundance. In some cases two very similar instruments, one average and the other research grade, would be partially distinguished by the lesser having a cast iron base and the latter having a heavier cast brass base. Brass is expensive and sadly, the extreme competiion that emerged in the 1960's in the microscope industry, spelled the death knell of the use of brass and bronze components in all but the very best and costly instruments. Stainless steel has replaced it in some applications where corrosion resistance is of importance.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#6 Post by microcosmos » Sun May 29, 2022 5:24 am

Image
My "Saturn V" Olympus BHSP side-by-side with the Zeiss Jena Stativ GCE.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#7 Post by microcosmos » Sun May 29, 2022 5:25 am

Image

The lettering seems to be inlaid with a grey-silver metal so as to give a flat surface, rather than just engraved.

If someone has access to Lawrence Gubas’ book with the serial numbers, I will be grateful to have the exact year in which this stand Nr. 180096 was made, in order to celebrate its centenary in a few years’ time.
Last edited by microcosmos on Sun May 29, 2022 6:51 am, edited 1 time in total.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#8 Post by microcosmos » Sun May 29, 2022 5:32 am

Olympus Homare UCE
Olympus Homare UCE
Screenshot 2022-05-03 at 21.01.15.png (436.24 KiB) Viewed 5803 times

In 1935, nine years after the advent of the Zeiss GCE, Olympus released its Homare UCE (above).

It is near-identical to the Zeiss in almost every detail. The foot is not as graceful as the Zeiss, but its curved rear looks wider and possibly more stable than the Zeiss.

Olympus marketed it as a high-end microscope with a solid design suited to photography - very similar to the Zeiss.

According to https://www.explorebabynames.com/meaning-of-homare, "Homare" is a boy’s name that signifies honour, glory and renown.

In another thread, apochronaut offers some insights on the copying and adaptation of the designs of microscopes of the period:
apochronaut wrote:
Fri Aug 30, 2019 3:28 pm
The post W.W.II Japanese companies, and not just those related to optics were quite schizophrenic when it came to their designs. While they freely swiped whatever designs they could from the Germans during that period when patent restrictions applied to them, they were also flooded with American goods during the Showa period of occupation. Design influences were many.

The early designs of Shintaro Terada, for M & Katera, used either total knockoffs of Leitz objectives, or they were made outright by Leitz; such is their similarity, right down to the upside down logo and stamped specs., a unique feature of Leitz at the time. When he started designing for Olympus around 1919, the objectives on their early microscopes appear to be identical. M & Katera, eventually became Tiyoda but Shintaro Terada was the chief engineer for both of those startups.

One odd feature of post W.W. II Olympus , is the weird 36.5+ mm parfocal distance, which that UCE probably has. There is no doubt that Bausch & Lomb microscopes were pretty common in Occupied Japan and they curiously had a parfocal distance of 1-7/16" until the flat field era came out of Rochester. 1-7/16" is just over 36.5mm.
I am guessing that a close examination of the early post W.W. II microscopes from many companies would show a little bit of this and a little bit of that.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#9 Post by microcosmos » Sun May 29, 2022 5:37 am

Katera MKC
Katera MKC
katera-MKC-1.jpg (68.77 KiB) Viewed 5791 times

Another close copy of the Zeiss GCE was the Katera MKC (link kindly given by apochronaut in another thread), but this one has a narrow tube more akin to the lower-end Zeiss Stativ E series.

In another thread, apochronaut gives some insights into the indirect design connections among Katera, Zeiss and others:
apochronaut wrote:
Fri Jul 26, 2019 11:50 am
Tiyoda had a somewhat bouncy start. The precursor M & Katera had an association with Leitz. Early M & Katera objectives are so close to Leitz objectives as to be knockoffs. They in fact may have been made by Leitz, or possibly the lenses, so they were 37mm parfocal. Later, after the company had morphed into Tiyoda( another partner in M & Katera became Olympus), they seemed to benefit from some sort of political agreement with Germany and the influence shifted to be from Zeiss. The objectives seem to be more in an older Zeiss style at least, and there is evidence of some parts being identical to Zeiss parts.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#10 Post by microcosmos » Sun May 29, 2022 5:56 am

Some initial engineering inspections and works:

ImageImage
Bent stage centering pin. The pin appears to be made of steel, with a rounded tip. The thread is non-standard gauge with outer diameter 3.4 mm and pitch 0.5 mm. The closest standard threads are 3/0.5 or 3.5/0.6. This means that the Zeiss pin is unusually fat and finely threaded. This gives especially fine control over the axial movement of the pin when it is turned (the fat finger knob further enhances fineness of control). This is an example of good design if we consider that very fine control is needed when centering the axis of rotation of the stage to the field of view of a high-powered objective (for purposes like extinction angle measurements in petrographic polarizing microscopy).

Image
Tightening the internal snake-eye threaded ring in the nosepiece that connects to the threaded bottom (visible as smaller-diameter ring) of the tube.

ImageImage
The coarse focus rack and pinion.
Last edited by microcosmos on Sat Jun 11, 2022 8:40 am, edited 4 times in total.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#11 Post by microcosmos » Sun May 29, 2022 6:26 am

This post is about the ocular and the ocular tube.

ImageImage

Does anyone have more information on the origin of this hyperplane 15x eyepiece? I read from other threads and websites that this kind of eyepiece is usually attributed to Bausch & Lomb, partially corrects lateral chromatic aberrations and field flatness, and helps to mitigate the poor planarity of early objectives. It is therefore good for photomicrography.

I was hoping to insert a cross-scale reticle/graticule but it looks like it doesn't have an easily removable aperture on the back. Nor can I seem to unscrew or remove the upper knurled part. Does anyone know if it is possible to insert a graticule in this eyepiece?

Image

The upper part of the tube unscrews to reveal a narrower extendable inner tube with tube length graduations going to a max of 210 mm. The bottom of the inner tube seems to be missing an extension (see schematic in the second post in this thread) and has an inner screw thread presumably for that - does anyone know what the missing part does? The inside surfaces of both the outer and inner tubes have a matt black finish to reduce stray light.

Image
Set to 160 mm mechanical tube length. There are no set screws to hold it in place, just precision-engineered friction.
Last edited by microcosmos on Sun Jun 26, 2022 8:11 am, edited 1 time in total.

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#12 Post by MicroBob » Sun May 29, 2022 6:50 am

Congratulations, you've got a very nice instrument there!
For more information you might contact the Zeiss archive: https://www.zeiss.de/corporate/ueber-ze ... rchiv.html
I have somewhat older model 53xxxx which I was able to date to 1911 by comparison with information found here: https://www.musoptin.com/item/reisemikr ... 4087-1929/

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#13 Post by microcosmos » Sun May 29, 2022 7:20 am

Thank you! I love it and want to share the exploration and discovery with anyone who’s interested.

I will try contacting the Zeiss archives. Hopefully they have the order book record for my instrument and are willing to answer. They put up some of that information online but, of course, it stops before my year.

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#14 Post by MicroBob » Sun May 29, 2022 7:28 am

Much of their information is in paper form and they are unwilling to scan it, you can only go there and look at it in person.
In the delivery list for their first instruments I found an interesting fact: The first instrument went to Hamburg, my birth town, to a member of the "Naturwissenschaftliche Gesellschaft", which was a branch of the "Naturwissenschaflicher Verein" which I am a member of today.

Here I have showed my instrument: viewtopic.php?f=11&t=7247&p=64042&hilit ... 911#p64042

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#15 Post by microcosmos » Sun May 29, 2022 8:08 am

Even though they can’t scan it, hopefully they can tell me over email what’s written for my serial number.

Unfortunately I have no connection with Hamburg or the Naturwissenschaftliche Gesellschaft, but I can play my favourite Bruckner and Mahler symphonies by the Wiener Philharmoniker and Berliner Philharmoniker while I am enjoying the microscope!

Your microscope seems to be my dad! I do like your objective turret design even though it’s probably too retro for my instrument.

The vertical part of your Bitukni eyepiece has a narrower section of tube at the very bottom. What does that do? Does it have a lens?

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#16 Post by microcosmos » Sun May 29, 2022 11:55 am

Continuing with my inspection -

The four apochromat objectives are like jewels with their finely knurled rings and specs engraved in an engineering-typewriter font. They look like real objectives compared with the printed Arial font on modern objectives that look as if they were typed out in Microsoft Word, which disturbs me so much that I was forced to wrap the objectives on my other microscope in black gaffer tape (see earlier picture of it alongside the GCE).

Image
Image
10x/0.30, 20x/0.65 (0.17 coverslip), 40x/0.95 and immersion objective with no magnification or NA indicated.

Image
Inscriptions on the other side. The 40x's coverslip correction collar is engraved with exquisite graduations, with a small but clear black triangle indicator pointer on the barrel. The collar surface is flush with the objective barrel, which minimizes parallax error when reading off the coverslip correction.

Image
In contrast, many modern objectives, even this top-end Zeiss C-apochromat 63x/1.2, have a protruding collar which makes it more difficult to get a parallax-free reading of the coverslip correction, especially when the objective is mounted on a nosepiece and one may have to read it off from an angle. In the objective shown above, the markings on the collar don't even go all the way to the edge of the collar, making it even more error-prone.

Image
The 40x objective has a spring inside the rear aperture that appears to be for a spring-loaded tip, but I can't get the tip to compress. Perhaps it's stuck.

The lenses are uncoated, which pleases me in the same way as natural food with no artificial colourings or flavourings. In another thread apochronaut highlights the challenges of using these uncoated apochromats:
apochronaut wrote:
Sun May 01, 2022 11:05 pm
Early uncoated apochromats for instance had finely defined borders and in order to maximize contrast the condenser needed to be achromatic and very critically adjusted : so much so that some research microscopes had both a coarse and fine focus on the condenser.
Some of the glass on these objectives may have come from the mountains:
apochromat wrote:
Mon Jan 10, 2022 11:56 am
The apochromatic colour correction was invented by Ernst Abbe in 1886 using natural calcium fluoride and new glass types from Otto Schott. Abbe himself learned to mountain climb and from this large calcium fluoride finding in the suisse Oltschi Alp mountains all apochromats from ZEISS where made until the 1920ies. The first microscope objective with only one fluoride lens element within the optical design was invented in 1893 by Rudolf Winkel in Göttingen (which is still the ZEISS- factory for the high-end microscope objectives). Rudolf Winkel called it "Fluorite" objective and it became enormously popular fast. The first anti-stray-light coated fluorite objectives where made after WW II by R. WINKEL GmbH (fully owned by ZEISS since 1911) in 1953 and called the NEOFLUAR since then.
There's even a photo of Ernst Abbe himself looking out of a mountain hut in this Zeiss magazine.
Last edited by microcosmos on Sun Jun 12, 2022 12:53 am, edited 3 times in total.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#17 Post by microcosmos » Sun May 29, 2022 1:08 pm

Image
Image

Visually the oil immersion objective seems to be encased in copper and brass with nickel-plated tarnishable tip.

It’s unscrewable (what an ambiguous word!) into two parts, perhaps the part adjoining the turret serving as a low-power dry objective. I’ll see what it does when I get to the operational deployment phase of this instrument.

It’s inscribed “Homog. Immers. Tubusl. 160mm”. Homogeneous immersion was an early term meaning that the refractive indices of the objective front lens and immersion liquid were matched for the centroid wavelength (see Zeiss magazine). Tubuslange means tube length.

No magnification or NA is inscribed. However, the earlier owner helpfully underlined the 90x/1.3 option in the photocopied specs (see images earlier). However, the objective I have seems to be of an older design than the objectives illustrated in the 1927 catalogue. Unlike the 40x, there’s no correction ring for coverslip, supporting the suspicion that it is of earlier vintage. In fact it looks like a c. WWI Zeiss objective shown by apochronaut in another thread:
apochronaut wrote:
Tue Sep 14, 2021 1:03 am
A representative collection of circa W.W. I high power objectives, all of which appear to have a nickel plated tip. At least the plating seems to tarnish in a fashion similar to the way nickel does.
From left to right.
1) Bausch & Lomb.
2) Voigtlander
3) Bausch & Lomb
4) Zeiss
5) Schutz- Kassel
Image

Additional references for objectives:

detailed history of early Zeiss objectives and early microscope objective development in general

Fritz Schulze’s article on chemically corroded glass in century-old Zeiss apochromats

PeteM
Posts: 2982
Joined: Tue Dec 06, 2016 6:22 am
Location: N. California

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#18 Post by PeteM » Sun May 29, 2022 4:26 pm

Interesting scope. The large tube was important enough to get mention in the literature you've shown - I'm curious what purpose it had?

As for your bent knurled screw, your best bet (failing finding a donor scope) may be to measure the thread and either buy or have a replacement machined. You could keep the knurled end for an OEM look, remove the threaded portion and drill it to receive the new thread, glued or brazed in place.

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#19 Post by MicroBob » Sun May 29, 2022 8:36 pm

PeteM wrote:
Sun May 29, 2022 4:26 pm
Interesting scope. The large tube was important enough to get mention in the literature you've shown - I'm curious what purpose it had?
Hi Pete,
do you mean the diameter of the tube above the nosepiece? I think it helps to increase contrast by cutting down reflections and underlines the visual impression of being a professional model.

Bob

PeteM
Posts: 2982
Joined: Tue Dec 06, 2016 6:22 am
Location: N. California

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#20 Post by PeteM » Sun May 29, 2022 9:02 pm

Thanks, Bob. The notion that a larger tube might have fewer reflections, even with the usual blackening inside, makes sense (if partly as a sales point to go along with that more professional look).

MicroBob
Posts: 3154
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#21 Post by MicroBob » Mon May 30, 2022 1:14 pm

I had a look into my tube: It is this typical oldfashioned blackened brass with no light baffles in it. But they may have been removed when the bino tube was attatched.
The bino tube has a lens right at the bottom. The physical length of the bino tube is longer than 160mm so this has to be compensated.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#22 Post by microcosmos » Mon May 30, 2022 1:27 pm

MicroBob wrote:
Sun May 29, 2022 8:36 pm
PeteM wrote:
Sun May 29, 2022 4:26 pm
Interesting scope. The large tube was important enough to get mention in the literature you've shown - I'm curious what purpose it had?
Hi Pete,
do you mean the diameter of the tube above the nosepiece? I think it helps to increase contrast by cutting down reflections and underlines the visual impression of being a professional model.

Bob
Thank you Bob and Pete for your ideas.

It seems that much of any stray light exiting the objective will enter the intertube space and get trapped and attenuated there before it can enter the bottom of the inner tube, and the inner tube itself is also wider than is necessary so it further removes residual stray light. If this is what this setup is actually doing, I think it’s quite clever.

I have several options for rectifying the bent stage centering pin, thanks to suggestions by fellow microscopists, and will report back when I get to fixing it.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#23 Post by microcosmos » Mon May 30, 2022 1:31 pm

MicroBob wrote:
Mon May 30, 2022 1:14 pm
I had a look into my tube: It is this typical oldfashioned blackened brass with no light baffles in it. But they may have been removed when the bino tube was attatched.
The bino tube has a lens right at the bottom. The physical length of the bino tube is longer than 160mm so this has to be compensated.
Kind of relieved to hear this, as it probably means that the missing bottom attachment on my inner tube isn’t a big problem since I’m using a short monocular eyepiece. But the narrowness of the bottom attachment probably helps further cut out stray light as well.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#24 Post by microcosmos » Sat Jun 04, 2022 6:52 am

Image
The exquisite “large XY stage E” is rotatable with no brake as far as I can tell. There is no goniometer, which would have been good for measuring angles. I might try designing and attaching one at a later date. The lever at upper right is for braking the y-movement of the slide holder to prevent it from creeping due to gravity when the stage is inclined.

Image
BOING!!! The spring-loaded screw that holds the rotating bracket is stripped so the stage is currently not fully centerable as I have to immobilize it using the centering screws. The spring-loaded screw should have been made with deeper and more threads.

Image
I love the vernier scales which I use to recall the exact positions of interesting features on fixed slides. According to the Zeiss specs, the preparation can be adjusted 30 mm forwards and 50 mm sideways. There are actually three vernier scales labeled I, II and III - see this Facebook thread for discussion.

In another thread, apochronaut gives some insight on stages on old microscopes:
apochronaut wrote:
Tue Sep 14, 2021 2:38 am
Many older quality stands had multitudes of stage options , from simple clips to very precise and intricate circular revolving models. Having a fine stage, sets these older gems on another plane, something average modern microscopes cannot easily attain without a massive cash outlay.
Last edited by microcosmos on Sun Jun 26, 2022 8:08 am, edited 2 times in total.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#25 Post by microcosmos » Sat Jun 04, 2022 7:09 am

Screenshot 2022-05-03 at 20.55.02.png
Screenshot 2022-05-03 at 20.55.02.png (107.41 KiB) Viewed 5475 times
Image
Image
The condenser is a three-lens aplanatic of NA 1.4 and focal length 10.5 mm. According to the 1927 catalogue, “the upper part with the two upper lenses can be unscrewed. The lower lens alone then forms an aplanatic condenser with a focal length of 37 mm, numerical aperture about 0.4” (for weak objectives). Unfortunately it has no fine focusing knob. What appears to be dried Canada balsam cement has flaked/chipped off and fallen onto the top of the lower lens of the upper group.

Image
The swing-out condenser aperture diaphragm (12-bladed) for oblique illumination has rotational and translational controls that enable it to be offset in any direction. I can’t seem to find descriptions or specifications in the catalogue and am still digging for information - I would welcome any references.

Image
It has a spring-loaded appendage that clicks smoothly into the centered home position (although you still have to retract the translational dovetail, which also has a home position click stop, to get the aperture fully centered).

Image
Underside of the 12-bladed diaphragm seen via the mirror.

In another thread, apochronaut gives insights on oblique illumination:
apochronaut wrote:
Fri May 20, 2022 2:20 am
Oblique illumination was as common to research microscopes from the 1870's until the advent of phase microscopy as was the colour black. It was the D.I.C. of that era and when artfully mastered could be almost as good. Many of the discoveries made by 19th century diatomists and bacteriologists were made with oblque and every manufacturer of note designed fantastically precise, graduated oblique diaphragms for. their stands.
Last edited by microcosmos on Sun Jun 26, 2022 8:15 am, edited 3 times in total.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#26 Post by microcosmos » Sat Jun 04, 2022 11:59 am

After some deliberation, I've decided on the official theme music for my microscope:

Anton Bruckner · Symphonie IX
Wiener Philharmoniker · Herbert von Karajan
Großer Saal, Musikverein · 1978

https://youtu.be/6CEiZ7DTVZ8

I will soon take the microscope on its sea trials and shakedown cruise, and embark on a quasi-Leeuwenhoekian journey through the microcosmos.

Charles
Posts: 1424
Joined: Mon Mar 02, 2015 11:55 pm

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#27 Post by Charles » Sat Jun 04, 2022 7:25 pm

Zeiss G 180001-180600 June 1926
Attachments
Zeiss G Stand.JPG
Zeiss G Stand.JPG (64.11 KiB) Viewed 5411 times

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#28 Post by microcosmos » Sun Jun 05, 2022 1:30 am

Thank you very much for the information. Now I can celebrate its centenary. Queen Elizabeth II may also be interested to know that she was only two months old when this microscope was made.

I have also written to Zeiss Archives to ask if they have any information from their production and dispatch lists.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#29 Post by microcosmos » Sun Jun 05, 2022 7:25 am

I've verified physically that the ocular tube is 23.2 mm and the objective threads are RMS. These standard specs make the instrument more powerful and versatile as you can use any of the finite RMS objectives and matching eyepieces, and the tube length is adjustable. For example they fit my Nikon CFWN and Plan Apochromatic 20/0.75 perfectly.

ImageImage
(The second picture shows critical (Nelsonian) illumination in action, using a frosted Philips 2700 K LED with a CRI > 90, which makes it very close to a real incandescent lamp in its colour spectrum, thereby reproducing specimen colours as closely as possible. Apologies for the bad placement of the lamp - this was a quick and dirty setup as it's still the "sea trials" period.)

You could even use infinity objectives if you really wanted to - the fat tube has internal structures that would make it possible to mount a tube lens inside.

To me, this is good design and engineering.

microcosmos
Posts: 252
Joined: Fri Jun 18, 2021 9:05 am
Location: Singapore

Re: Zeiss Jena Stativ GCE 1926: history, design, materials, workmanship, optics

#30 Post by microcosmos » Sun Jun 05, 2022 10:54 am

Image
Something on one of the inner lenses of the eyepiece - is this delamination? I can't remove it with isopropanol and lens paper.

Here are the very first micrographs, of the most classic slide in my collection - a badly prepared Allium root l.s. by none other than yours truly when I was in high school. I'm feeling like Leeuwenhoek all over again.

Image

Image
10x/0.30 objective.

Image
20x/0.65/0.17 objective.

Taken with a Ricoh GRII through the 15x hyperplane eyepiece under critical illumination with a 2700 K frosted Philips LED of CRI > 90. Pardon the absence of a daylight filter and the lax control of exposure. The lower lens of the eyepiece has a stain along part of its circumference which I will try cleaning up later. The objectives are quite apochromatic as advertised, with very slight CA and the expected nonplanarity (the camera lens added more nonplanarity; it looks flatter through the naked eyepiece). Further disclaimers: the optics are not completely clean yet. I'm still not sure if the eyepiece is meant for these objectives. I'm not sure if the adjustable tube length of the tube is at 160 mm - the graduations on the inner tube read 183 where they meet the sleeve holding the inner tube; I can't slide the tube (it seems to be stuck) - will look into freeing it later.
Last edited by microcosmos on Sun Jun 12, 2022 9:16 am, edited 1 time in total.

Post Reply