Home page of the microscope service parts, repair and spare parts online catalog - Sermik-Oplatek Mikroskopservice Dresden f.n.n.Z

Description of this part for the microscope.

operation of 1 objective at a time - this is not a objective turret (revolver)
- the adapter allows work in brightfield mode
- the adapter does not support objectives with RMS thread (approx. 20 mm)

Description of this part for the microscope.

The photos show the exact dimensions of this item.

Description of this part for the microscope.

microscope objective
- Manufacturer: Carl Zeiss Jena
- Designation: Planachromat 25x/0,50 oo/0,17
- Magnification: 25x
- Numerical aperture N.A.: 0,50
- Optical correction: infinity-corrected tube length
- Optical correction class: planachromat
- Cover glass: yes, 0.17 mm
- Thread: M19

Some facts about Carl Zeiss Jena objectives with M19 thread (CZJ M19) and their compatibility with various microscopes from this manufacturer:
- these objectives are most commonly used for technical applications rather than biological applications, therefore most objectives available on the secondary market are intended for use without a cover glass (designation oo/0)
- CZJ M19 objectives intended for biological applications (designation oo/0,17) are most commonly used on Carl Zeiss Jena NU / NU2 microscopes
- in Carl Zeiss Jena Nf and Lumipan microscopes, CZJ M19 objectives are used together with an EPI illuminator
- CZJ M19 objectives can be used in Carl Zeiss Jena Polmi-A microscopes, but they provide a different magnification than the nominal value
- Carl Zeiss Jena Amplival / Amplival Pol / Amplival Interphako / Peraval microscopes feature interchangeable nosepieces, and a dedicated nosepiece for M19-thread objectives was also produced for these microscopes
- Carl Zeiss Jena Metaval and Neophot microscopes use newer versions of CZJ M19 objectives (with a coarse-knurled edge and shiny housing), although many users still experiment with older M19 objectives on these microscopes
- Carl Zeiss Jena Epignost and BK 70x50 microscopes were produced in various versions with completely different configurations - and some of them operate with CZJ M19 objectives
- Carl Zeiss Jena Vertival / Epival / Nf / BK 70x50 microscopes often allow the use of CZJ M19 objectives in EPI dark-field mode
- on the Carl Zeiss Jena Epityp-2 inverted metallurgical microscope, many users employ biological objectives designed for use with a cover glass, placing the microscope slide "upside down", with the cover glass facing downward toward the objective.

Description of this part for the microscope.

Gleitfett grades differ in their parameters.

Gleitfett I E10 and Gleitfett II E75 were supplied with the Carl Zeiss Jena micromanipulator.
The Gleitfett III E410 offered here was supplied with the Carl Zeiss Jena Neophot-21 microscope.

This MAY suggest (although I have no proof in the form of manufacturer documentation) that the lower numbers (I and II) and the lower values of the "E" parameter (E10 and E75) were intended for finer mechanisms - and may therefore have a lower viscosity, for example. The III E410 grease, with its high "E" value, was supplied with a heavy microscope built around massive mechanics - so it may well be thicker.

This grease can of course be used on microscopes from other manufacturers as well - a few are listed in the "compatibility" section, but that is by no means a complete list.

Description of this part for the microscope.

be attached to a trinocular head or directly to the microscope body, even when there is no trinocular head.

Basic technical parameters of this tube:
Manufacturer: Carl Zeiss Jena
Colour: grey
Tilt angle: none, this is a straight tube
Internal optics: none - not even a deflecting prism
Mounting to the trinocular head or microscope body: ring with a dovetail
Dovetail diameter: 41 mm
Type of connection at the output: empty tube / barrel
Tube diameter at the output: 23.2 mm internal diameter
Length of the barrel / tube: 25 mm
Length adjustment: no - this is not a tube with adjustable height

Since the adapter has an empty barrel with an internal diameter of 23.2 mm on the output side, a projection eyepiece of that diameter can be placed in it, or a so-called "USB eyepiece", that is a digital microscope camera. Adapters between the 23.2 mm barrel and the M42 thread are also widely available, and from the M42 thread you can move on to any other mount: Nikon, Canon, Sony and others.

Such a tube can be mounted directly on the microscope body instead of the head. A dovetail seat with a diameter of 41.0 - 41.5 mm is found, among others, on the microscopes:
- Carl Zeiss Jena
- LOMO
- Meopta
- IOR
- Reichert Biopan
- Olympus CH

It is also often used in microscopes with a slightly larger seat, among others Zeiss West Germany, Leitz Wetzlar, PZO, Will Wetzlar, Hund Wetzlar.

The adapter can equally well be fitted onto trinocular heads, as many of them have a seat prepared for it, among others:
- the output in the trinocular tubes of the Carl Zeiss Jena Jenamed, Jenaval, Jenalumar, Jenatech, Jenavert, Jenapol microscopes
- the LOMO TRN-1 heads (ЛОМО ТРН-1), found in the LOMO Polam microscopes
- some versions of the intermediate photo tubes for the Carl Zeiss Jena Mikroval series microscopes (others require a tube screwed onto a thread)

This is not a "tube for one specific microscope model". A trinocular head can be mounted not only on the microscope it was sold with - it is therefore correct to assume that this is a universal tube, with a 41 mm dovetail on one side and a 23.2 mm barrel on the other.

The "compatibility" section gives an example list of microscopes this tube fits, although it is not a complete list.

Description of this part for the microscope.

The tube allows a camera or a camera body to be attached to a trinocular head or directly to the microscope body, even when there is no trinocular head.

Basic technical parameters of this tube:
Manufacturer: LOMO (ЛОМО)
Colour: black, rings and barrel chrome-plated
Tilt angle: none, this is a straight tube
Internal optics: none - not even a deflecting prism
Mounting to the trinocular head or microscope body: ring dovetail (male part)
Dovetail diameter: 41 mm
Type of connection at the output: empty tube / barrel
Tube diameter at the output: 23.2 mm internal diameter
Length of the barrel / tube: variable
Length adjustment: yes - the barrel is extendable, with a scale from 140 to 200 mm and a knurled locking ring

This is the version with adjustable tube length. A scale from 140 to 200 mm is engraved on the extendable barrel, with a reference line and intermediate divisions, and the setting is locked with a knurled ring. This gives two things at once. First, a continuous change of the image scale - the longer the tube, the larger the image falling on the sensor or the film, so the framing can be adjusted without changing the objective. Second, and more importantly, the ability to work with objectives computed for different optical tube lengths: 160, 170, 180, 190 and 200 mm. Carl Zeiss Jena and LOMO objectives are computed for 160 mm, Leitz Wetzlar for 170 mm, some objectives of metallurgical and measuring microscopes for 190 or 200 mm - here you simply set the barrel to the right value and the objective works under its design conditions, instead of delivering an image with residual aberration.

Since the adapter has an empty barrel with an internal diameter of 23.2 mm on the output side, a projection eyepiece of that diameter can be placed in it, or a so-called "USB eyepiece", that is a digital microscope camera. Adapters between the 23.2 mm barrel and the M42 thread are also widely available, and from the M42 thread you can move on to any other mount: Nikon, Canon, Sony and others.

Such a tube can be mounted directly on the microscope body instead of the head. A dovetail seat with a diameter of 41.0 - 41.5 mm is found, among others, on the microscopes:
- LOMO
- Carl Zeiss Jena
- Meopta
- IOR
- Reichert Biopan
- Olympus CH

It is also often used in microscopes with a slightly larger seat, among others Zeiss West Germany, Leitz Wetzlar, PZO, Will Wetzlar, Hund Wetzlar.

The "compatibility" section gives an example list of microscopes this tube fits, although it is not a complete list.

The last photo shows a LOMO Erudit microscope with this photo tube and a projection eyepiece mounted. It is an example of use.

Description of this part for the microscope.

Carl Zeiss Jena
Engraving on the objective: Planachromat 25x/0,50 ∞/0
Magnification: 25x
Numerical aperture N.A.: 0,50
Free working distance: 3,1 mm
Tube length: infinity (more precisely: 250 mm)
Optical correction: planachromatic
Cover glass: no - this objective is intended for work without a cover glass
Immersion: no - this is a so-called dry objective
Phase contrast: no - this objective has no phase ring inside
Polarisation: no - this is not a polarising objective
Thread: M19
Plan compensating eyepieces: yes, required - this objective calls for eyepieces with additional correction (designated "PK" by Carl Zeiss Jena)
Direct projection and macro photography: no - this objective does not work in direct projection mode and is not suitable for macro photography by connecting the objective directly to a camera

This objective can be used as:
- an objective for work in reflected light (EPI), for biological as well as, among others, metallurgical or mineralogical applications
- an objective for work in transmitted light, among others with biological specimens or, for example, with mineralogical thin sections

A few facts about Carl Zeiss Jena objectives with M19 thread (CZJ M19) and their compatibility with various microscopes of this company:
- these objectives serve mostly technical applications and are intended for work without a cover glass (marking ∞/0)
- CZJ M19 objectives intended for biological applications (that is, marked ∞/0,17) are most often used on Carl Zeiss Jena NU / NU2 microscopes
- in Carl Zeiss Jena Nf and Lumipan microscopes, CZJ M19 objectives are used together with the EPI illuminator and can then work both in bright field and in dark field
- in Carl Zeiss Jena Polmi-A microscopes, CZJ M19 objectives can be used, but they give a magnification other than the nominal one
- Carl Zeiss Jena Amplival / Amplival Pol / Amplival Interphako / Peraval microscopes have an interchangeable nosepiece, and there is also a nosepiece intended for these microscopes that accepts objectives with M19 thread
- Carl Zeiss Jena Metaval microscopes use newer versions of CZJ M19 objectives (those with a coarsely knurled rim and a glossy barrel), yet many people experiment with older M19 objectives on these microscopes
- Carl Zeiss Jena Epignost and BK 70x50 microscopes were produced in various configurations - and some work with CZJ M19 objectives
- Carl Zeiss Jena Vertival / Epival / Nf / BK 70x50 microscopes often allow work with CZJ M19 objectives in EPI dark field mode
- on inverted metallographic Carl Zeiss Jena Epityp-2 / Neophot-21 microscopes, many people use biological objectives intended for work with a cover glass alongside metallurgical ones, and place the slide with the specimen on the stage "upside down", that is, with the cover glass facing downwards

Description of this part for the microscope.

21 microscope.

Basic parameters:
Manufacturer: Carl Zeiss Jena
Engraving on the objective: Planachromat 25x/0,50 ∞/0 Ph
Magnification: 25x
Numerical aperture N.A.: 0,50
Tube length: infinity (more precisely: 250 mm)
Optical correction: planachromatic
Cover glass: no - this objective is intended for work without a cover glass
Immersion: no - this is a so-called dry objective
Phase contrast: yes, a special phase contrast for work in reflected light
Polarisation: no - this is not a polarising objective
Thread: M19
Plan compensating eyepieces: yes, required - this objective needs eyepieces with additional correction (marked "PK" at Carl Zeiss Jena)
Direct projection and macro photography: no - this objective does not work in direct projection mode and is not suitable for macro photography with the objective attached directly to a camera

Phase contrast objectives for the Neophot microscopes have a phase ring built differently from the other Ph objectives made by Carl Zeiss Jena - instead of a continuous ring there is a three-segment pattern, somewhat reminiscent of a Wankel engine rotor. This is worth knowing, because it means that a phase contrast objective from a biological microscope will not replace this one in a Neophot, and the other way round.

The reason is a matter of design. In a metallurgical microscope the objective also acts as the condenser, so the illuminating light passes through the same pupil as the light forming the image. With a continuous ring the whole illumination would pass through the phase coating, which lets only part of the light through and reflects a fair amount of it - and those reflections would swamp the already faint phase contrast image. The solution turned out to be an odd number of segments: the image of the diaphragm formed after reflection off the specimen is rotated by 180 degrees, so with three segments it falls into the gaps between them. The illuminating light therefore enters beside the phase coating and returns through it. The solution is described in patent AT 295883 B.

The objective is offered together with its matching slider (Objektivwechselschlitten) with an M19 thread - and that is no coincidence. The position in which the phase sectors come to rest is decided by how far the objective screws into the thread, and every specimen stops slightly differently, which is why the factory selected objective and slider in pairs and wrote both numbers on the card in the case. Buying such a pair together avoids the whole problem - the objective already sits in relation to its slider exactly as it left the works.

Setting it up in the microscope needs neither a service technician nor a phase telescope - the Neophot has a built-in, swing-out Bertrand lens. The procedure is basically this: switch in the Bertrand lens, focus on the phase sectors and use the adjusting screws to bring the image of the sector diaphragm into coincidence with the image of the sectors in the objective; sometimes a slight rotation of the aperture diaphragm helps as well. Should the position of the glass in the sector diaphragm itself ever need correcting - it is held down by an ordinary threaded ring, so it can be turned. The whole thing resembles centring the phase rings in the condenser of a biological microscope.

Two more things are needed on the microscope side for work in phase contrast: the sector diaphragm (Sektorenblende), pushed in front of the open aperture diaphragm, and the auxiliary lens turret (Hilfslinsenrevolver) on the dovetail of the illuminator. The latter images the diaphragm exactly in the plane of the phase coating, which lies slightly differently in each objective - hence a separate auxiliary lens for every magnification. In bright field the objective of course works perfectly normally.

A note for the DIY-minded: an objective like this can be adapted for transmitted light, except that the diaphragm in the condenser is then set not opposite but in line with the segments of the objective, because there is no second pass through the pupil. Phase contrast should appear, but with stronger halo and a directional relief effect, since the gaps in the ring mean that part of the illumination azimuths is missing. On top of that comes the infinity design with no cover glass correction, so a tube lens will be needed. More of an experiment than a working solution - but doable in one evening.

The last photos in the gallery show:

* a photo of the original table indicating which serial numbers of the objective sliders are factory-paired with which serial numbers of the objectives
* two pages of errata to the instruction manual of the Carl Zeiss Jena Neophot 2 microscope.

The "compatibility" section lists, besides the Carl Zeiss Jena Neophot 21 microscope, those microscopes that this objective fits mechanically and optically. What result you get on them, however, can sometimes be a surprise.

Here (https://www.microscopeparts.eu/part/91056) is the same objective in the version without phase rings. Its description tells you more about using Carl Zeiss Jena objectives with an M19 thread.

Description of this part for the microscope.

21 microscope.

Basic parameters:
Manufacturer: Carl Zeiss Jena
Engraving on the objective: Planachromat 12.5x/0.25 ∞/0 Ph
Magnification: 12.5x
Numerical aperture N.A.: 0.25
Tube length: infinity (more precisely: 250 mm)
Optical correction: planachromatic
Cover glass: no - this objective is intended for work without a cover glass
Immersion: no - this is a so-called dry objective
Phase contrast: yes, a special phase contrast for work in reflected light
Polarisation: no - this is not a polarising objective
Thread: M19
Plan compensating eyepieces: yes, required - this objective needs eyepieces with additional correction (marked "PK" at Carl Zeiss Jena)
Direct projection and macro photography: no - this objective does not work in direct projection mode and is not suitable for macro photography with the objective attached directly to a camera

Phase contrast objectives for the Neophot microscopes have a phase ring built differently from the other Ph objectives made by Carl Zeiss Jena - instead of a continuous ring there is a three-segment pattern, somewhat reminiscent of a Wankel engine rotor. This is worth knowing, because it means that a phase contrast objective from a biological microscope will not replace this one in a Neophot, and the other way round.

The reason is a matter of design. In a metallurgical microscope the objective also acts as the condenser, so the illuminating light passes through the same pupil as the light forming the image. With a continuous ring the whole illumination would pass through the phase coating, which lets only part of the light through and reflects a fair amount of it - and those reflections would swamp the already faint phase contrast image. The solution turned out to be an odd number of segments: the image of the diaphragm formed after reflection off the specimen is rotated by 180 degrees, so with three segments it falls into the gaps between them. The illuminating light therefore enters beside the phase coating and returns through it. The solution is described in patent AT 295883 B.

The objective is offered together with its matching slider (Objektivwechselschlitten) with an M19 thread - and that is no coincidence. The position in which the phase sectors come to rest is decided by how far the objective screws into the thread, and every specimen stops slightly differently, which is why the factory selected objective and slider in pairs and wrote both numbers on the card in the case. Buying such a pair together avoids the whole problem - the objective already sits in relation to its slider exactly as it left the works.

Setting it up in the microscope needs neither a service technician nor a phase telescope - the Neophot has a built-in, swing-out Bertrand lens. The procedure is basically this: switch in the Bertrand lens, focus on the phase sectors and use the adjusting screws to bring the image of the sector diaphragm into coincidence with the image of the sectors in the objective; sometimes a slight rotation of the aperture diaphragm helps as well. Should the position of the glass in the sector diaphragm itself ever need correcting - it is held down by an ordinary threaded ring, so it can be turned. The whole thing resembles centring the phase rings in the condenser of a biological microscope.

Two more things are needed on the microscope side for work in phase contrast: the sector diaphragm (Sektorenblende), pushed in front of the open aperture diaphragm, and the auxiliary lens turret (Hilfslinsenrevolver) on the dovetail of the illuminator. The latter images the diaphragm exactly in the plane of the phase coating, which lies slightly differently in each objective - hence a separate auxiliary lens for every magnification. In bright field the objective of course works perfectly normally.

A note for the DIY-minded: an objective like this can be adapted for transmitted light, except that the diaphragm in the condenser is then set not opposite but in line with the segments of the objective, because there is no second pass through the pupil. Phase contrast should appear, but with stronger halo and a directional relief effect, since the gaps in the ring mean that part of the illumination azimuths is missing. On top of that comes the infinity design with no cover glass correction, so a tube lens will be needed. More of an experiment than a working solution - but doable in one evening.

The last photos in the gallery show:

* a photo of the original table indicating which serial numbers of the objective sliders are factory-paired with which serial numbers of the objectives
* two pages of errata to the instruction manual of the Carl Zeiss Jena Neophot 2 microscope.

The "compatibility" section lists, besides the Carl Zeiss Jena Neophot 21 microscope, those microscopes that this objective fits mechanically and optically. What result you get on them, however, can sometimes be a surprise.

Here (https://www.microscopeparts.eu/part/91056) you can read more about using Carl Zeiss Jena objectives with an M19 thread.

Description of this part for the microscope.

21 microscope.

Basic parameters:
Manufacturer: Carl Zeiss Jena
Engraving on the objective: Planachromat 6.3x/0.12 ∞/0 Ph
Magnification: 6.3x
Numerical aperture N.A.: 0.12
Tube length: infinity (more precisely: 250 mm)
Optical correction: planachromatic
Cover glass: no - this objective is intended for work without a cover glass
Immersion: no - this is a so-called dry objective
Phase contrast: yes, a special phase contrast for work in reflected light
Polarisation: no - this is not a polarising objective
Thread: M19
Plan compensating eyepieces: yes, required - this objective needs eyepieces with additional correction (marked "PK" at Carl Zeiss Jena)
Direct projection and macro photography: no - this objective does not work in direct projection mode and is not suitable for macro photography with the objective attached directly to a camera

Phase contrast objectives for the Neophot microscopes have a phase ring built differently from the other Ph objectives made by Carl Zeiss Jena - instead of a continuous ring there is a three-segment pattern, somewhat reminiscent of a Wankel engine rotor. This is worth knowing, because it means that a phase contrast objective from a biological microscope will not replace this one in a Neophot, and the other way round.

The reason is a matter of design. In a metallurgical microscope the objective also acts as the condenser, so the illuminating light passes through the same pupil as the light forming the image. With a continuous ring the whole illumination would pass through the phase coating, which lets only part of the light through and reflects a fair amount of it - and those reflections would swamp the already faint phase contrast image. The solution turned out to be an odd number of segments: the image of the diaphragm formed after reflection off the specimen is rotated by 180 degrees, so with three segments it falls into the gaps between them. The illuminating light therefore enters beside the phase coating and returns through it. The solution is described in patent AT 295883 B.

The objective is offered together with its matching slider (Objektivwechselschlitten) with an M19 thread - and that is no coincidence. The position in which the phase sectors come to rest is decided by how far the objective screws into the thread, and every specimen stops slightly differently, which is why the factory selected objective and slider in pairs and wrote both numbers on the card in the case. Buying such a pair together avoids the whole problem - the objective already sits in relation to its slider exactly as it left the works.

Setting it up in the microscope needs neither a service technician nor a phase telescope - the Neophot has a built-in, swing-out Bertrand lens. The procedure is basically this: switch in the Bertrand lens, focus on the phase sectors and use the adjusting screws to bring the image of the sector diaphragm into coincidence with the image of the sectors in the objective; sometimes a slight rotation of the aperture diaphragm helps as well. Should the position of the glass in the sector diaphragm itself ever need correcting - it is held down by an ordinary threaded ring, so it can be turned. The whole thing resembles centring the phase rings in the condenser of a biological microscope.

Two more things are needed on the microscope side for work in phase contrast: the sector diaphragm (Sektorenblende), pushed in front of the open aperture diaphragm, and the auxiliary lens turret (Hilfslinsenrevolver) on the dovetail of the illuminator. The latter images the diaphragm exactly in the plane of the phase coating, which lies slightly differently in each objective - hence a separate auxiliary lens for every magnification. In bright field the objective of course works perfectly normally.

A note for the DIY-minded: an objective like this can be adapted for transmitted light, except that the diaphragm in the condenser is then set not opposite but in line with the segments of the objective, because there is no second pass through the pupil. Phase contrast should appear, but with stronger halo and a directional relief effect, since the gaps in the ring mean that part of the illumination azimuths is missing. On top of that comes the infinity design with no cover glass correction, so a tube lens will be needed. More of an experiment than a working solution - but doable in one evening.

The last photos in the gallery show:

* a photo of the original table indicating which serial numbers of the objective sliders are factory-paired with which serial numbers of the objectives
* two pages of errata to the instruction manual of the Carl Zeiss Jena Neophot 2 microscope.

The "compatibility" section lists, besides the Carl Zeiss Jena Neophot 21 microscope, those microscopes that this objective fits mechanically and optically. What result you get on them, however, can sometimes be a surprise.

Here (https://www.microscopeparts.eu/part/91056) you can read more about using Carl Zeiss Jena objectives with an M19 thread.

Description of this part for the microscope.

camera to a trinocular head or directly to the microscope stand, even when there is no trinocular head at all.

This is a black tube with an upper element (barrel) 55 mm long. Here (https://www.microscopeparts.eu/gallery/91057) you can see a functionally identical adapter, but grey and with an upper barrel only 25 mm long.

Black adapters of this kind come from the era of the Carl Zeiss Jena L stands (models Carl Zeiss Jena Lg, Lumipan, Ng, Nf or Nu). The grey ones are newer, from the era of the Mikroval series (models Carl Zeiss Jena Laboval, Eduval, Ergaval or Amplival and Docuval).

The mounting fit is of course identical, so both can be used interchangeably.

Basic technical parameters of this tube:
Manufacturer: Carl Zeiss Jena
Colour: black
Inclination angle: none, this is a straight tube
Internal optics: none - not even a deflecting prism
Mounting to a trinocular head or microscope stand: ring dovetail
Ring dovetail diameter: 41.5 mm
Type of connection at the output: empty barrel / tube
Tube diameter at the output: 23.2 mm inner diameter
Barrel / tube length: 55 mm
Tube length adjustment: no - this is not a height-adjustable tube

Because on the output side this adapter has an empty barrel with an inner diameter of 23.2 mm, you can place in it a projection eyepiece of that diameter or a so-called USB eyepiece, that is a digital microscope camera. In addition, adapters between the 23.2 mm barrel and the M42 thread are widely available, and from the M42 thread you can already move on to any other mount: Nikon, Canon, Sony and all the rest.

Such a tube can be mounted directly on the microscope stand, in place of the head. A seat for a ring dovetail of 41.0 - 41.5 mm diameter is found among others in the microscopes:
- Carl Zeiss Jena
- LOMO
- Meopta
- IOR
- Reichert Biopan
- Olympus CH
- Gamma

It is also used in microscopes with a slightly larger seat, among others Zeiss West Germany, Leitz Wetzlar, PZO, Will Wetzlar, Hund Wetzlar.

The adapter can likewise be fitted onto trinocular heads, as many of them have a seat prepared for it, among others:
- the output in the trinocular tubes of the microscopes Carl Zeiss Jena Jenamed, Jenaval, Jenalumar, Jenatech, Jenavert, Jenapol
- the LOMO TRN-1 heads (ЛОМО ТРН-1), found in LOMO Polam microscopes
- some versions of the black intermediate photo tubes for the microscopes Carl Zeiss Jena Lg / Lumipan / Nf and of the grey ones from the Mikroval series (others require a tube that screws in on a thread)

This is not a tube for one particular microscope model. A trinocular head can be mounted not only on the microscope it was sold with, so the correct assumption is that this is a universal tube with a ring dovetail of 41.5 mm diameter on one side and a barrel of 23.2 mm diameter on the other.

In the compatibility section you will find an example list of microscopes this tube fits, although that list is not complete.

Description of this part for the microscope.

Jena
Inscription: logo "Carl Zeiss Jena" and text "Q1 MADE IN DDR"
Material: aluminium
Length: 52 mm
Width: 14 mm
Mounting: the nameplate is glued on

By default such a nameplate was fitted to most Carl Zeiss Jena microscopes from the Mikroval series onwards. There is also a smaller nameplate - with the manufacturer logo only (without the "Q1 Made in DDR" text). You can see it here: https://www.microscopeparts.eu/part/00604.

Because the adhesive used to attach these plates to the microscope body loses its properties over the years, these plates very often fall off. A nameplate like this makes it possible to restore the factory appearance of a microscope using original parts.