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.

Basic parameters of this objective:
Manufacturer: Lomo, Russia (ЛОМО)
Magnification: 90x
Marking on the objective: МИ 90 1.25 (MI 90 1.25)
Numerical aperture N.A.: 1.25
Serial number: starts with "74"
Year of manufacture: 1974
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: yes, 0.17 mm thick
Immersion: yes, oil
Translation: "МИ" stands for "масляная иммерсия", i.e. "oil immersion"
Specimen protection: yes, the objective has a spring-loaded front mount that prevents breaking the slide
Thread: RMS

Why do I state the year of manufacture in the description of this objective? Older LOMO microscope parts (objectives, microscopes, heads) have the year of manufacture encoded in the serial number: the first two digits of the serial number are the year. Many users want to complete their microscope with parts made in the same year as the microscope itself.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

Fun fact: LOMO made adapters between the RMS and M27 threads. Thanks to them, this objective was fitted to the Lomo Biolam I and Lomo Biolam M microscopes. Owners of Carl Zeiss Axio series microscopes with M27 thread also took advantage of this and used these adapters.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

Basic parameters of this objective:
Manufacturer: Lomo, Russia (ЛОМО)
Magnification: 90x
Marking on the objective: МИ 90 1.25 (MI 90 1.25)
Numerical aperture N.A.: 1.25
Serial number: starts with "73"
Year of manufacture: 1973
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: yes, 0.17 mm thick
Immersion: yes, oil
Translation: "МИ" stands for "масляная иммерсия", i.e. "oil immersion"
Specimen protection: yes, the objective has a spring-loaded front mount that prevents breaking the slide
Thread: RMS

Why do I state the year of manufacture in the description of this objective? Older LOMO microscope parts (objectives, microscopes, heads) have the year of manufacture encoded in the serial number: the first two digits of the serial number are the year. Many users want to complete their microscope with parts made in the same year as the microscope itself.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

Fun fact: LOMO made adapters between the RMS and M27 threads. Thanks to them, this objective was fitted to the Lomo Biolam I and Lomo Biolam M microscopes. Owners of Carl Zeiss Axio series microscopes with M27 thread also took advantage of this and used these adapters.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

objective (model 8 0.20) is frequently used for macro photography with a microscope or a camera (via an RMS adapter or a bellows). Although it is an achromat, it renders fine detail very sharply and performs well in focus stacking. It complements a set together with the LOMO 3.7x, Carl Zeiss Jena Semiplan 6.3x and Nikon M Plan 10x.

Basic parameters of this objective:
Manufacturer: Lomo, USSR (ЛОМО)
Magnification: 8x
Correction: achromatic
Marking on the objective: 8 0.20
Numerical aperture N.A.: 0.20
Serial number: starts with "72"
Year of manufacture: 1972
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: not critical - objectives with such low magnification work both with and without a cover glass
Immersion: no (dry objective)
Thread: RMS

Important - this objective is suitable for direct projection photography, as it does not require plan-compensating optics.

A microscope objective with such low magnification (with a 160 mm tube length it gives an 8:1 reproduction ratio) is used, among other things, for observing or photographing:
- insects
- minerals
- inclusions in amber
- handwriting
- micro shells (micromollusks)
- and much more

Why do I state the year of manufacture in the description of this objective? Older LOMO microscope parts (objectives, microscopes, heads) have the year of manufacture encoded in the serial number: the first two digits of the serial number are the year. Many users want to complete their microscope with parts made in the same year as the microscope itself.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

Fun fact: LOMO made adapters between the RMS and M27 threads. Thanks to them, this objective was fitted to the Lomo Biolam I and Lomo Biolam M microscopes. Owners of Carl Zeiss Axio series microscopes with M27 thread also took advantage of this and used these adapters.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

objective (model 8 0.20) is frequently used for macro photography with a microscope or a camera (via an RMS adapter or a bellows). Although it is an achromat, it renders fine detail very sharply and performs well in focus stacking. It complements a set together with the LOMO 3.7x, Carl Zeiss Jena Semiplan 6.3x and Nikon M Plan 10x.

Basic parameters of this objective:
Manufacturer: Lomo, USSR (ЛОМО)
Magnification: 8x
Correction: achromatic
Marking on the objective: 8 0.20
Numerical aperture N.A.: 0.20
Serial number: starts with "86"
Year of manufacture: 1986
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: not critical - objectives with such low magnification work both with and without a cover glass
Immersion: no (dry objective)
Thread: RMS

Important - this objective is suitable for direct projection photography, as it does not require plan-compensating optics.

A microscope objective with such low magnification (with a 160 mm tube length it gives an 8:1 reproduction ratio) is used, among other things, for observing or photographing:
- insects
- minerals
- inclusions in amber
- handwriting
- micro shells (micromollusks)
- and much more

Why do I state the year of manufacture in the description of this objective? Older LOMO microscope parts (objectives, microscopes, heads) have the year of manufacture encoded in the serial number: the first two digits of the serial number are the year. Many users want to complete their microscope with parts made in the same year as the microscope itself.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

Fun fact: LOMO made adapters between the RMS and M27 threads. Thanks to them, this objective was fitted to the Lomo Biolam I and Lomo Biolam M microscopes. Owners of Carl Zeiss Axio series microscopes with M27 thread also took advantage of this and used these adapters.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

20) is frequently used for macro photography with a microscope or a camera (via an RMS adapter or a bellows). Although it is an achromat, it renders fine detail very sharply and performs well in focus stacking. It complements a set together with the LOMO 3.7x, Carl Zeiss Jena Semiplan 6.3x and Nikon M Plan 10x.

Basic parameters of this objective:
Manufacturer: Lomo, Russia (ЛОМО)
Magnification: 8x
Correction: achromatic
Marking on the objective: 8 0.20
Numerical aperture N.A.: 0.20
Serial number: starts with "92"
Year of manufacture: 1992
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: not critical - objectives with such low magnification work both with and without a cover glass
Immersion: no (dry objective)
Thread: RMS

Important - this objective is suitable for direct projection photography, as it does not require plan-compensating optics.

A microscope objective with such low magnification (with a 160 mm tube length it gives an 8:1 reproduction ratio) is used, among other things, for observing or photographing:
- insects
- minerals
- inclusions in amber
- handwriting
- micro shells (micromollusks)
- and much more

Why do I state the year of manufacture in the description of this objective? Older LOMO microscope parts (objectives, microscopes, heads) have the year of manufacture encoded in the serial number: the first two digits of the serial number are the year. Many users want to complete their microscope with parts made in the same year as the microscope itself.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

Fun fact: LOMO made adapters between the RMS and M27 threads. Thanks to them, this objective was fitted to the Lomo Biolam I and Lomo Biolam M microscopes. Owners of Carl Zeiss Axio series microscopes with M27 thread also took advantage of this and used these adapters.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

Lomo, USSR (ЛОМО)
Magnification: 8x
Correction: achromatic
Marking on the objective: 8 0.20
Numerical aperture N.A.: 0.20
Serial number: starts with "66"
Year of manufacture: 1966
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: not critical - objectives with such low magnification work both with and without a cover glass
Immersion: no (dry objective)
Thread: RMS

The LOMO 8x objective (model 8 0.20) is frequently used for macro photography with a microscope or a camera (via an RMS adapter or a bellows). Although it is an achromat, it renders fine detail very sharply and performs well in focus stacking. It complements a set together with the LOMO 3.7x, Carl Zeiss Jena Semiplan 6.3x and Nikon M Plan 10x.

Important - this objective is suitable for direct projection photography, as it does not require plan-compensating optics.

A microscope objective with such low magnification (with a 160 mm tube length it gives an 8:1 reproduction ratio) is used, among other things, for observing or photographing:
- insects
- minerals
- inclusions in amber
- handwriting
- micro shells (micromollusks)
- and much more

Why do I state the year of manufacture in the description of this objective? Older LOMO microscope parts (objectives, microscopes, heads) have the year of manufacture encoded in the serial number: the first two digits of the serial number are the year. Many users want to complete their microscope with parts made in the same year as the microscope itself.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

Fun fact: LOMO made adapters between the RMS and M27 threads. Thanks to them, this objective was fitted to the Lomo Biolam I and Lomo Biolam M microscopes. Owners of Carl Zeiss Axio series microscopes with M27 thread also took advantage of this and used these adapters.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

(ЛОМО)
Version: this is the OEM version of this objective; it was made for export and has no engraved manufacturer logo
Magnification: 90x
Correction: achromatic
Marking on the objective: A 90*1.25
Numerical aperture N.A.: 1.25
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: yes, 0.17 mm thick
Immersion: yes, oil
Specimen protection: yes, the objective has a spring-loaded front mount that prevents breaking the slide
Thread: RMS

LOMO exported its microscopes to Western Europe, where they were sold under the names Bresser Biolam / Bresser Erudit (mainly in Germany) and Zenith Biolam (in the UK). These microscopes often (but not always) came with special versions of the objectives without the "ЛОМО" engraving.

Apart from the missing manufacturer name, the export version also differs in the way the parameters are marked. On the LOMO version the marking read "МИ 90 1.25", where "МИ" is an abbreviation written in Cyrillic, corresponding to "MI" and meaning "oil immersion". The export version dropped the Cyrillic (and even the immersion information), and the marking changed to "A 90*1.25".

A note on the Bresser Erudit microscope: Bresser sold two different microscopes under this name. The first was a Lomo microscope labelled "Bresser Erudit", the second is the plastic, Chinese-made "Bresser Erudit DLX" microscope.
The microscope objective offered here fits the first of these two Erudit microscopes. A photo gallery of the first model can be found here: https://www.microscopeparts.eu/gallery/lomo-erudit-microscopes-207.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

20x
Correction: Fluotar (other names: Fluor and fluorite)
Numerical aperture N.A.: 0.60
Tube length: 160 mm
Parfocal length: 33 mm
Cover glass: yes, 0.17 mm thick
Immersion: no (dry objective)
Thread: RMS

The objective comes in its original protective case marked "Wild Heerbrugg Switzerland".

Fluotar is the name Wild Heerbrugg used for its fluorite objectives, i.e. semi-apochromats - their lenses contain fluorite or glass with similar optical properties. A standard achromat corrects chromatic errors for only two colors (red and blue), so colored fringes may appear along the edges of objects. An apochromat corrects for three colors (red, green and blue) and represents the highest class of correction. The Fluotar sits between them - colored fringes are clearly smaller than with an achromat, although the correction is not as complete as with an apochromat. Fluorite also transmits ultraviolet light well, which is why objectives of this type were used in fluorescence microscopy.

This is a so-called "short barrel" objective with a parfocal length of 33 mm. It is very common to mount this objective on a 12 mm extension, which allows it to be used in microscopes that require 45 mm parfocal objectives. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well for this.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL=160 mm and a parfocal length of 33 mm (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

microscope or a camera (via an RMS adapter or a bellows). Although it is an achromat, it renders fine detail very sharply and performs well in focus stacking. It complements a set together with the LOMO 3.7x, Carl Zeiss Jena Semiplan 6.3x and Nikon M Plan 10x.

Basic parameters of this objective:
Manufacturer: Lomo, Russia (ЛОМО)
Magnification: 8x
Correction: achromatic
Marking on the objective: 8 0.20
Numerical aperture N.A.: 0.20
Serial number: starts with "91"
Year of manufacture: 1991
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: not critical - objectives with such low magnification work both with and without a cover glass
Immersion: no (dry objective)
Thread: RMS

Important - this objective is suitable for direct projection photography, as it does not require plan-compensating optics.

A microscope objective with such low magnification (with a 160 mm tube length it gives an 8:1 reproduction ratio) is used, among other things, for observing or photographing:
- insects
- minerals
- inclusions in amber
- handwriting
- micro shells (micromollusks)
- and much more

Why do I state the year of manufacture in the description of this objective? Older LOMO microscope parts (objectives, microscopes, heads) have the year of manufacture encoded in the serial number: the first two digits of the serial number are the year. Many users want to complete their microscope with parts made in the same year as the microscope itself.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

Fun fact: LOMO made adapters between the RMS and M27 threads. Thanks to them, this objective was fitted to the Lomo Biolam I and Lomo Biolam M microscopes. Owners of Carl Zeiss Axio series microscopes with M27 thread also took advantage of this and used these adapters.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

Description of this part for the microscope.

of view number: 12
Mounting diameter: 23.2 mm
Designation: PK = plan compensating - recommended for work with planachromatic objectives, but they also work without any trouble with achromats or apochromats

Because of their very high quality they are often used on microscopes from other manufacturers as well, especially when Carl Zeiss Jena Planachromat objectives are mounted in them. The "compatibility" section lists a long series of microscopes these eyepieces fit - but that list is definitely not complete.

Important: these eyepieces work both on microscopes with a finite tube length (160 mm, for example) and on microscopes with infinity optics. That means you can use them on the Carl Zeiss Jena Amplival microscope just as well as on the Carl Zeiss Jena NU-2 microscope.

A note - eyepieces with such a strong magnification are in my opinion better suited to a quick look than to permanent work. I write "in my opinion" on purpose, because this comes from using them and not from the manufacturer's description.
A 16x eyepiece magnification should be treated as a zoom that brings out no additional detail (the resolution is not increased). This matters for example with heads that have their own extra magnification (such as Carl Zeiss Jena heads with a built-in 1.5x or 1.6x factor) - working with a 100x oil immersion objective you then theoretically get 100*1.5*16 = 2400x, while physics does not allow light from the visible range to be usefully magnified for the human eye beyond roughly 1250x - so this is what is called empty magnification.

Description of this part for the microscope.

5x
Field of view number: 16
Mounting diameter: 23.2 mm
Designation: PK = plan compensating - recommended for work with planachromatic objectives, but they also work without any trouble with achromats or apochromats

Because of their very high quality they are often used on microscopes from other manufacturers as well, especially when Carl Zeiss Jena Planachromat objectives are mounted in them. The "compatibility" section lists a long series of microscopes these eyepieces fit - but that list is definitely not complete.

Important: these eyepieces work both on microscopes with a finite tube length (160 mm, for example) and on microscopes with infinity optics. That means you can use them on the Carl Zeiss Jena Amplival microscope just as well as on the Carl Zeiss Jena NU-2 microscope.

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.

the OEM version of this objective; it was made for export and has no engraved manufacturer logo
Magnification: 40x
Correction: achromatic
Marking on the objective: 40 0,65
Numerical aperture N.A.: 0,65
Tube length: 160 mm
Parfocal length: 33 mm - so-called short barrel objective
Cover glass: yes, 0.17 mm thick
Immersion: no
Specimen protection: yes, the objective has a spring-loaded front mount that prevents breaking the slide
Thread: RMS

LOMO exported its microscopes to Western Europe, where they were sold under the names Bresser Biolam / Bresser Erudit (mainly in Germany) and Zenith Biolam (in the UK). These microscopes often (but not always) came with special versions of the objectives without the "ЛОМО" engraving.

A note on the Bresser Erudit microscope: Bresser sold two different microscopes under this name. The first was a Lomo microscope labelled "Bresser Erudit", the second is the plastic, Chinese-made "Bresser Erudit DLX" microscope.
The microscope objective offered here fits the first of these two Erudit microscopes. A photo gallery of the first model can be found here: https://www.microscopeparts.eu/gallery/lomo-erudit-microscopes-207.

This is a so-called short barrel objective with a parfocal length of 33 mm. It is very often mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives with a 45 mm parfocal length. Professional adapters with protective optics, metal adapters and popular DIY 3D-printed adapters all work well here.

LOMO objectives are very popular with owners of microscopes from other manufacturers. Due to historical ties, owners of Carl Zeiss Jena microscopes regard them as an obvious replacement for the German objectives.

This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL = 160 mm and 33 mm parfocal length (or 37 / 45 mm with a suitable adapter). Several example microscopes are listed in the "compatibility" section, but the list is not complete.

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.

objective:
Manufacturer: Lomo (ЛОМО)
Magnification: 40x
Correction: achromatic
Engraving on the objective: 40 0,65 Ф-2 ЛОМО
Numerical aperture N.A.: 0,65
Working distance: 0,55 mm
Tube length: 160 mm
Parfocal length: 33 mm - a so-called short barrel objective
Cover glass: yes, 0,17 mm thick
Phase contrast: yes, type F-2 (Ф-2), which means there are two phase rings inside the objective
Immersion: no (dry objective, sometimes called an "air immersion" objective)
Specimen protection: no, the objective has no spring-loaded mechanism
Thread: RMS
Work in brightfield without phase contrast: possible, but even the manufacturer states in the manual that the image quality is worse than with an objective without phase rings inside

A very important note: two phase rings inside an objective bring to mind variable phase contrast (PhZ at PZO or PhV at Carl Zeiss Jena). With LOMO, however, this is rather something like a "second type of positive phase contrast". LOMO states in the manual (https://laboratorium.dp.ua/item/68) that one image is obtained when light passes through both rings (with the condenser iris diaphragm open) - and a different one when the diaphragm is closed far enough that light no longer reaches the outer, wide ring and only the inner ring works. The manufacturer recommends viewing the specimen in both modes, because together they give a more reliable idea of its structure. The contrast stays positive (thicker or denser parts of the specimen appear darker against a bright background), and both modes differ from work with the single-ring "Ф" objectives and the LOMO KF-4 condenser (ЛОМО KФ-4), where both the objective and the condenser diaphragm have only one ring. So the resulting effect does change - but this is not variable phase contrast; the change is stepwise (either-or), not continuous.

The objective presented here fits the LOMO KF-5 condenser (ЛОМО KФ-5). That condenser has a mounting diameter of 37 mm and is very often used on microscopes from other makers, among them Carl Zeiss Jena and Olympus (especially Olympus CH). With a suitable build-up ring fitted (3D printed, for example), this condenser is commonly used in microscopes with a 39,5 mm condenser seat as well. The instructions for setting up LOMO KF-5 phase contrast can be found here: https://scopica.ru/proj/ustroystvo-dlya-nablyudeniya-metodom-fazovogo-kontrasta-kf-5/

This is a so-called short barrel objective, with a parfocal length of 33 mm. It is very commonly mounted on a 12 mm extension, which allows it to be used in microscopes that require objectives of 45 mm length. Professional adapters with protective optics, metal adapters and the popular 3D printed DIY solutions all work here.

LOMO objectives are very popular with owners of microscopes from other makers. Because of the historical links, owners of Carl Zeiss Jena microscopes treat them as an obvious substitute for those German objectives.

This objective fits practically any microscope from any maker, provided it has an RMS thread and accepts objectives with TL=160 mm and a parfocal length of 33 mm (or 37 / 45 mm if a suitable adapter is used). A few such microscopes are listed in the "compatibility" section, but that is not a complete list.

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.

10x
Mounting diameter: 23.2 mm

Because this is important, I will write it again: this is a single eyepiece, not a pair of eyepieces.

This is a solution for people who:
- either have a pair of these eyepieces, but one of them needs to be replaced
- or have a microscope with a monocular head

For Will Wetzlar microscopes, eyepieces from practically any manufacturer can be used, provided that they are designed for a finite tube length system and have a mounting diameter of 23.2 mm. However, many users appreciate having original parts.

This eyepiece also works the other way around - it fits almost any microscope from any manufacturer that allows the use of eyepieces with a mounting diameter of 23.2 mm. Users of microscopes from many manufacturers are happy to choose German eyepieces because of their high quality. I have included some examples in the "compatibility" section, but this is definitely not a complete list.

Microscope users have several names for eyepieces of this type with a large field of view. Among others:
- wide field eyepiece
- widefield ocular
- WF eyepiece
- wide angle eyepiece
- large field of view eyepiece

Description of this part for the microscope.

catalogue number: 46 78 36 (also written as 467836)
Colour: blue matt
Diameter: 32 mm
Material: glass

This is a filter that combines the functions of a blue filter and a ground glass diffuser:
- the blue filter is used to convert the yellow, warm light of the bulb into light closer to white light
- the matt filter (called a diffuser or ground glass) is used to even out the light across the whole area of the specimen and to remove the visible filament of the bulb

This does, however, have one consequence: without a visible filament it is not possible to work with illumination set up according to the Koehler method - and Zeiss mentions this in the leaflet supplied with the filter.

Very often only one or two microscope filters can be fitted in a microscope, for example one on the illuminator and the second in the holder below the condenser. The fact that the glass filter offered here is a 2-in-1 solution makes it possible to save the possible second slot for another filter.

The diameter of 32 mm is a standard with many manufacturers, which means this filter can be used with microscopes of numerous brands. The "compatibility" section lists over a dozen such microscopes, but it is not a complete list.

Description of this part for the microscope.

Jena microscopes over nearly 100 years. They differ in the appearance of the barrel and in the engraving.

Appearance of this variant of the Carl Zeiss Jena 8x objective:
- black section next to the thread
- silver upper section
- the marking "8/0,20 160/-" on one side of the silver part of the barrel
- the Carl Zeiss Jena logo and the serial number on the other side of the silver barrel

Here (https://www.microscopeparts.eu/part/99852) you will see the same Carl Zeiss Jena 8x objective, but in a slightly older variant (without the value "160/-" engraved on the barrel).

The Carl Zeiss Jena 8x objective is often used for macro photography - both on a microscope and on a camera (with an RMS adapter or a bellows unit). Although it is an achromatic objective, it renders fine detail very well and works nicely for focus stacking. It is a good complement to a set together with the Carl Zeiss Jena Semiplan 3.2x, LOMO 3.7x, Carl Zeiss Jena Semiplan 6.3x and Nikon M Plan 10x objectives.

Basic parameters of this objective:
Manufacturer: Carl Zeiss Jena
Magnification: 8x
Correction: achromatic
Marking on the objective: 8/0,20 160/-
Numerical aperture N.A.: 0.20
Serial number: above 580 000
Tube length: 160 mm
Parfocal length: 33 mm - a so-called short barrel objective
Cover glass: either way - objectives with such a low magnification can work both with and without a cover glass
Immersion: no (a so-called dry objective)
Thread: RMS

Important - this objective is suitable for taking pictures with the "direct-projection" technique, because it does not require plan-compensating optics.

A microscope objective with such a low magnification (keeping the 160 mm tube we get an 8:1 reproduction ratio) is used for observation or macro photography of, among other things:
- insects
- minerals
- inclusions in amber
- handwriting
- micro shells

Why do I describe the appearance of this variant so precisely in the description of this objective? Some users care about completing their Carl Zeiss Jena microscope with parts from the same series and roughly from the same period. The exact way the parameters are written on the barrel makes it possible to compare this objective not only from the photos in the gallery, but also at the level of the text description - especially for AI systems.

This is a so-called "short barrel objective", with a parfocal length of 33 mm. Very often this objective is mounted on a 12 mm extension, which makes it possible to use it in microscopes that require objectives with a parfocal length of 45 mm. Professional adapters with corrective optics work well here, as do plain metal adapters and the popular DIY parts from a 3D printer.

This objective fits practically any microscope from any manufacturer, provided it has an RMS thread and supports objectives with TL=160 mm and a parfocal length of 33 mm (or 37 / 45 mm if we use a suitable adapter). A few examples of such microscopes are listed in the "compatibility" section, but that is not a complete list.

Carl Zeiss Jena objectives are very popular among users of microscopes from other manufacturers. Because of the historical connections, owners of LOMO microscopes treat them as an obvious replacement for their own Soviet optics.

After the Second World War the Carl Zeiss Jena production plant ended up in the Soviet occupation zone, and the Russians began copying the German technical documentation - see for yourself that the LOMO 8x objectives are an exact copy of the objective presented here: https://www.microscopeparts.eu/?search_2=8x&search_7=ob&search_8=lomo. The objectives made for school microscopes such as the Opta Junat are also a clone of Carl Zeiss Jena optics: https://www.microscopeparts.eu/part/00639.

Description of this part for the microscope.

Jena microscopes over nearly 100 years. They differ in the appearance of the barrel and in the engraving.

Appearance of this variant of the Carl Zeiss Jena 8x objective:
- black section next to the thread
- silver upper section
- the digit "8" on the first line and "0,20" on the second line, on one side of the silver part of the barrel
- the Carl Zeiss Jena logo and the serial number on the other side of the silver barrel

Here (https://www.microscopeparts.eu/part/99851) you will see the same Carl Zeiss Jena 8x objective, but in a slightly newer variant (with the value "160/-" engraved on the barrel).

The Carl Zeiss Jena 8x objective is often used for macro photography - both on a microscope and on a camera (with an RMS adapter or a bellows unit). Although it is an achromatic objective, it renders fine detail very well and works nicely for focus stacking. It is a good complement to a set together with the Carl Zeiss Jena Semiplan 3.2x, LOMO 3.7x, Carl Zeiss Jena Semiplan 6.3x and Nikon M Plan 10x objectives.

Basic parameters of this objective:
Manufacturer: Carl Zeiss Jena
Magnification: 8x
Correction: achromatic
Marking on the objective: 8 0,20
Numerical aperture N.A.: 0.20
Serial number: 503 729
Tube length: 160 mm
Parfocal length: 33 mm - a so-called short barrel objective
Cover glass: either way - objectives with such a low magnification can work both with and without a cover glass
Immersion: no (a so-called dry objective)
Thread: RMS

Important - this objective is suitable for taking pictures with the "direct-projection" technique, because it does not require plan-compensating optics.

A microscope objective with such a low magnification (keeping the 160 mm tube we get an 8:1 reproduction ratio) is used for observation or macro photography of, among other things:
- insects
- minerals
- inclusions in amber
- handwriting
- micro shells

Why do I describe the appearance of this variant so precisely in the description of this objective? Some users care about completing their Carl Zeiss Jena microscope with parts from the same series and roughly from the same period. The exact way the parameters are written on the barrel makes it possible to compare this objective not only from the photos in the gallery, but also at the level of the text description - especially for AI systems.

This is a so-called "short barrel objective", with a parfocal length of 33 mm. Very often this objective is mounted on a 12 mm extension, which makes it possible to use it in microscopes that require objectives with a parfocal length of 45 mm. Professional adapters with corrective optics work well here, as do plain metal adapters and the popular DIY parts from a 3D printer.

This objective fits practically any microscope from any manufacturer, provided it has an RMS thread and supports objectives with TL=160 mm and a parfocal length of 33 mm (or 37 / 45 mm if we use a suitable adapter). A few examples of such microscopes are listed in the "compatibility" section, but that is not a complete list.

Carl Zeiss Jena objectives are very popular among users of microscopes from other manufacturers. Because of the historical connections, owners of LOMO microscopes treat them as an obvious replacement for their own Soviet optics.

After the Second World War the Carl Zeiss Jena production plant ended up in the Soviet occupation zone, and the Russians began copying the German technical documentation - see for yourself that the LOMO 8x objectives are an exact copy of the objective presented here: https://www.microscopeparts.eu/?search_2=8x&search_7=ob&search_8=lomo. The objectives made for school microscopes such as the Opta Junat are also a clone of Carl Zeiss Jena optics: https://www.microscopeparts.eu/part/00639.

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.

5x
Magnification: 2.5x
Mounting diameter: 23.2 mm

Please note: this is a "CF" projection photo eyepiece, meaning "Chrome Free" (chromatic aberration free). The eyepiece itself carries no chromatic correction - for correct results it has to sit in the microscope objective. In the case of Nikon, those are the CF (CFN) and CFI objectives.

The standard 23.2 mm mounting diameter allows it to be used in the projection tubes of many microscopes from various manufacturers - both biological and stereo ones.

It has to be said that this is a very universal projection eyepiece. In the "compatibility" section I list only a small part of the microscopes this photo eyepiece can be used with.

From the experience of people I know, only testing a projection eyepiece yourself on a specific microscope setup gives you certainty about how it will behave.

With every configuration - different objectives, a different tube length, a different photo adapter, camera, DSLR, sensor size - the user will get a different result.

This applies to tests both on microscopes with finite tube length optics (for example the Nikon Labophot with 160 mm optics) and infinity optics (for example the Nikon Eclipse E600 infinity), and both on older stereo microscopes (for example the Nikon SMZ-10) and somewhat newer ones such as the Nikon SMZ-1500.

Description of this part for the microscope.

5
Magnification: 5x
Field number F.N.: 25
Mounting diameter: 23.2 mm

Please note: PLI is a series of projection eyepieces assigned to the CFI60 system (optics corrected for infinity / "I" as in "infinity"). I have, however, personally seen eyepieces from this series used on microscopes with optics corrected for a finite tube length (160 mm, to be precise).

This eyepiece contains no chromatic correction lenses, so that correction has to be built into the objective (in the case of Nikon objectives these are the CF / CFN / CFI series).

The standard 23.2 mm mounting diameter allows it to be used in the projection tubes of many microscopes from various manufacturers - both biological and stereo ones. It therefore has to be regarded as a very universal projection eyepiece. In the "compatibility" section I list only a small part of the microscopes this photo eyepiece can be used with.

From the experience of people I know, only testing a projection eyepiece yourself on a specific microscope setup gives you certainty about how it will behave.

With every configuration - different objectives, a different tube length, a different photo adapter, camera, DSLR, sensor size - the user will get a different result.

This applies to tests both on microscopes with finite tube length optics (for example the Nikon Alphaphot with 160 mm optics) and infinity optics (for example the Nikon Eclipse TS-100 infinity), and both on older stereo microscopes (for example the Nikon SMZ-2T) and somewhat newer ones such as the Nikon SMZ-18.