Microscope marking objective

[old martParticipant @oldmart]

I have just bought a small job lot of microscope related bits on ebay and this unusual objective was amongst them.

Made by Carl Zeiss of Jena, it is marked OBEKTMARKIERER  PLANOBJEKTIVE TUBUS with an infinity symbol. The tip looks like carbide and is not dead sharp, but has a tiny radius, and it can be offset from central to about 4mm diameter, calibrated in 0.25mm steps. The whole lower part can rotate and has a rest position and cams downward about 0.5mm when turned. A specialised tool for marking metal surfaces with a ring, it is not sharp enough to mark glass without breaking it

[Roderick JenkinsParticipant @roderickjenkins93242]

Interesting!

[Michael GilliganParticipant @michaelgilligan61133]

VERY nice !

… I have a Nikon one, but it uses ink and is nowhere near in that league.

MichaelG.

[old martParticipant @oldmart]

I’ve no idea what I would do with it, the first photo shows a thin red ring showing when the tip is extended for marking.

[Michael GilliganParticipant @michaelgilligan61133]

I have just found its twin listed here:

https://www.ebay.de/itm/284579952041

 

MichaelG.

[old martParticipant @oldmart]

I hardly think it is worth a fraction of 130 euros, the market will be tiny.

[peak4Participant @peak4]

I wonder if it should be sharp, and has been rounded by misuse/wear, or is a blank awaiting sharpening?
Here’s an example with a diamond point, intended for marking cover slips on slides, so the observer can find something of interest again later.
https://microscope-antiques.com/watsonom.html

Bill

 

[old martParticipant @oldmart]

That Watson with the diamond point is spring loaded, the CZ is not, and would be hazardous if a brittle surface was touched. I will have a look at the tip at about 20-50X and report on the exact profile.

[old martParticipant @oldmart]

Having considered why the CZ tip was fixed and the watson sprung, I pressed the objective against a block of wood, and at about 1Kg force, the tip moved in. I have dismantled the tip and cleaned it andwith a spot of light oil, it is moving as designed. The tip profile is a tiny radius which shows no sign of damage. The tip has a movement of about 2mm with a spring force of about 50 grammes.

 

 

 

 

 

 

 

[old martParticipant @oldmart]

Having forgotten all about it for some time, it turned up in a box of objectives and I tried it out on a blank slide. It is very difficult to see exactly how far to touch on considering that the end extends when it is turned. Also, it is hard to get banana fingers to turn it with the other objectives in the turret. I did get 2mm and 4mm circles cut in the slide, but no photos even with a 2X objective, the CCD mini camera only shows part of the circle and it is indistinct, and I can’t find the adaptor for my Pentax K5D with it’s much larger sensor.

[Michael GilliganParticipant @michaelgilligan61133]

Here’s a very near relative

Courtesy of the CIA

MichaelG.

.

 

.Ref. __ https://www.cia.gov/readingroom/docs/CIA-RDP83-00415R006500240002-1.pdf

[Michael GilliganParticipant @michaelgilligan61133]

… and a translation:

Object marking device
To mark certain preparation sites, which later
If you want it to be easy to find again, we supply one
Marking device from Winkel-Zeiss, Göttingen. Around the
The specimen site is marked with a diamond on the coverslip
surface, for uncovered objects in the object plane
Circle scratched, the radius of which can be adjusted on a scale.

MichaelG.

.

I would draw your attention to the word ‘diamond’ and suggest you make a very careful inspection of the tip of your device.

[Michael Gilligan]

On Michael Gilligan Said:

… and a translation:

Object marking device
To mark certain preparation sites…

.

I would draw your attention to the word ‘diamond’ and suggest you make a very careful inspection of the tip of your device.

In the event Old Mart doesn’t find a diamond, and I’m sure he would have noticed one already, could it be that his tungsten marker isn’t for a conventional through-light microscope?   Their delicate glass slides and cover-slips wouldn’t take kindly to blunt tungsten!

How about this accessory being for a Metallurgical Microscope?  On these a hard material is viewed directly, no cover-slip, and hence no need for a diamond.

Sad story: after finding astronomy was too cold and I need my sleep, I switched to microscopy, a deep hobby that doesn’t require a workshop.   Approaching retirement, I bought a microscope, digital camera, and metalworking tools, expecting unlimited time to enjoy all of them.   Silly me, Model Engineering leaves no time for microscopy!   If you take a handful of grass and bung it in a jam jar half full of water, there’s at least a year’s work in watching developments.  The learning opportunity is unlimited:  dyes; different types of illumination; slide preparations; which lens; best magnification; measuring; and identifying cell structures, bacteria, animalcules and much else.  I just don’t have enough time!

Dave

[Michael GilliganParticipant @michaelgilligan61133]

My working-assumption, Dave was that the original diamond may have been dislodged at some time in the device’s long history.

MichaelG.

.

Edit:__ careful comparison with the ebay offering that I linked earlier would be useful, I think.

[SillyOldDuffer]

On SillyOldDuffer Said:

 

Sad story: after finding astronomy was too cold and I need my sleep, I switched to microscopy, a deep hobby that doesn’t require a workshop.   Approaching retirement, I bought a microscope, digital camera, and metalworking tools, expecting unlimited time to enjoy all of them.   Silly me, Model Engineering leaves no time for microscopy!   If you take a handful of grass and bung it in a jam jar half full of water, there’s at least a year’s work in watching developments.  The learning opportunity is unlimited:  dyes; different types of illumination; slide preparations; which lens; best magnification; measuring; and identifying cell structures, bacteria, animalcules and much else.  I just don’t have enough time!

Dave

An old colleague of mine does all his astronomy from an armchair, with telescope under servo control, CCD camera, just needs to tell it where to point!

[old martParticipant @oldmart]

The tip of mine is definitely carbide, but I had neglected to mention that the thread was not the industry standard RMS but slightly smaller. It now has a standard fitting, although to get the shortest possible length extension, I had to use epoxy with a turned stump of a scrap objective. The length is now 50.5mm, originally about 45mm and the length increases 0.7mm when it cams downward to mark. The marker may well have been used for other surfaces than glass slides,

[Author]

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