Eyepiece/Okular Zeiss Jena DDR "K","C","A" ?

[kalleboy]

Hello
Ø23.2mm Eyepiece/Okular Zeiss Jena DDR 1980:
What means these extra markings: ?
1.) Empty no marking
2.) "K"
3.) "C"
4.) "A"
5.) Other letters or kombinations...

- Which one is the best and which the worse choice ?
- Some seller said "K"=means color corrected, but what does "color corrected" really mean ?

[JB]

Hello Kalle,

High magnification achromat objectives and apochromatic objectives show "chromatic difference of magnification" or "lateral colour" in the intermediate image. http://olympus.magnet.fsu.edu/primer/java/aberrations/chromatic/index.html

This causes colour fringes in the microscopic image. Zeiss designed eyepieces that have the opposite "chromatic difference of magnification" compared to the objectives. This compensates the lateral colour and you get a final image without colour fringes.

Before 1980s, Zeiss Jena produced different eyepieces for different objectives:

"A" is for use with low magnification achromatic objectives (no colour compensation)
"K" for use with high magnification achromat objectives and apochromatic objectives (with colour compensation)
"PK" especially for planachromats and planapochromats; they also work for high magnification achromats and apos

"C" I have never seen for Zeiss Jena (for Zeiss West it means "compens" and was the lowest grade of compensating eyepieces)


On Zeiss Jena objectives:

"A" objectives do not require compensating eyepieces
"C" objectives require compensating eyepieces

Hope that helps,

Jon

[plaenerdd]

Hallo Kalleyboy

The best chois is the eyepiece that harmonise with your objektiv. I like the "PK 10" cause I normally use Apochromats. It is also good for taking Fotos.
Gerd

[kalleboy]

- Can I use "West" eyepieces on Jena microscopes ? Was it something like KLI or KPI that was the best with West eyepieces ?
- Now I have A10x(14), so "A" is bad choice and should buy only "PK" for best picture.
- Is the lowest magnification I can get 5X Zeiss(23.2mm) or do 2x or 1x exist ? (The 10x has too big magnification.)

[JB]

Hi Kalle,

The "best" depends on your objectives! You need to tell us what objectives you have

You can use Zeiss West eyepieces but you will lose parfocality for low magnification objectives (< 16) so you will need to re-focus when you change objectives.

If you have planachromat objectives, "A10x" isn't the best choice yet. PK 10x or even PK10x(20) would be better. The Zeiss West equivalent would be the "Kpl W 10x" (but as I say, you loose parfocality).

Jon

[kalleboy]

Now I have 3.2x lens and 10x eyepiece. So total 32x magnification.
I want to replace current eyepieces Jena A10x(14) with smaller 1x, 2x or 5x Zeiss DDR eyepieces.(They are too big for coin/Munzen viewing)

+ I have also seen the lowest objective/lenses being Zeiss 2.5x ? "Planapochromat or so" lenses on ebay...

[plaenerdd]

Hallo Kallyboy,
For the 3,2-objektiv you can use an anmaket eypiece or en "A", but it ist not the right mikroscop for numismatics! An stereomikrokop would be better.
If yuo want to buy objektives, you must be verry careful. You can only use objektivs for 160mm length of tubus. They had to be maket with 2,5/0,10/160 - for exampel. The first number tells the magnificatin, the secand the "numerische Apertur" (dont know the englisch Word) and the third the length of the tubus. If there is an laying "8", is means infinity-optik. This you can't use on yor mikroscop! The "-" means the use without a coverglas.
Gerd

[kalleboy]

Hi
I was going to buy/upgrade also some infinity objectives...(Thinking they are the best I can get...)
- Why I can not use these infinity( 8 ) objectives on old Zeiss DDR 1980 microscopes ?

Seems microscopy is awfully difficult to understand and Zeiss has made it very difficult because of all these many different eyepieces and objectives.(Seems like a money making scam)

I have come to a conclusion (from the expreriences of looking Zeiss Laboval 2, 1980 CNC-build quality and aluminium casting) that Zeiss is not a good manufacturer can you give me a better manufacturer name ?
+ Is Nikon, Olympus or Leitz a better brand ? Which is the best microscope brand ?

[plaenerdd]

Hallo Kallyboy,
finite and infinite are different archtectures of microckops. You are using an LABOVAL, I'm right? It's an microscop with 160mm length of tubus. It is finite. If you want to use infinite objektives you need a specel lens, the Laboval does not have and: The infinite microskops objektivs have an other thread. They will not fit in the objektv-revolver of the LABOVAL. You can only use objectives with RMS-thread.

It's not for printing money, is a question of technicel historiy and different needs. "normal" achromats are cheap because they are not so high corrected like apochromats. For "normal" use they are good, but not good enough for some special applications. So they bild better objectivs, but they need other eyepieses. It is easyer to correkt the colors and the flatness in the two pieses you use: The objekciv and the eyepice. Modern objkektivs (mostly infinte-optics) are full correkt. You need only a simpel eyepiece and for photography you need no eyepies. In the finte-optics like in the LABOVAL objektiv and eyepiese are one unit. You need a eyepiese also for photography.

If you ask for the best brand, you will get different answers: The Olympic-users will say "Olympic" and the Zeiss-users will say "Zeiss". And it is also a question of history: between 1945 and 1990 there are Zeiss-Jena (east) and Zeiss (west) in Oberkochen.

For your application (coins) I would sell the LABOVAL and look for an stereo-microscop like the MBS-10
Gerd

[kalleboy]

I stuck with this one paid too much 175€ and a stereoscope cost another cirka 200€.
I have looked over better PK eyepieces: (and things got difficult)
- What is the difference between short PK and long PK(rubber) eyepieces ?
- What means "/W" ?
- What means "m" ?
- What means "Pol" in red color ?
- What means "mPol" ?

[plaenerdd]

Hallo
"Pol" means "for polarisation"
"W" means "wide" (30mm, not 23,5mm)
"m" I dont know. maybe its means "measurement" and has a scale inside.

The length depends on magnifikation: the shorter have higher magnifikation.
LG Gerd