Eyepiece w. the smallest magn. for the self-made stereo mic

Adalbert · Post by **Adalbert** » Fri May 17, 2019 7:43 am

Hello everybody,
Does anybody know how to build a microscope for the small magnifications?
Something like stereo-microscope but mono :-)
What lens could be used as an eyepiece (with the smallest magn. as possible)?
For the objectives : finite Zeiss or infinite NIKON/Mitutoyo.
BR, ADi

enricosavazzi · Post by **enricosavazzi** » Wed Jun 05, 2019 12:34 am

My experiments with camera lenses repurposed as microscope eyepieces were not encouraging. In most cases I had to keep my eyes extremely close to the lens, and sometimes it was simply impossible to see anything more than a very narrow field of view.

Another problem is that typical microscope objectives are designed to work best with 10x eyepieces. You can indeed use eyepieces with lower magnification, but the result is that the angle of view decreases accordingly, so you do get a lower magnification but you do not see a wider field of view of the subject.

So my recommendation is just to use a good high-eye-relief 10x eyepiece with a reasonably wide field of view (you can get a field number up to about 26, although 22 is already quite wide). If you need low magnification, simply choose a low-magnification objective with an image circle at least as wide as the field number of the eyepiece. Most recent Nikon and Olympus eyepieces have no built-in color compensation and work well with most recent infinity objectives, including Mitutoyo M Plan Apos. Finite Zeiss objectives require a matching correction in the eyepieces, so you must use matching Zeiss eyepieces.

Without prisms or relay optics, the image in the eyepiece will be inverted. I guess you already know this.

Adalbert · Post by **Adalbert** » Wed Jun 05, 2019 8:39 am

Hello Enrico,
Thank you for the hints!
I would like to assemble a kind of a stereo-microscope but mono.
I don’t need stereo because I cannot see stereo

So, I could use a monocle telescope (e.g. 8x) and a lens 200mm (e.g. Sigma LSA or CANON EF 70-200L) as in the following DIY-solution (but mono)
http://www.funsci.com/fun3_en/uster2/uster2.htm

The second solution (expensive) could be Zeiss Mono:
https://shop.zeiss.de/ZEISS-Mono-4x12-T ... 7006205004

So, I’m looking for the monocular 8x or zoom at the moment :-)
BR, ADi

Scarodactyl · Post by **Scarodactyl** » Wed Jun 05, 2019 9:25 am

Do you need two eyepieces with one view, or only one eye?
If you only need a mono view what you can do is buy a misaligned stereo microscope for peanuts and only use one of the oculars at a time.

Adalbert · Post by **Adalbert** » Wed Jun 05, 2019 9:34 am

Hello Scarodactyl,
Yes, of course but this is no challenge :-)
BR, ADi

Adalbert · Post by **Adalbert** » Wed Jun 05, 2019 1:24 pm

Hello everybody,
I have just tested the NIKON EL Nikkor 75mm with the eyepiece CZJ PK10x / 15,5.
This combo works very well.
BR, ADi

dolmadis · Post by **dolmadis** » Thu Jun 06, 2019 12:09 am

Hi

Glad you found a combination that works for you.

Could you please post a photo of how you mounted them together?

And your intended use and context?

Thanks

John

Adalbert · Post by **Adalbert** » Thu Jun 06, 2019 1:01 pm

Hello John,
I would like to assemble a DIY magnifier with a long working distance based on the lenses I already have.
e.g. EL Nikkor + PK10x :

BTW, it can be mounted by the step-down rings
BR, ADi

dolmadis · Post by **dolmadis** » Thu Jun 06, 2019 1:22 pm

ADi

I travel quite a bit at the moment but have to "travel very light" and packed into competing space in luggage especially with family.

I was interested because your idea also seems to fit with my need.

Thank you so much for sharing your work.

BR

John

enricosavazzi · Post by **enricosavazzi** » Fri Jun 07, 2019 8:39 am

The idea of using a binocular + CMO solution might be just what I need for field use. I have a Pentax Papilio 6.5x 21 and with an objective of rather low magnification it might make a good field stereomicroscope.

dolmadis · Post by **dolmadis** » Fri Jun 07, 2019 9:00 am

Hi Enrico

Do excuse my ignorance but I do not recognise the term "CMO solution" but it may be an increasingly senior lapse !!

So would you mount the Binocular on an easily erected stand or frame for convenience/stability?

And use an objective from a fairly standard stereo mic?

Thanks for posting and extending this quest.

BR

John

Alan Wood · Post by **Alan Wood** » Fri Jun 07, 2019 10:05 am

CMO = common main objective

https://www.microscopyu.com/techniques/ ... microscopy

Alan Wood

dolmadis · Post by **dolmadis** » Fri Jun 07, 2019 10:09 am

Thank you, Alan.

enricosavazzi · Post by **enricosavazzi** » Fri Jun 07, 2019 10:51 am

dolmadis wrote:[...]
So would you mount the Binocular on an easily erected stand or frame for convenience/stability?
And use an objective from a fairly standard stereo mic?

I would try first without a focusing stand and stage. For magnifications up to 2x or so, I may manage in the field without a stand and focuser. My binoculars have a tripod mount that can be used for attaching a home-made or 3D-printed support to hold the added objective at the right position.

The link quoted above suggests using an achromat objective from larger binoculars, but a generic achromat with a diameter of 40-50 mm will probably work. I also have a few add-on magnification lenses (Raynox, Sigma Life Size etc.) that might be suitable and are worth testing.

A dedicated stereomicroscope objective is likely both too expensive and too heavy for this use.

dolmadis · Post by **dolmadis** » Fri Jun 07, 2019 11:04 am

Thanks............Will experiment..............

BR

John