Leitz microscopes: are uncompensated trinocular OK for photography?

[uski]

Hi!

Since this is a photography forum... maybe someone knows!

I have a few Leitz microscopes, and I managed to get trinocular heads for all of them.
However, I realize that Leitz split the corrections between the objectives, and the eyepieces (Periplan).

So when using a trinocular head without a Periplan eyepiece, the image that the camera sees is uncompensated and will suffer quality issues.

What I don't know, is how bad this is?
And, how can I fix it?

Is there a way to add an additional Periplan eyepiece in the trinocular head maybe, to add the correction?

I am just curious as to what others have done. The convenience of being able to look into the microscope with both of my eyes while still being able to take pictures, kind of precludes the idea of sacrificing one of the eyepieces for photography, like some people do, by adding a cellphone mount (for example) in front of one of the two existing eyepieces. I really would like to use the trinocular, but getting the maximum possible quality.

Thanks

[PeteM]

You can add a Leitz correcting eyepiece and shoot "afocal." Anything from a phone camera to a DSLR could be used, perched above the eyepiece.

One older, but still usable, approach used a Leitz eyepiece with threads that happened to match early Nikon Coolpix cameras. These will provide surprisingly good images.

Leitz also made photo relay lenses and adapters for 35mm film cameras - so those could be ideal for a full-frame digital camera. Figuring which ones to use gets a bit complicated because Leitz went through multiple generations (both short and DIN-standard parfocal distances and both 170mm and 160mm finite tube lengths) . . . and then went on the a few generations of infinite optics.

[Pau]

Yes, you need to place a Periplan eyepiece (or the scarce Orthomat W zoom lens) for doing the needed complementary corrections.
The most usual setup -and the one found in original Leitz adapters- is afocal.
Another option is to do eyepiece projection on sensor raising some millimetres the eyepiece of the phototube (see viewtopic.php?p=287887#p287887 )

General info about afocal: viewtopic.php?p=99265#p99265

There are many threads on this subject at our forum and also at other sites like https://www.microbehunter.com/microscopy-forum/ and https://www.mikroskopie-forum.de/

Search:
Leitz + afocal
Leitz + Periplan + afocal
Leitz + Orthomat
...and so on

[Scarodactyl]

This baby just came up on eBay https://www.ebay.com/itm/155684947136

[uski]

This baby just came up on eBay https://www.ebay.com/itm/155684947136

Ah dang, I missed it. But good find!

Thank you all for the info. I am pretty proficient with 3D printing and can 3D print adapters to hold lenses, objectives and so on.
But, I am super confused as to what to do. Can someone confirm my understanding?

I used this adapter before: Diagnostic Instruments D10NLC.
It does NOT have any lens whatsoever, which means that there is an image projected by something (the objective itself?) slightly above the trinocular metal tube, right?

I know that Periplan eyepieces expect to "catch" such an image around 10mm below the top of the eyepiece, so I think I need to align the eyepiece vertically so that this point coincides with the location where the sensor was when I was using the D10NLC.

And once I do that, to do afocal photography, I need to have a regular digital camera lens on top of the eyepiece, to focus on the image "inside" the eyepiece. I think I will need an objective that can be macro capable because it will be very close, right?

Am I on the right track? Thanks!

[Pau]

And once I do that, to do afocal photography, I need to have a regular digital camera lens on top of the eyepiece, to focus on the image "inside" the eyepiece. I think I will need an objective that can be macro capable because it will be very close, right?

Am I on the right track? Thanks!

No, you don't need a macro lens, in afocal the camera lens must be focused to infinite* usually just a standard prime lens is good if the entrance pupil is not too recessed.

Did you see my thread?

In most microscopes the objective "primary" image is expected 10 mm below the end of the tube but in Leitz 170 corrected microscopes it is expected 18mm bellow the end of the tube. This is not problem if you use both phototube and eyepiece of the same 170 standard.

Pictures and data of your microscope, in particular of the phototube and also of the eyepieces you have would be convenient to give you more precise advice.


* because the eyepiece image is "focused to infinite" and your eye focuses it in your retina.

[uski]

Hi,

Thank you so much for your replies. Using the guidance you have provided I was able to build a custom adapter for my purpose.
3D design: https://www.thingiverse.com/thing:6156060

This adapter allows connecting an old 12MP Nikon Coolpix S5100 to the trinocular head of a Leitz Dialux 170mm microscope.

There is a Periplan 10x "glasses" eyepiece inside, that provides the necessary objective correction. So this is an "afocal" setup.

It's a proof-of-concept, I'll probably tweak the adapter to allow connecting a more suitable camera, but that said, it works fine for basic photography!

The advantage of this camera is that it has a 5x zoom lens so I can choose if I want to crop the eyepiece image (to get full-field coverage on the resulting picture) or have the widest FOV possible (but have circular vignetting). I can also easily shoot 720p videos. So it's pretty cool.

I did some testing with a NPL Fluotar 100x infinity/0 objective looking at a microchip die through a 1x infinity epi-illumination adapter and the picture quality is really good.
Pretty happy with this metallurgical-style setup!

Here is an image capture without any zoom:

And with zoom:

Crop:

I have a "red dot" eyepiece on its way, which might improve the picture quality even more, but I think I already have a pretty good setup. I also need to clean the eyepiece very well, there are 3-4 dust particles inside which you may have seen in the pictures above as darker areas.

I also have 160mm microscopes/trinoculars so I will probably make a version for these, too.

Exciting stuff! Probably a step-up in terms of image quality from my previous setup without the compensating eyepiece.

[uski]

Acetaminophen crystal, using this setup

I would like to improve the sharpness. It is possible my measurements are not 100% accurate, causing the eyepiece to be a bit misaligned vertically.

Additionally, I am using a regular high-eyepoint eyepiece and not a "red dot" eyepiece, so that could be a factor too. And this is a regular "NPL" objective, but one appropriate for DIC (the later infinity objectives with red text), so it should be relatively strain free.

But overall, it's working!