Help with Leitz Laborlux-12 + DSLR setup

[karhukainen]

Hi there, I'm new to this forum and have already found some really useful information on here. What a great resource!

I previously had a Leitz SM-M (I think) binocular microscope and a Lomo MNF-12 photo adapter. The combo worked fine together. I recently got a standard version Leitz Laborlux 12 with binocular head and I need help figuring out how to make it work with my Canon 5D IV. I tried photography with the Lomo tube and not that surprisingly the images get blurred towards the corners. The photo tube is also a little loose on the Laborlux. Here are a few images of the setup. One of the objectives on the new microscope seems to be for 170mm tube length (which is what my old system was) but the rest are 160mm. The Lomo has just two tube lenses (not sure this is the correct term): 7x and 10x, but is the tube too long no matter what tube lens is used?

The example image of a cyclop is a bit artsy (I'm a photo artist), but it probably shows the problem well enough.

Any thoughts?

[MichaelG.]

Welcome aboard !!

This famous inter-office memorandum should probably be your first reference:

http://www.science-info.net/docs/leitz/ ... m-Memo.pdf

After that, try taking some boring shots of something like a stage micrometer.
... I do like the arty one, but it’s difficult to analyse anything from it.

MichaelG.

.

Edit: This document explains things in a rather more friendly fashion:
http://www.microscopy-uk.org.uk/mag/art ... on%201.pdf

[karhukainen]

Haha, thanks. What should I be looking for in the memo? Even though I've owned a microscope for years I didn't use it a lot and I'm definitely new to more technical aspects.

Here are a few less artsy images. The first one was taken with the 10x achro objective and the second one with the 20x.





And larger versions. The first one was taken with the 4x objective for 170mm system.
https://imgur.com/W96uwB0
https://imgur.com/QM3aEHh
https://imgur.com/pCHs39b

[MichaelG.]

What should I be looking for in the memo? Even though I've owned a microscope for years I didn't use it a lot and I'm definitely new to more technical aspects.

... You should be looking to get a basic understanding of the relevance [or otherwise] of the mechanical tube length : 170mm vs 160mm

The first reference in the second item I linked is pretty definitive, but it’s quite a ‘heavy’ technical book, and you may not need to go there.

MichaelG.

[MichaelG.]

And larger versions. The first one was taken with the 4x objective for 170mm system.
https://imgur.com/W96uwB0
https://imgur.com/QM3aEHh
https://imgur.com/pCHs39b

4x looks free of Lateral Chromatic Aberration, but is not very sharp at all
10x has a lot of CA at the sides, but is good at the centre
20x is cleaner, but shows the same trait

All three objectives are ‘only’ Achromats, so some of this is inevitable ... but I think a photo eyepiece with better compensation [*], and some experimentation with the tube length, should improve things.

MichaelG.

[*] I believe that LOMO 7x is closer to Zeiss than Leitz in its compensation
... but I’m sure someone will correct me if that’s wrong.

[karhukainen]

What should I be looking for in the memo? Even though I've owned a microscope for years I didn't use it a lot and I'm definitely new to more technical aspects.

... You should be looking to get a basic understanding of the relevance [or otherwise] of the mechanical tube length : 170mm vs 160mm

I'm aware that there are different lengths but don't really know what it means in practise. I'd assume the tube should be shorter and the photo eyepiece (is that what they are officially called?) should have less magnification, but how do I know exactly what to look for?

[karhukainen]

Oh and I already looked before if I could find the referred book but with no luck. I'm also confused about the 4x objective because yes, it's not sharp at all, but I would have understood that out of all objectives it would be the one that works best with the photo set (since the set works fine with the 170mm system).

[MichaelG.]

... but how do I know exactly what to look for?

I’m truly sorry, but I don’t have the skill-set to teach you that

The Leitz memo gives some very strong clues that the mechanical tube length issue can be ‘worked-around’ by selecting the right components, but you will almost certainly need to experiment.

I am not familiar with the E1 objectives but, as I mentioned earlier they are Achromats and the performance will be limited ... For optimum photographic use you would ideally use PlanApo objectives [which are better corrected for colour, and also produce a flat image] : But we all have to work with what we have available.

In those circumstances : Finding the right photo-eyepiece and the right tube length for a particular objective can be an ‘adventure’.

Unfortunately, I can only suggest that you do some reading and then start playing !
A few millimetres change in the tube length might make all the difference to curvature of field.
... I know, for example , that the visual version of the 7x LOMO eyepiece can be converted into a good approximation of your photo version, by simply lifting it about 5mm.

Do some experiments and post some photos of the results, so that we can all comment [and learn]
... If you happen to come into a fortune; buy some exotic lenses ... but until then, enjoy the ride.

MichaelG.

[MichaelG.]

The Leica BME microscope uses the E series objectives ... so it may be worth noting the part numbers for the E2 and E3 versions for future reference:

http://www.mcbainsystems.com/pdf/Leica_BME_broch.pdf

MichaelG.

[karhukainen]

Okay, thanks. Unfortunately I can't afford several unsuccessful experiments, so I if there's anyone else who has further ideas, I'd really appreciate it!

[MichaelG.]

Okay, thanks. Unfortunately I can't afford several unsuccessful experiments, so I if there's anyone else who has further ideas, I'd really appreciate it!

Your experiments could start with simply lifting the eyepiece a few millimetres and checking for any change in performance.
... a piece of tape or a rubber band would suffice.

MichaelG.

[MichaelG.]

Okay, thanks. Unfortunately I can't afford several unsuccessful experiments, so I if there's anyone else who has further ideas, I'd really appreciate it!

Your experiments could start with simply lifting the eyepiece a few millimetres and checking for any change in performance.
... a piece of tape or a rubber band would suffice.

MichaelG.
.

.

Unfortunately, I can only suggest that you do some reading and then start playing !
A few millimetres change in the tube length might make all the difference to curvature of field.
... I know, for example , that the visual version of the 7x LOMO eyepiece can be converted into a good approximation of your photo version, by simply lifting it about 5mm.

Do some experiments and post some photos of the results, so that we can all comment [and learn]