What was this weird Leitz system used for?

[josmann]

Saw this rather strange microscope system on a government auction site. Two polarizing Laborlux scopes piped to a common binocular head. I'm assuming the images from each scope are overlapped rather than just being able to switch between one or the other but who knows. What do you guys think? Too custom to know for sure or does somebody recognize this configuration?

8445_21588_5.jpg (103.61 KiB) Viewed 2379 times

In case this was on your Christmas list and Santa didn't come through for you: https://www.govdeals.com/index.cfm?fa=M ... cctid=8445

[deBult]

Typically used for sample comparison in criminal investigations.

(E.g. for drowned victims: identical diatom sample in lungs and waterway).

[josmann]

Typically used for sample comparison in criminal investigations.

(E.g. for drowned victims: identical diatom sample in lungs and waterway).

Ahhh, that’s it - fascinating! I had no idea such systems existed and were commonplace. And polarization makes a lot of sense as an added parameter in that case as well to help match materials and whatnot. Thanks!

[BramHuntingNematodes]

Bullet casings are a famous example cf the great mouse detective

[PeteM]

I have one of the American Optical/Reichert versions. Pre-pandemic it was a hit with kids. As suggested above, the two images can be seen side by side or superimposed.

[wabutter]

This particular system, simply known as a comparison microscope, is used in the trace evidence labs for forensic investigations. Typical samples would include hair, fibers, glass and paint chips. To a lesser extent, building materials, minerals and other samples that would be suitable for use on a PLM. A/O Reichert built their system off the Series 10, 110 and 410 Microstars using the same bridge used with the UFM Comparison Macroscope for Fired ammunition component comparison.
Particularly challenging for this system is getting the illumination balance between the two microscopes, intensity, color and distribution across the field of view is difficult to achieve as many variable enter into the set up.
The latest iterations of these systems used bifurcated randomized fiber optic bundles so the source was the same on both scopes and only the positions set up factors entered in the getting the light balanced. Of course capturing the image was also complicated as the camera detectors were more sensitive than the eye, so getting homogeneous fields was very difficult to the camera. Shade correction software algorithms were one way to correct for this problem.

[wabutter]

I just took a look at the bid site and a side picture. This system has a unique to Leitz ( Leica) component installed between the lamp house and the microscope stand. It is a variable color filter system that was used to help balance the color between the left and right scopes. As I mentioned earlier, tne introduction of the bifurcated Fiber bundle help simplify that process.

[Rossf]

The history of comparison scopes is fascinating-first used in an American court in the 1920’s-I read originally just the resultant photos were shown but the jury wasn’t having it-they trusted the idea of comparison scopes but felt wary of being shown just photos as the public was already aware that photographs could be doctored (think of those famous “real” photos of fairies in the garden from a bit earlier -so to satisfy the jury the whole comparison scope had to be set up in court so jury members could see for themselves the striation marks on the bullet. Amazing hey?!
Regards ross