Metalography Microscope: Olympus BH2

I finally managed to get my hands on a metallurgical Olympus BH2 microscope second hand, for a very good price, including:

• The strong BH2-MJL base
• The BH2-MA vertical illuminator
• An ergonomic trinocular head (a rare model) with the original 10x eyepieces
• 5 metalographic objectives

The BH2-MA include a tube lens and controls for two apertures, but also filter slots.

It’s used to illuminate the sample from the top (light is coming from the objective).

Objectives

The nosepiece have 5 objectives:

• MSPlan 5x 0.13 ∞/- f=180
• MSPlan 10x 0.30 ∞/- f=180
• MSPlan 20x 0.46 ∞/- f=180
• LWD MSPlan 50x 0.60 ∞/- f=180
• Plan 80x 0.95 ∞/- f=180

Here are pictures of the same chip using each objective.

Important note: each image is cropped from a picture taken afocally, by hand, with a Nikon Coolpix S600 camera through a 10x eyepiece.

The Plan 80x give a very blurry image. At the time I was not aware that you have to tune the aperture diaphragm of the vertical illuminator to match the objective. Resulting on a very poor image with higher magnification.

Future plans

Now that I have a good microscope, I want to make an automated pipeline to capture panoramas semi automatically.

This will require:

• An USB microscope camera that I can control from the computer
• A CNC stage to move the sample under the microscope automatically
• A software pipeline to capture and stitch the pictures

For low magnification I can take pictures by hand, but the higher the magnification, the more pictures you need to reconstruct a complete panorama.