What objectives are you using? It is very important (!!!) to use Olympus ones that are compatible with the Nomarski system! I don't know what ones were recommended for use with the older BH, but with the "LB series objectives" that arrived with the BH2 the ones recommended for DIC are the Olympus S Plan Achromats. (I also use the S Plan Apos and they also work well.) Others
might work OK, but if you are trying to sort out problems one of the very first things you need to do is be sure you are using compatible objectives. (Once you get things working properly then you can try other objectives to see what happens).
If you are using an Olympus S Plan Achromat and have these problems I'm really suspect the "extra" glass in the BHTU. If you have some time try this with both the old and new upper sliders ...
First be sure the red dot on the BH2-NA intermediate tube is mounted on the microscope to that red dot is in line with the red dot on the microscope (as you show in your pictures).
- Using a 10X or 20X, find a very small subject (like a speck of dust on the slide) and put it in focus. I use my 20X but it doesn't really matter.
- Insert the upper DIC slider fully, and turn the sliver adjustment knob fully clockwise (It should be all of the way "in").
- Be sure the condenser polarizer is in the light path.
- Put the condenser turret into the the
brightfield position (
no condenser Nomarski prism in the light path!) .
- Pull out one eyepiece and look down the tube at the back of the objective. While looking down the eyepiece tube at the back of the objective, slowly rotate the
condenser polarizer and see it you can get a pattern that looks about like this:
If you can get such a pattern leave the polarizer at that rotational angle.
(If you can't get a pattern that looks about like this than I doubt you'll get decent DIC until you figure out what is wrong).
Now put the eyepiece back in. In the condenser turret, rotate a Nomarski prism into position and use the appropriate objective for that prism. With the upper adjustment knob in the fully clockwise position, very little (if any) DIC relief effect or coloration will be noticed. As you rotate the adjustment knob counter-clockwise you will see a change. The DIC effect increases and the background gradually becomes a darker gray. You will reach a point where it looks almost "pseudo" darkfield, and then goes back through progressively lighter shades of gray and the DIC "shadowing" effect now appears to come from the opposite side. As you continue to rotate the adjustment knob you start to get into yellow, orange, pink, magenta, blue and cyan background colors. The best DIC effect, contrast and resolution appears before and after the "pseudo" darkfield position. The colorful settings are... well.. COLORFUL... and (for my tastes) best used with restraint with biological specimens. Although I often check, because sometimes this "optical staining" does indeed bring out certain features better. For crystals, air bubbles and such dial it up to your hearts content!
). It may mean absolutely nothing and the glue guy was just having a rough day... but it might mean that it has been "worked on" at some time.
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