Check out :http://micro.magnet.fsu.edu/primer/tech ... intro.html
You can safely ignore the central modulator. You're not likely to find one.
Scroll down and take the Interactive Tutorial. You'll need Java installed. The tutorial is
not necessary but I've found it helpful.
Edmund Optics sells polarizing material for too much of course ($20 ?), but it's
probably the thinnest material you'll find and that's good.
Many thanks, Radazz and Brad.
I've read that link many times. However, because it says that "Drawings of the modulator plates shown in Figure 2 are exaggerated and increased in size for the purposes of this discussion", I wanted to see how it looks like in a real-life example.
It's not perfectly clear from Radazz picture, but it helps.
This is what my DIY solution looks like:
Wild achr.apl. condenser with a slit cut from an old library card slid into the filter holder beneath the condenser.
I think the back focal plane looks similar to Radazz's. However, I think that your slit is a little longer? I'm going to try a couple of different lengths and widths to see how it impacts image quality.
I already have some polarizing film and tried to mask half of the slit as described in the link above, but I didn't really feel that it changed the effect as much as I'd hoped when I rotated another polarizer over the field lens. Will keep experimenting, though. Now that I have it working it's easy to make slight variations.
Radazz, have you tried the slit condenser with some other non-phase objectives? Mine gives really nice 3-dimensional oblique illumination with my other 20x and 40x objectives, and something similar to oblique dark field with my 10x. Very nice, actually! Much easier to switch between brightfield and HMC for me