I had a go today at observing a commercial slide of Hydra spp. through crossed polarisation filters on LOMO Polam P-113 Polarising Microscope. The first picture shows the slide with plain polarisation (effectively bright field). The second is where the one filter is rotated nearly 90 degrees. Initially, I thought the bright dots were some birefringence (small bright dots) from the mountant used on the slide, but now I think they are hot pixels on the camera! The specimen interesting becomes nearly invisible – in fact if I rotated to 90 degrees exactly, it did become invisible – this is a little short of that so that you can see specimen in background. Much longer exposure required.