Microscope Slide Microcosm

Create a realistic brightfield microscope photograph of a slide containing diatoms, pollen grains, and a few tiny microplastic fibers. Add slight vignetting, faint dust specks, and a subtle out-of-focus edge as if shot through an eyepiece. Include a small scale bar that reads '50 µm' in the corner. Color should be natural and slightly muted, like a real lab image.