This looks great, and AWESOME diagram! @maxliboiron do you think we have to flip the dissecting scope so that the materials can be on the same side of the slide as the camera, and don't fall off? i.e. the camera looks down at them? 

Or do you think we'd be able to focus through the bottom of a glass or plastic slide or container to view them from below?

Thanks!

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A bit more info on this back at this question from some months back: https://publiclab.org/questions/stevie/12-08-2017/could-the-raspberry-pi-microscope-be-used-for-looking-at-microplastics-found-in-ocean-water

In a perfect world, you wouldn't be looking through plexi at your marine plastic because plexi has characteristics of plastic (scratches, reflection, etc) that might obfuscate or layer on what you're trying to analyze. Sometimes the clue that you're looking at a plastic and not paper, a shell, or an exoskeleton is very minute, and I'd worry that for tricky cases the plexi (or even glass) between the viewer and the plastic would sway visual interpretation. So in short, it would be best to flip it, but also to have the lens and the stage farther apart, as the diagram shows.

This image shows our two store-bought scopes (compound on the left, which we rarely use, and the dissecting scope on the right, where you can see light coming from below the stage and above, as well as the relative distance between the lens and the stage).

Thanks for the reply Max! So, what we are really looking at for conversion is adding a secondary light source as seen in the image below.

Looks about right to me.