This guide will show you how to turn your smartphone camera into a digital microscope. If you have to buy all supplies it'll likely cost you under $5 but you might have all you need already.
I'm going to explain the very simplest way to make this. But of course you can take these basics and build it up as much as you want to. I'll include an example of what others have done later.
Get yourself a laser pointer. Any cheap one will due. I got this one at walmart for about $3 in the pets section.
Unscrew the top off the laser pointer. You'll see a black "srew" in the center. This is holding the lens in place.
Unscrew that and you'll see the lens underneath it. Be careful. There's a spring under the lens so it could pop the lens out. Do this over a table so you won't loose the tiny lens.
The lens will come right out. This lens is the perfect size lens to put over the camera lens on your phone. So that's what we're going to do.
Cut two thin strips of tape and tape the laser pointer lens over the camera lens but don't cover the center of the lens. You could simply tape it to your phone but I taped it to a cheap iPhone case.
That way I can remove it and put it back on at will. So this case is my microscope case.
Your camera will have to be very close to the object you're looking at. Experiment by placing your phone on objects of different thickness to get it to focus. You can also "teeter totter" to focus.
This is just an example. This is a fingernail file. It's very hard to take pictures while you're holding the phone because very tiny movements really effect the picture this close up.
I had to test my fingerprint. :)
I couldn't take a screen shot of this one because it moves my phone. But look at the bottom. If you use a magnifying glass app you can zoom in even closer.
To capture really small things. It's better to get more elaborate on something transparent with a light source under the transparent platform. So you can use slides like a real microscope.
Here's a popular set up. Use nuts, bolts and washers to make two platforms of plastiglas. The platforms are adjustable to focus and an LED light. The lens is in the top platform.