This is a fun little project I finished a few evenings ago; a homebrew 500x digital microscope for all your biohacking needs, made from an old webcam found in the trusty junk box.

Read on for a mini-howto and some captured microscopic images.

A webcam usually uses just a single lens focusing straight onto the CCD imager. And usually, the lens is mounted in a little rotating bezel. By removing the lens bezel and reversing it, so that the lens is much futher from the CCD than usual, the focal length is reduced to a few millimeters in front of the lens – making for a surprisingly usable microscope.

You can see the arrangement in the pictures; I just taped the lens assembly on backwards having unscrewed it from the mount.

I removed the green LED the webcam had and used the handy 5V to power three white LEDS mounted below the slide platform (I think that’s called the stage on real microscopes). The LEDs have a little switch to turn them on and off, as sometimes you want your specimen lit from above instead of below. They’re mounted on a blob of bluetack to allow the beams to be adjusted easily.

The slide platform itself is a piece of transparent plastic epoxied onto the top of a large bolt, which is screwed into a fixed nut. This allows me to bring the slide into perfect focus by rotating the platform and bolt. Real microscopes focus by moving the lens rather than the specimen, but this was easier to constuct and although a little fiddly in use becomes easy with practice.

The quality of the images obtained was a lot higher than I expected – check them out below. Magnification is around 500x and it’s possible to see animal cells. Click an image to enlarge it.

   

   

Highly recommended as something to make on a rainy weekend