Webcam Microphotography

My first attempts at digital microphotography used an IBM 'PC Camera' USB webcam. Using a CMOS imager chip with a 320 x 240 resolution, it's certainly not the best imager available on the market, but I happened to have one handy in my junk box.

Some websites have reported success using a jeweler's loupe magnifier as a macro lens, attaching it to a digital point-and-shoot camera. I started my experiments with a 5x loupe, but quickly found that the webcam itself could be focused on objects a mere 1/4" away from the front of the focus ring. Using the camera's maximum resolution, and viewing the image on a monitor set to 1024 x 768, this yielded a magnification of 12x. Adding the loupe actually decreased the magnification, since I had to hold the subject further away from the lens. Here's some images captured with the camera alone:


Tip of ballpoint pen

Back of electrical connector package

Pocket lining complete with lint

The back of my hand

My finger

My fingertip
These images were taken with available light (fluorescent), and are unprocessed.

Additional webcam macro investigations here.

While 12x is by no means a 'high' magnification, the scale does lend itself well to imaging such subjects as flowers, insects, and other small subjects. A support for the camera, adjustable lighting, and a stage to support the subject would all likely make for better images due to better control of the focus and light. The depth of focus is very small, and this makes it a challenge to hold the webcam by hand while taking images.

For reference, here's the ballpoint pen using the camera with the focus set to infinity, and a 5x jeweler's loupe:


Ballpoint pen, webcam with 5x loupe

Time for some higher magnification. For this series, I used the webcam again with focus at infinity, held to the eyepiece of a 30x toy microscope:

Ballpoint pen, webcam and 30x microscope


This method of camera-microscope coupling is known as afocal. It tends to suffer heavily from vignetting, the black circle around the field of view, but is handy because it requires very little to no modification of either the camera or optical instrument. This method can also be used with telescopes and binoculars.

Here's the collection of eqiupment used so far:



They are an IBM "PC Camera" USB webcam (upper right), an "Uncle Milton Scope It Out" 30x portable microscope (left), and a 5x jeweler's loupe (lower right).

The next step was to try the webcam with a standard compound microscope, in this case an Edmund Scientific beginner microscope. These images were taken with an unmodified webcam by simply holding the webcam up to the eyepiece, a technique known as 'afocal':
Bee mouthparts, at 40x, 100x, and 400x
These images suffer from severe vignetting, an effect caused in this case by having the webcam lens too far away from the microscope eyepiece (the case of the webcam prevented holding the lens any closer). They also show the difficulty of exactly aligning the webcam with the optical axis of the eyepiece, resulting in off-center images.

The answer to the vignetting problem here is to move the webcam lens closer to the eyepiece. Since the IBM PC Camera's plastic snout got in the way, I removed it with a hacksaw, and blew the plastic dust off the lens with some canned compressed air. This allows a vast improvement. This shot was taken with the webcam hand-held:

Bee mouthparts, 40x, modified webcam

To simply image-taking, I added a mechanical adapter to the webcam. This was made from a 1.25" PVC pipe cap, with a hole drilled in the center. The cap was glued to the webcam with epoxy. An inner liner of corregated cardboard was attached with superglue. This allows the webcam to be slipped over the microscope eyepiece and remain stable:

Webcam modified to attach to microscope

The adapter makes the webcam much easier to use, since it keeps the camera aligned and centered over the eyepiece:

Modified webcam attached to microscope

Here's an image taken with the new setup. These are particles removed from melted snow with a magnet:

Rounded ferrous objects, 400x
These might be micrometeorites, but are more likely 'fly-ash' (small round particles that result when coal is burned).

While encouraging, looking at the image it now becomes clear that the resolution of the camera becomes a limiting factor.

Microscopy Links:

Webcam macrophotography
Using a webcam as a microscope
http://micro.magnet.fsu.edu/primer/
http://www.microscopy-uk.org.uk/index.html
Microscope Photography
Digital Microphotography
Molecular Expressions
MicroscopyU (Nikon)
Nikon's SmallWorld photomicrography contest
Olympus' BioScapes photomicrography contest
Mike Shaw's Tardigrade USA page