There are a surprising number of so-called “Pocket Microscopes” available today. I even remember pocket microscopes advertised in the pages of comic books back when I was a kid. And at that time, comic books were not targeting adult readers. There were pocket telescopes as well, and combination pocket microscopes and telescopes. Also radio-pens, X-Ray glasses, a nuclear submarine (for only $6.98) and of course Sea Monkeys.

What has changed with today’s pocket microscopes is three-fold. First, our optical expectations have increased meaning if the magnified image is not razor-sharp, we’ll keep looking (pardon the pun).

Second, the advent of LED lighting makes anything worth illuminating worth illuminating. So any pocket microscope worth its sodium chloride must have an efficient and effective illumination system. And third, the micro optical microscope must be affordable. 

Some would add a fourth dimension in that the optics of the pocket microscope must dovetail with the technology of the present, usually the smartphone camera.

In the case of the Carson MicroMini 20x Pocket Microscope, all conditions are met, and the price makes a classroom set within financial reach. 

I have always had an affinity for small magnifying optics, and  enjoy putting them in the hands of students because even the most basic and low power magnifiers are magical windows into a whole universe right in front of them. An optical problem arises when the magnification goes up because the the depth of field thins and the more light is needed for the same visual brightness as a lower magnification.

Further, the quality of the optics play a larger roll as the magnification increases. Most traditional looking magnification glasses are about 2x. Smaller ones, maybe 5x. Jeweler’s loupes, those cute little metal-cased lenses often worn around the neck, are usually 10x, and some in the same form factor but smaller reach out to 20x. Using a loupe requires a practiced dance between holding the tool a centimeter from one’s eyeball and balancing the object’s distance from the loupe and the loupe from your eye in order to focus. It truly is a skill.

So handing a 20x magnifier to a student does not instantly cause scientific enthusiasm. Instead, the use of the magnifier is a chore that has little immediate return. However, if the 20x magnifier could be placed directly on the subject allowing a flush focus, and a bright light illuminates the subject causing a deeper depth of focus and contrast, the wonderful world of the microscopic is now easily accessible.

The Carson MicroMini 20x Pocket Microscope is a small package not much bigger or smaller than a ping pong ball. The feature-filled Carson 20x Pocket Microscope has an eyepiece, focus wheel, objective lens, LED white light, and LED UV light. There is also a keyring chain. At first I used the keyring to hold onto the scope, but found that a little cumbersome so I removed it.

The surface of the Carson MicroMini 20x Pocket Microscope is a little slippery so I attached a little texture tape to the grip surface. That tape also solved another thing I noticed in that I routinely pushed the UV light button by accident. While those modifications certainly are not needed, it does make a noticeable difference.

A large ribbed focus wheel covers much of one side of the Carson MicroMini 20x Pocket Microscope allowing a full 260 degrees of its circle. This access to the focus wheel provides ease of use from many different hand positions, and the low friction spin of the wheel keeps the Carson MicroMini 20x Pocket Microscope on target as fine adjustments are made. The focus is designed for flush viewing with the Carson MicroMini 20x Pocket Microscope on or against the subject to be viewed. If the subject is an irregular 3-D shape, some finesse will be needed both acquire and retain focus.

The field of view of the Carson MicroMini 20x Pocket Microscope is about six millimeters across. The focusing is designed to maximize a flat field with the magnifiers base flush with the subject so turning the wheel is a fine focus of that plane. It does not allow for using the Carson MicroMini 20x Pocket Microscope above or away from the subject.

The Carson MicroMini 20x Pocket Microscope works well in tandem with a smartphone camera. The flush focus aspect of the Carson MicroMini 20x Pocket Microscope keeps the system stable, and by adding a little zoom to the camera, you can fill up the frame with what the Carson MicroMini 20x Pocket Microscope sees.

Three battery-powered lighting options are possible with the Carson MicroMini 20x Pocket Microscope. A near-lens white LED, an offset white LED and an offset ultraviolet LED. Most lighting will be with then near-lens LED. It provides the most and most direct lighting. However sometimes it is too much, especially on reflective subjects, or where some shadow texture is needed. But mostly the second light makes a good short-range general purpose flashlight. And the UV light adds another visual dimension to those things that glow under ultraviolet which as Sciencenotes.org points out, is quite a few things.

The Carson MicroMini 20x Pocket Microscope is a great magnification solution for the classroom and field, as well as adding microscopic superpowers to a smartphone. The Carson MicroMini 20x Pocket Microscope comes in three colors, weighs about one ounce (~30 grams), and sells for $13 which is a dollar less than a pair of nuclear submarines!