Digital Microscope - USB Microscopes

USB Microscopes

Digital microscopes range from inexpensive units costing from perhaps US$20 which connect to a computer via USB connector, to units costing tens of thousands of dollars. These advanced digital microscope systems usually are self contained, and do not require a computer.

Most of the cheaper microscopes which connect via USB have no stand, or a simple stand with clampable joints. They are essentially very simple webcams with small lenses and sensors—and can be used to view subjects which are not very close to the lens— mechanically arranged to allow focus at very close distances. Magnification is typically claimed to be user-adjustable from 10× to 200-400×.

Devices which connect to a computer require software to operate. Basic operation includes viewing the microscope image and recording "snapshots". More advanced functionality, possible even with simpler devices, includes recording moving images, time-lapse photography, measurement, image enhancement, annotation, etc. Many of the simpler units which connect to a computer use standard operating system facilities, and do not require device-specific drivers. A consequence of this is that many different microscope software packages can be used interchangeably with different microscopes, although such software may not support features unique to the more advanced devices. Basic operation may be possible with software included as part of computer operating systems—in Windows XP, images from microscopes which do not require special drivers can be viewed and recorded from "Scanners and Cameras" in Control Panel.

The more advanced digital microscope units have stands that hold the microscope and allow it to be racked up and down, similarly to standard optical microscopes. Calibrated movement in all three dimensions may be available. Resolution, image quality, and dynamic range vary with price. Systems with a lower number of megapixels have a higher frame rate (30fps) and faster processing. The faster processing can be seen when using functions like HDR (high dynamic range). In addition to general-purpose microscopes, instruments specialised for specific applications are produced. These units can have a magnification range up to 0-7000x, are usually all-in-one (don't require a computer), and can be portable. They also differ from the cheaper USB microscopes in not only the quality of the image but the quality of the system's construction giving these types of systems a longer lifetime.