Digital microscope

A digital microscope is a variation of a traditional optical microscope that uses optics and a digital camera to output an image to a monitor, sometimes by means of software running on a computer. A digital microscope often has its own in-built LED light source, and differs from an optical microscope in that there is no provision to observe the sample directly through an eyepiece. Since the image is focused on the digital circuit, the entire system is designed for the monitor image. The optics for the human eye are omitted. A digital microscope is a variation of a traditional optical microscope that uses optics and a digital camera to output an image to a monitor, sometimes by means of software running on a computer. A digital microscope often has its own in-built LED light source, and differs from an optical microscope in that there is no provision to observe the sample directly through an eyepiece. Since the image is focused on the digital circuit, the entire system is designed for the monitor image. The optics for the human eye are omitted. Digital microscopes can range from cheap USB digital microscopes to advanced industrial digital microscopes costing tens of thousands of dollars. The low price commercial microscopes normally omit the optics for illumination (for example Köhler illumination and phase contrast illumination) and are more akin to webcams with a macro lens. For information about stereo microscopes with a digital camera in research and development, see optical microscope. An early digital microscope was made by a company in Tokyo, Japan in 1986, which is now known as Hirox Co. LTD. It included a control box and a lens connected to a computer. The original connection to the computer was analog through an S-video connection. Over time that connection was changed to Firewire 800 to handle a large amount of digital information coming from the digital camera. Around 2005 they introduced advanced all-in-one units that did not require a computer, but had the monitor and computer built-in. Then in late 2015 they released a system that once again had the computer separate, but connected to the computer by USB 3.0, taking advantage of the speed and longevity of the USB connection. This system also was much more compacted than previous models with a reduction in the number of cables and physical size of the unit itself. The invention of the USB port resulted in a multitude of USB microscopes ranging in quality and magnification. They continue to fall in price, especially compared with traditional optical microscopes. They offer high-resolution images which are normally recorded directly to a computer, and which also use the computer power for their built-in LED light source. The resolution is directly related to the number of megapixels available on a specific model, from 1.3 MP, 2 MP, 5 MP and upwards. A primary difference between a stereo microscope and a digital microscope is the magnification. With a stereo microscope, the magnification is determined by multiplying the eyepiece magnification times the objective magnification. Since the digital microscope does not have an eyepiece, the magnification cannot be found using this method. Instead the magnification for a digital microscope was originally determined by how many times larger the sample was reproduced on a 15” monitor. While monitor sizes have changed, the physical size of the camera chip used has not. As a result magnification numbers and field of view are still the same as that original definition, regardless of the size of the monitor used. The average difference in magnification between an optical microscope and a digital microscope is about 40%. Thus the magnification number of a stereomicroscope is usually 40% less than the magnification number of a digital microscope. Since the digital microscope has the image projected directly on to the CCD camera, it is possible to have higher quality recorded images than with a stereo microscope. With the stereo microscope, the lenses are made for the optics of the eye. Attaching a CCD camera to a stereo microscope will result in an image that has compromises made for the eyepiece. Although the monitor image and recorded image may be of higher quality with the digital microscope, the application of the microscope may dictate which microscope is preferred.