What is Stereo Microscope
A stereo microscope is an optical microscope that provides a three-dimensional view of a specimen. It is also known by other names such as dissecting microscope and stereo zoom microscope. Dissecting microscope parts include separate objective lenses and eyepieces. As a result, you have two separate optical paths for each eye. The slightly different angling views to the left and right eyes produce a three-dimensional visual. Because it gives the three-dimensional view it is also called as the dissecting microscope.
The Characteristics of a Stereo Microscope
– Two separate objectives
– Two separate optical paths
– Uses the light reflected from the object
– Typical magnification range between 10x and 50x
– Three-dimensional images
How Do Stereo Microscopes Work?
Parts of a Stereo Microscope
Every component of the stereo microscope has its own function. The parts included with this type of microscope can vary greatly depending on the configuration and uses it will serve. Each part of a stereo microscope is labeled in the diagram below. This example is a typical classroom type stereo microscope with plain stand.
Stereo Head: This is the moveable top portion of the microscope and the stereo head holds the two adjustable eyepieces.
Ocular Lens: These are the eyepieces through which the viewer looks at the specimen. The eyepieces are typically set at 10x magnification. It is also possible to upgrade to a higher magnification level.
Objective Lens: Stereo microscopes have two separate objectives, each one connecting to one of the eyepieces. The eyepiece and the objective lenses collectively determine the magnification of the microscope. They can have a fixed single objective, a rotating multiple lens turret or a zoom. It allows you to change the magnification levels depending on the applications.
Focus Knob: Stereo microscopes usually have one focus knob. Helps move the head of the microscope up and down to bring a sharp image of the object. Most dissecting microscopes have standard “rack and pinion” focusing. Rack is the track with teeth and pinion is the gear that rides on the teeth. The knob helps the pinion move along the rack.
Stage Plate: It is located directly under the objective lens. It is where the specimen is placed for viewing. Some stereo microscopes have reversible black and white stage plates to provide appropriate contrast with the object being viewed.
Illumination: Many microscopes have both top and bottom lighting. Some microscopes only have one source of illumination, top or bottom. The top lighting shines down on the specimen and reflects light off them. The bottom lighting transmits light up through the stage to show translucent specimens.
A stereo or a dissecting microscope uses reflected light from the object. It magnifies at a low power hence ideal for amplifying opaque objects. Since it uses light that naturally reflects from the specimen, it is helpful to examine solid or thick samples. The magnification of a stereo microscope ranges between 10x and 50x.
Additional supplementary/auxiliary lenses can be attached to increase or decrease magnification and adjust working distance based on the user’s needs. For instance, if a longer working distance is required than a lens of less than 1x is required: 0.3x, 0.5x, or 0.7x. An ocular lens or eyepiece can allow you to increase the total magnification of your microscope to 300x or higher.
Opaque objects like coins, fossils, mineral specimens, insects, flowers, etc. are visible under a dissecting microscope magnification. More advanced stereo microscopes can allow you to view electrical components and circuit boards. Dissecting vs Compound Microscope
A stereo or dissecting microscope is not the same as a compound microscope. Unlike the compound microscope in a stereo microscope, the image is upright and not upside down and backward. A compound microscope yields a single optical path resulting in the same image to both the left and right eye. A stereo microscope provides two optical paths for each eye resulting in a three-dimensional view.
A compound microscope helps to look at samples under magnifications as high as 40x to 1000x or more. Examples include the viewing of animal or plant cells, blood counts, chromosomes, and bacteria. A stereo microscope also referred to as stereo zoom microscope uses low magnification and it can be either fixed magnifications (1 x and 3x or 2x and 4x) or continuous zoom magnification (0.7 x through 4.5x). It is used to view electronic components such as circuits, surface soldering, jewelry repair, fossil examination, insect or botanical dissections. When is a Stereo Microscope Used?
With a dissecting microscope one can work on a specimen in real-time while it is still being observed. Unlike the typical compound microscope, a dissecting microscope has a longer working distance that allows for dissecting objects or even perform microsurgery. Biologists can use these microscopes to do dissections, botanists to study plants, and pathologists to perform dermatological examinations.
Stereo microscope magnification helps sort and visualize peripheral surfaces in three-dimensions which allows for a thorough examination of objects. Stereo microscopes are used by technicians to repair circuit boards, paleontologists to clean and examine fossils, technicians to perform mud logging, specialists to analyze fabric and textiles, or anyone that wishes to view or work on small objects.
Stereo microscopes can be configured for any use. Various stands and mounts are available including boom stands, articulating or flex arms, plain stands, track stands, table mounts, and more. Additionally, microscope illuminators provide a more defined and illuminated view of specimens.