When choosing a microscope, there are many questions to ask: who is it for? What is the intended application? What is your price range? What kind of magnification are you looking for?
There are three basic things you need to know:
First, an optical microscope has two sources of magnification. The primary source is via the objective lens and the secondary source is via the eyepiece lens. The magnification of an image is the number of times the image appears larger than the object. The magnifying power of a microscope is that of the two lenses multiplied together.
For example: Standard eyepieces have a power of 10x. When using a 40x objective lens, the total magnification would be 400x.
Secondly, avoid falling into the trap of being attracted by high levels of magnification. A significant portion of the world’s microscope applications require magnification levels of less than 60x!
In the world of microscopy, there are two basic types of optical light microscopes: compound and stereo. Compound microscopes tend to have a greater power, or magnification than a stereo microscope. So, which one would you need?
If you are new to microscopy or are looking for a child’s first microscope, it is a good idea to start off with a beginner’s compound microscope. These typically retail around the £60-£90 price point and have reasonable objective lenses. Prepared Slides are an excellent companion for these as you can immediately begin studying a whole host of different specimens. Alternatively, we do have a series of kits designed to help you create your own slides.
If you would rather look at larger objects in detail, a stereo microscope would be ideal. These are designed for viewing whole objects such as fossils, minerals, insects, stamps, and coins and have a considerably lower magnification than a compound microscope. These typically range between 15x and 30x. The two eyepieces of a stereo microscope provide greater depth perception than a compound microscope does, giving you a three-dimensional view.
Furthermore, stereo microscopes come into their own in the field of manufacturing when the work area is only a few millimetres in size. These are particularly useful when soldering electrical connections or assembling medical products such as pacemakers or artificial heart valves.
If you would like to study cells and cell structure, a magnification of 400x is widely regarded as the bare minimum magnification needed. Conversely, dust particles, insect parts, hair and other objects are much better observed under magnifications of 40x and 100x. This is where a compound microscope comes into its own.
The reason for this is that such specimens require higher powers of magnification in order to see the minute details. Typically, a compound microscope has three to five objective lenses that range from 4x-100x. Compound microscopes are also integrated systems in the sense that the microscope body and base form a complete unit.
The other thing to bear in mind is the stage for the slides. The function of the stage is to provide a stable platform to mount the microscope slide to allow for easy viewing. Mechanical stages allow for fine-tune adjustment of the slide along the X and Y axis. This is especially useful if you are viewing samples such as plant cells without having to manually manipulate the slide and risk losing the section you are observing!
Finally, it is useful to ensure that the objectives are DIN compatible. Most of our Compound Microscopes feature DIN rated objective lenses. This allows for the objective lenses to be interchangeable from one microscope to another, which is especially helpful should you accidentally lose or damage one! Rather than having to buy another microscope, you can easily replace the lens.