For a basic understanding; there are 3 different variations of microscopes:
Compound Microscopes (Upright & Inverted)
These types can be subdivided further. They stem from these 3 variants:
The best place to start for identifying the correct microscope is with your samples and specimens. From this, a rough magnification range can be established and therefore whether a “high magnification” (typically a compound microscope) or “low magnification” (typically a stereo microscope) is required.
High magnification/compound microscopes will usually offer between 40X – 1000X magnification, which is suitable for studying cells, bacteria, pond water etc.
Low magnification/stereo microscopes typically offer 7X – 45X magnification. These are used for applications such as PCB inspection, jewellery and diamond inspection, engraving, studying insects, etc.
There are a three different types of stereo microscope; single magnification, dual magnification and zoom magnification.
Some applications will require a set magnification with no requirement for additional magnification – stone setting for example which typically requires 10X or 20X and therefore a single magnification stereo microscope is usually most suitable.
Other applications will require a number of low magnifications to fully inspect and quality control – PCB and PCB track inspections for example which typically require 20X and 40X magnifications. Dual magnification or stereo zoom microsocpes are most suited to these applications.
On both stereo microscopes and compound microscopes, the magnification is worked out by mulitplying the power of the objective by the power of the eyepiece. If you have a 5X objective and 10X eyepiece, this would offer 50X magnification.
The next point to consider is time spent using the microscope.
For most, a binocular headed microscope (with two eyepieces) is more comfortable to use for longer periods of time. Monocular headed microscopes (with only one eyepiece) are useful for quick inspections, are frequently seen in schools and also make popular gifts for children.
At this point it is also worth considering whether a camera attachment would be beneficial now, or later in the future. Many microscopes do not allow retro-fitting of dedicated camera ports (trinocular ports or photoports) so if you are likely to want to attach a camera at any point in the future, it is recommended that a trinocular headed microsocpe be purchased from the start to avoid the additional expense later down the line. It is possible to bypass this by using an eyepiece camera that slots into the eyepiece tube in replace of one of the eyepieces, however this does have its limitations (one example being that you can’t view down the eyepieces at the same time as using the camera).
Budget and Quality – these two final considerations often go hand in hand. Cheaper microscopes will have cheaper parts. The best advice is to buy from a reputable seller who can offer support and warranties for the products; if they cannot offer these, keep looking!
You will notice that until this point, digital microscopes have not made an appearance. They will cater for both high and low magnification requirements. A digital microscope is essentially a combination of a microscope and a camera – either literally an optical microscope combined with a camera to convert it into a digital microscope, or a microscope with a built-in camera system.
As mentioned in ‘Budget and Quality’, with very cheap digital microscopes be sure to check the warranties and support offered, as this is more critical with software driven digital microscopes, especially the regular update of drivers (which should available free of charge!).
These are just a few notes which hopefully help guide you through the many different types of microscopes.
Of course, if you’re still unsure, please give us a call or email and we will be happy to help!