How to Choose a Microscope

#1

Basics: Compound vs. Stereo

There are two basic types of optical light microscopes: compound (high power) and stereo (low power).

AmScope B100-MS Compound Microscope	AmScope SM-4T Stereo Microscope

If you need very high magnification to view the internal structures of cells, you would most likely use a compound microscope. Compound microscopes have not only very high magnification settings, but also have very high optical resolution (meaning, you can visualize very small features in an image with the objective lenses that come with these microscopes). Here is an example of what you would expect to see with a compound microscope:

Compound Microscope Field of View

If you need very high magnification to view the internal structures of cells, you would most likely use a compound microscope. Compound microscopes have not only very high magnification settings, but also have very high optical resolution (meaning, you can visualize very small features in an image with the objective lenses that come with these microscopes). Here is an example of what you would expect to see with a compound microscope:

Stereo Microscope Field of View

Each microscope type will be defined below in their respective section, however, a very simple way to determine what kind of microscope you need is by thinking of the sample type you want to view. Compound microscopes tend to require samples that you can pass light through to create an image, as the light comes from the bottom of the microscope up through the sample (transmitted illumination). Stereo microscopes, on the other hand, tend to work best with samples that you cannot pass light through, as they have upper light sources (reflected illumination) to shine down and bounce off of those samples to create an image.

As an example, you wouldn’t want to use a compound microscope with a transmitted light if you wanted to view a coin. A coin cannot pass light through it, so, you would be better off with a stereo microscope with a reflected light (as well as because you want a big field of view to see the whole coin). If you used a transmitted light, you’d get a black image in your microscope, as no light can pass through the coin.

Conversely, if you wanted to view a bacterial cell, you would want to use a compound microscope with a transmitted light, because a reflected light would wash your sample out, as it does not reflect enough light to make an image (as well as because you need the higher magnification to view such small details). You would probably see a very small outline of the cell, without much detail inside, if any at all, trying to use a stereo microscope with a reflected light with a slide that had a cell sample on it.

Slides for Mounting Samples to View with a Compound Microscope

Within each of these basic microscope types, however, there can be far more demanding requirements, and a variety of advanced microscopy methods or techniques exist within each base type of microscope. There exist some compound microscopes that use reflected light to view solid objects at very high magnifications, and some stereo microscopes with transmitted lights meant to view semi-opaque/semi-translucent samples, as an example. We will go over those in more specific sections, however; if you have a very specific or unique application, you may need a highly specialized microscope or special accessories to equip with one of our products. With our wide range of microscopes and accessories, we can help you configure an instrument for almost any application.

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1. Compound Darkfield Microscopy
2. Phase Contrast Microscopy
3. Fluorescence Microscopy

If unsure of what you specifically need, please don’t hesitate to contact our Customer Success team! We are more than happy to apply our knowledge and experience in years in the microscopy industry to help you succeed at whatever your application is with our equipment.

#2

Compound Microscopes

Compound microscopes are what most people visualize when they think about microscopes. They are available in monocular, binocular, and trinocular formats, which refers to the number of ocular tubes that the microscope has.

Monocular compound microscopes tend to be best for younger audiences that don’t quite fit a binocular compound microscope yet, or for individuals who only plan to use a camera. Binocular compound microscopes work best for teens to adults, as having both eyes open when viewing is much more comfortable than constantly closing one. Trinocular compound microscopes operate the same as binocular microscopes when viewing with the eyes, however, they have a dedicated port for a camera, allowing a user to mount the camera for use while viewing, or for easy storage of the camera accessory.

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1. Monocular Compound Microscope, SKU: M620
2. Binocular Compound Microscope, SKU: B120
3. Trinocular Compound Microscope, SKU: T120

Compound microscopes have a number of objectives (the lens closest to the object being viewed) of varying magnifications mounted in a rotating nosepiece. Typically the range of magnification on a compound microscope is between 40X and 1600X, although some are capable of higher or lower magnifications. Because only one objective is used at a time, and a single path of light is used, the viewer sees a two-dimensional image of the specimen. The objectives range from 2X to 100X, however, total magnification is the product of all magnifying elements in a path of light. We suggest shopping by total magnifications, as those are the end result settings that will ultimately be used to view your samples. Compound microscope total magnification is found by multiplying the objective magnification times the eyepiece magnification. For example, a 100X objective with a 10X eyepiece would give you a 1000X total magnification setting.

Objective Turret & Objective Lenses, 4X, 10X, 40X, & 100X, SKU: T490

Many compound microscopes also have a lens underneath the stage that focuses the light from the light source through the sample and into the objective lens, called a condenser. Some have simply a disc that controls the amount of light allowed through, called a disc diaphragm, while others have a slider with an iris and adjustable positioning, and even more have a completely replaceable condenser, allowing more advanced microscopy methods to be used, such as darkfield and phase contrast.

Darkfield Condenser Set, Oil & Dry, SKU: DK-SET-200-INF	Phase Contrast Condenser Kit, SKU: PCT200-INF

If you know what you’d like to do with a compound microscope, the following table can assist in getting you started with what you’re looking for with some common suggestions, or you can use the top navigation bar to click “Applications” to browse by solution, or “Compound” to browse by microscopy type/specifications. Otherwise, you can continue on to read about the other major type of microscopes—stereo microscopes.

#3

Stereo Microscopes

Unlike a compound microscope that offers a 2-dimensional image, stereo microscopes give the viewer an erect (upright and un-reversed), 3-dimensional image because they use two completely independent paths of light (one to each eyepiece) that are created using objectives that are focused at slightly offset positions in relation to the sample. The name “stereo” comes from the term “stereoscopic,” meaning, using two different angles of viewing to create an impression of depth and solidity.

Microchip View Under a Stereo Microscope

Because of this, true stereo microscopes only come in binocular and trinocular styles, however, a special type of stereo microscope called an “inspection” microscopes exists as well. These are very similar in nature to stereo microscopes, however, they only have a single ocular tube, so they provide a flat image view of larger, opaque objects, rather than a true stereoscopic view. We classify these here as they are capable of viewing the same sample types as stereo microscopes.

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1. Binocular Stereo Microscope on Table Stand, SKU: SM-1B-144S
2. Trinocular Stereo Microscope on Table Stand, SKU: SM-2T
3. SKU: H1000-96S-20MBI3

Stereo microscopes are particularly useful for biologists performing dissections, technicians repairing circuit boards, paleontologists cleaning and examining fossils, or anyone who needs to work with their hands or tools on small objects, but large enough to be seen or handled without the aid of a high power compound microscope. Thus, stereo microscopes have a very broad set of potential applications across many industries.

There are two main subdivisions of stereo microscopes at the most basic form, based on the magnification type—fixed power & zoom power. Fixed power stereo microscopes have a set number of fixed position objectives, and offer only the magnification options listed; nothing in between. They are best for their ease of use and ease of focusing, making younger audiences and amateurs great candidates for these kinds of stereo microscopes, but they lack the flexibility of other stereo microscope types.

On the other hand, zoom power stereo microscopes have much greater flexibility because the objective lenses can be moved closer or farther from the sample within the microscope. This allows a range of magnification options to be achieved within the maximum and minimum values the microscope provides, such as 7X through 45X. They require finer levels of refocusing when changing magnification values making it a bit harder to use, but offering far greater flexibility in terms of how much working distance, magnification, and field of view can be achieved.

Fixed Power Stereo Microscope, SKU: SE305R-A	Zoom Power Simul-Focal Stereo Microscope, SKU: SM-4TP

Most stereo microscopes are used at magnifications from 2X to 90X, but with the proper microscope and accessories, magnifications up to approaching 180X can be achieved, or even up to 225X! This is achieved using an accessory called a Barlow lens with or without different magnification eyepieces (15X, 20X, 25X, or even 30X eyepieces) that we also offer.

A Barlow lens is an auxiliary lens that is attached to the end of a stereo microscope’s objective, which alters the magnification range (or fixed settings available) on the microscope by a multiple of the Barlow lens’ power. This can work for both increasing or decreasing the magnification, which will either decrease the field of view and working distance by magnifying the image, or increase the field of view and working distance by reducing the magnification of the image, respectively.

These properties have an inverse relationship, meaning, the more magnification one uses, the smaller the field of view will be, and the closer the microscope lens needs to be to the sample to focus (which means less space to use tools, called working distance or focal distance). Vice versa, the less magnification being used, the larger the field of view and working distance are. In this case, more is not always better! You want the right magnification for your sample based on your needs.

Also, this means that any SM- (7X-45X base magnification) or ZM- (6.7X-45X base magnification) series stereo microscope package can be altered by adding in any number of Barlow lenses that are offer to expand the range out. Just like compound microscopes, total magnification is a product of all magnifying elements, so a stereo microscope may have 10X eyepieces, and an objective set to 1.0X, which would give you 10X total magnification. A 2.0X Barlow lens could take that up to 20X, while a 0.5X Barlow lens could take that down to 5X, depending on which is installed (not both, as stacking will throw the focus of the objectives off, while cancelling each other out in terms of magnification modification).

The great part about stereo microscopes is that they are very modular in nature, so whether you want a pre-made package designed by us, or to customize your own setup based on your preferences, we can accommodate your needs! Have a large sample that you need to view multiple areas of? We have a boom stand or articulating arm stand option for you. Need a simple table stand with a large area for dissection? No problem, we have that too.If you know what you’d like to do with a stereo microscope or an inspection microscope, the following table can assist in getting you started with what you’re looking for with some common suggestions. Alternatively, you can use the top navigation bar to click “Applications” to browse by solution, or “Stereo” to browse by microscopy type/specifications. Otherwise, you can continue on to read about the taking an optical light microscope of both base microscope types and converting it to a digital microscope that you can take digital images or record video by adding a camera.If you’re unsure of what you need, or have questions about creating your own setup, give our Customer Success team send us an email. Our friendly and helpful agents will be happy to assist you in getting the right microscope and accessories for you.

#4

Microphotography: Cameras & Videos

For many applications, the ability to capture, display, and preserve specimen images is of equal or greater importance than actually viewing the specimen through the eyepieces. Microphotography (35mm and other chemical formats) has been a common option on microscopes for decades, but the recent development of relatively inexpensive CCD (charged couple device) video and digital cameras has greatly increased both the popularity and flexibility of microscope imaging.

Instead of clicking through slides during a lecture, university professors can now display real-time video images on projection televisions; petroleum geologists can e-mail images of core samples to their laboratories from remote locations around the world; oncologists can refer to CD or on-line catalogues of cell images to help them make faster and more accurate diagnoses.There are many different methods for capturing, displaying, and recording microscope images, and each has its own advantages and disadvantages. Some are USB cameras that require a computer to interface with, but, include advanced software capable of measurements and other forms of data analysis, while others are HDMI cameras with on-board storage for easy use in training or web uploading, directly to a monitor, without the need of a cumbersome PC. Others have high sensitivity to light, providing better results in low light photography, such as darkfield or fluorescent microscopy methods, whereas others are more specialized for different applications, such as with cooling systems to minimize noise for extremely high sensor performance.It would be impossible to cover all of these options here, but one basic piece of information will be important in selecting your microscope. While it is possible to mount a camera on a monocular or binocular microscope, it is generally far better to use a trinocular microscope designed for camera work. Trinocular models have two eyepieces for normal viewing, plus a third "phototube" on which you can mount a camera without interfering with the normal operation of the microscope—many of them which have their own adjustments to help compensate for any focal differences between the eyepiece path of light and the camera’s path of light (called “simul-focal” trinocular microscopes”).

Trinocular microscopes are ideal for photo, digital or video applications.We also carry adapters for DSLR/SLR camera bodies, if you’d prefer to use your own body with a microscope—particularly useful for owners of high end cameras or professional photographers.If you know what you’d like to do with your camera, the following table can assist in getting you started with what you’re looking for with some common suggestions, or you can use the top navigation bar to click “Cameras” to browse by camera type/specifications.

Why Buy From Us?

Depending upon your application, additional components may be required for your microscope. Our friendly Customer Success team can assist you in choosing the appropriate items required by emailing us.Why Buy From Us?

• All of our microscopes come with a five year warranty!
• World-class Customer Success Team available via email, or live chat to support you!
• Free shipping within the UK
• Best price, guaranteed!
• Flexible shopping experience!