Friday, March 29, 2013

More on Darkfield Microscopy

Darkfield microscopy requires a special stand containing a reflective mirror and light shielding plate at a specific angle. The inverted hollow cone is projective of the desired image at an oblique angle. This process is the same for both stereo microscopes and standard compound microscopes. 

Good specimens for darkfield microscopy are those close in value to their background images. Small aquatic organisms and cells are ideal for such microscopic lighting technique. Specimens preferred for use with brightfield lighting are not recommended. Other ideal specimens for darkfield microscopy under a stereo microscope include bones, fibers, yeast, and hairs.

Illumination from brightfield lighting involves blocking out central light rays along the central axis. Blocking these rays allows for only oblique angled rays to strike the specimen resulting in a hollowed cone illumination of the desired specimen.

In darkfield lighting, contrast is greatly enhanced by the lighting technique at hand. Highly oblique light rays, diffracted by the specimen and yielding first, second, and higher diffracted orders at the rear focal plane of the objective, proceed onto the image plane where they interfere with one another to produce an image of the specimen.

We recommend our 1600X Darkfield Compound 9MP Digital Siedentopf PLAN Microscope
with 4 PLAN objectives and darkfield condenser. 

Monday, March 25, 2013

Featured Product: Trinocular Zoom Stereo Microscope

This week we are featuring one of our top selling microscopes..
Our 7X-45X Trinocular Zoom Stereo Microscope with Dual Lights includes a 5.0 Megapixel Camera and software compatible with Windows XP/Vista/7. The included software can be used to make measurements on your PC. The 2592 X 1944 pixels from the USB digital camera can capture both still and live images on your computer, making this microscope ideal for live specimen analysis and laboratory observations.

This microscope includes an adjustable barlow lens that can extend the working distance up to 6.25" long and the field of view to be as wide as 2.38" long. This microscope also includes dual halogen lights with adjustable intensities.  This microscope is ideal for biological research labs, engravers, watchmakers, gemologists, jewelers, collectors, and those in electronic related industries. 

This microscope is also easily customizable as well. You can add a darkfield stage for darkfield observations. A boom stand and gooseneck light for a larger work space. You can also add different eyepieces, lights, and cameras. The possibilities are endless with the Trinocular Zoom Stereo Microscope. 

Shop Microscope now: Click here

Wednesday, March 20, 2013

Microscopes for Homeschoolers

Microscopes are beneficial for students who are homeschooled because it enables them to have the same type of exposure to science and experiments as those enrolled in public education institutions. 

The first thing you need to decide is what kind of observations your child/student will be expected to view and what kind of experiments he/she will partake in during the school year. Next you will need to decide if it is best to purchase a compound or stereo microscope. 

A compound microscope is only useful got looking at slides, which may get rather boring for students, slides must be purchased or made at home, which can be tedious and time consuming. A stereo microscope will enable your student to view live specimens, 3-D objects, and some slide use. 

For normal observations, you probably will not need a microscope with a magnification higher than 400X. 400X magnification is generally the highest level students use in most high school courses. 

Experiment Ideas:
If you decide to purchase a stereo microscope you can fill a small plastic tray with pond water and have them look through the side of the container with the microscope. If you decide to purchase a compound microscope you can purchase plain slides and cover slips and make your own slides out of vegetable peels, plants, and other transparent 3-D objects. 

Tuesday, March 19, 2013

Polarizing Microscopes Explained

A polarizing microscope is a microscope that is mainly used in geological studies to study geological specimens. For this reason, it is also known as a petrographic microscope. It is used in other scientific fields such as medicine and biology as well.

Polarizing microscopes are built like regular optical microscope, but are fitted with some extra features. Unlike regular microscopes which use normal light, a polarizing microscope uses polarized light to study specimens. In polarized light, the light waves vibrate in one direction; in normal light, the light waves vibrate in random directions.

Geological specimens ground into thin sections for study. The specimen to be studied is placed on a slide on a rotatable specimen stage. The specimen is then illuminated by a light source under the specimen stage.

Product Features Include:
  • Capable of bright field, and polarized light observation
  • Infinity optical system, Kohler transmitted illumination
  • 5 plan infinity strain free achromatic objectives
  • Polarizer
  • Analyzer
  • Bertrand lens
  • Compensator plates
  • 1.3 MP digital camera  

Monday, March 18, 2013

Microscope Glossary

The following terms have been simplified and defined in order to enhance your understanding of the use and functions of the various components of both stereo and compound microscopes. 

Arm:  The part of the microscope that connects the tube to the base.  When carrying a microscope, grab the arm with one hand and place your other hand under the base.
Articulated Arm:  A type of stand that holds a microscope body.  The stand clamps to a table and has a variety of motion in three dimensions. 
Base:  The bottom support of the microscope.
Binocular Head:  A microscope head with two eyepiece lenses, one for each eye.  Body:  This term is used mostly with the low power stereo microscopes and it is the basic heart of the microscope without any type of stand or illuminators.  It usually includes the eyepiece and objective lenses but not the focusing block.
C-mount:  This is an adapter used with various types of video cameras.  Usually, you unscrew the lens from the camera and screw in the adapter.  The adapter then connects to the trinocular port on the microscope.
Coarse Focus:  This is the rough focus knob on the microscope.  You use it to move the objective lenses toward or away from the specimen (see fine focus).
Coaxial Focus:  A focusing system that has both the coarse and fine focusing knobs mounted on the same axis.  Usually the coarse knob is larger and on the outside and the fine knob is smaller and on the inside.  On some coaxial systems, the fine adjustment is calibrated, allowing differential measurements to be recorded.
Condenser Lens:  A lens mounted in or below the stage whose purpose is to focus or condense the light onto the specimen.   The higher power objective lenses have very tiny diameters and require concentrated light to work properly.  By using a condenser lens you will increase the Illumination and resolution.  Condenser lenses are not required on low power microscopes.
Contrast Plate:  A circular opaque plate placed on the stage of a low power microscope.  One side is white, the other is black.  It can be flipped around depending on the coloration of your specimen.
Cover Slip:  A very thin square piece of glass or plastic placed over the specimen on a microscope slide.  When used with liquid samples, it flattens out the liquid and assists with single plane focusing.
Diaphragm:  Generally a five hole disc placed under the stage on a high power microscope.  Each hole is of a different diameter.  By turning it, you can vary the amount of light passing through the stage opening.  This will help to properly illuminate the specimen and increase contrast and resolution.  The diaphragm is most useful at the higher powers.
Dual Head:  A microscope with a single eyepiece lens coming out one side and an additional single eyepiece tube coming either off the top or from the opposite side.  Dual heads are used so that a teacher can verify what a student is seeing or can be used for video or camera work.  It is not recommended that two students do a lab sharing a single dual microscope as it will get to be uncomfortable for the student using the top eyepiece.
Eyepiece Lens:  The lens at the top of the microscope that you look into.  They are usually 10X but also are available in 5X, 15X and 20X.  Widefield lenses have a large diameter and show a wide area of the field of view. 
Fine Focus:  This is the knob used to fine tune the focus on the specimen.  It is also used to focus on various parts of the specimen.  Generally one uses the coarse focus first to get close then moves to the fine focus knob for fine tuning. 
Field of View:  Sometimes abbreviated "FOV", it is the diameter of the circle of light that you see when looking into a microscope.  As the power gets greater, the field of view gets smaller.  You can measure this by placing a clear metric ruler on the stage and counting the millimeters from one side to the other.  Typically you will see about 4.5mm at 40X, 1.8mm at 100X, 0.45mm at 400X and 0.18mm at 1000X.  See micrometer.
Fixed Arm:  A type of stand used with low power microscopes.  The arm and body are integral parts of the microscope and connected solidly to the base. 
Focus:  A means of moving the specimen closer or further away from the objective lens to render a sharp image.  On some microscopes, the stage moves and on others, the tube moves.  Rack and pinion focusing is the most popular and durable type.
Head:  The upper part of the microscope that contains the eyepiece tube and prisms.  A monocular head has one eyepiece, a binocular has two (one for each eye), a dual head has two but they are not together, and a trinocular head has three, one which is generally used for a camera connection.
Illuminator:  A light source mounted under the stage.  Three types of light are commonly used:  Tungsten, Fluorescent and Halogen.  Tungsten is the least expensive and most common.  Fluorescent is bright, white and runs cool and Halogen is very bright and white but gives off heat like tungsten.
Immersion Oil:  A special oil used in microscopy with only the 100X objective lens (usually at 1000X total power).  A drop is placed upon the cover slip and the objective is lowered until it just touches the drop.  Once brought into focus, the oil acts as a bridge between the glass slide and the glass in the lens. 
Inclination Joint:  Where the arm connects to the base, there may be a pin.  If so, you can place one hand on the base and with the other grab the arm and rotate it back.  It will tilt your microscope back for more comfortable viewing.  One drawback of tilting it back is that wet samples will run off the slide.
Mechanical Stage:  A mechanical way to move the slide around on your stage.  It consists of a slide holder and two knobs.  Turn one knob and the slide moves toward or away from you.  Turn the other knob and the slide moves left and right.  Since everything is upside down on a (high power) microscope it takes some getting used to but it is very convenient to have one especially when observing moving specimens like protozoans or other pond water critters.  Microscopes either have the bolt on mechanical stage that can be added (to many models) at any time or the integral mechanical stage that comes built in to the microscope. 
Micrometer:  Also called a micron it is the metric linear measurement used in microscopy.  There are 1000 microns in a millimeter.  If something is 1.8mm long then it can also be expressed as 1,800 microns long.
Mirror:  Allows you to direct ambient light up through the hole in the stage and illuminate the specimen.
Monocular Head:  A microscope head with a single eyepiece lens.
Nose piece:  The part of the microscope that holds the objective lenses also called a revolving nose piece or turret.
Objective Lens:  The lens closest to the object.  In a stereo microscope there are objective pairs, one lens for each eyepiece lens.  This gives the 3-D effect.  On a high power binocular model there is still only one objective lens so no stereo vision.
Oil Immersion Lens:  An objective lens designed to work with a drop of special oil placed between it and the slide.  With oil, an increase in resolution will be noticed.    Also, see "Immersion Oil" above.
Rack Stop:  Usually set at the factory, the rack stop keeps you from cranking the objective lenses too far down (damaging something).  If you are using a very thin slide, you may find that you can't get the high power objective lens close enough to the slide to focus.  Here you can either adjust the rack stop or place a thin glass slide under your original slide, making it closer to the lens.
Resolution:  The ability of a lens system to show fine details of the object being observed.
Ring Light:  An independent light that usually connects to the microscope body and gives off a ring of light. 
Semi-Plan Lenses:  Lenses are never perfect.  If you were looking at something perfectly flat, you might find that much of the center part of your field of view is in focus but out on the edges it is fuzzy and a bit out of focus.  Semi-plan lenses improve this deficiency by showing sharper images and less aberrations in the perimeter of the field of view.  They are better than standard achromatic lenses but cost quite a bit more.
Slide:  A flat glass or plastic rectangular plate that the specimen is placed on.  It may have a depression or well to hold a few drops of liquid.
Slip Clutch:  When students bring the focus all the way up or down and continue to try turning the knob, damage to the focusing system can occur if there wasn't a slip clutch.  It is a mechanical device that protects the gears of the microscope.
Stage:  The flat plate where the slides are placed for observation.
Stage Clips:  Clips on the stage used to hold the slide in place.
Stage Plate:  On a low power microscope, there is a frosted circular glass plate that fits in over the lower illuminator.  This is called the stage plate.  See also contrast plate.
Stand:  On a low power microscope, the type of connection between the microscope body and the base.  There are three main types:  the post, the fixed arm and the universal boom stand. 
T-mount:  A type of adapter used to mate still cameras to microscopes
Tension Adjustment:  This is an adjustment of the focusing mechanism that is made at the factory.  It is set so that the instrument is easy to focus but also tight enough so that the stage doesn't drift when you are not focusing. Stage drift is caused by the weight of the stage automatically unfocusing the microscope.
Trinocular Head:  Available on both high and low power microscopes, tri heads have two eyepiece lenses and a third port at the top for a camera.  Some microscopes give you the option of sending all the light to the tri port. On some stereo tri heads with dual power, the tri port transmits the image through the set of lenses not being used by the stereo eyepieces.
Widefield eyepiece lenses:  These are wide diameter glass eyepiece lenses.  They offer the greatest field of view when looking at specimens. 
X:  Times as in 200X or two hundred times magnification.  The magnification of a microscope is determined by multiplying the power of the eyepiece lens by the power of the corresponding objective lens.

Sunday, March 17, 2013

Microscopes For Students

Buying a microscope can sometimes seem like a difficult challenge because there are so many variations of microscopes out on the market today. It is important to be mindful of your intended use and level of expertise before purchasing a student microscope. 

You don't have to be an expert to select an adequate microscope suitable for classroom and homework use. The following feature list will help you narrow down your search and give you an idea of what to look for when purchasing a student microscope.

1. Dual Focusing- Look for coarse and fine focus for a precise focal point
2. A Built in Light- Optimizes viewing of the specimen under the microscope
3. A Mechanical Stage- Allows you to move the slide horizontally and vertically to have a better look at the specimen
4. Binocular Eyepieces- to ensure you are not straining one eye trying to focus on a specimen. 

We recommend starting out with a compound microscope which can be used at higher magnifications and observe small transparent specimens. This is ideal for lab work and science courses. 

Product Recommendation:
Lab Binocular Biological Compound Microscope 40X-1600X w Halogen Light $229.99

Tuesday, March 12, 2013

Compound Microscopes

What's the difference between a compound and stereo microscope? Many beginners are unsure of which model to purchase due to their lack of knowledge about both types of microscopes. This article will touch on the differences between a compound microscope and a stereo microscope and discuss the main purposes of a compound microscope.

The main difference between a compound and stereo microscope are that a compound microscope is ideal for transparent specimens and a stereo microscope is ideal for denser specimens such as gems, rocks, and minerals. Compound microscopes are higher in power than a stereo microscope and have higher magnification power. Compound microscopes are suitable for use in laboratories, hospitals, and schools. 

Compound microscopes are traditional microscopes that are designed with a compound lens system. A compound microscope typically has a rotatable lens system with various objective powers. Compound microscopes are ideal for high powered specimens due to their bottom light source and need for the specimen to be on a slide. Visual observations with a compound microscope are typically two dimensional and can be observed in a number of microscopy techniques depending on the lighting method used. 

For more information visit our website at

Monday, March 11, 2013

Advantages of Purchasing a Digital Microscope

Digital microscopes have helped simplify scientific observation and research in modern times. A digital microscope is generally a compound or stereo microscope with a built in digital camera that is compatible with a PC or TV. The images are projected onto the monitor and can even be saved as JPEG and video files on a computer. These data saving options are great for extensive research and referencing. 

The main advantage of a digital microscope, is that is is suitable for educational purposes. Many students in various fields such as biology, chemistry, and medicine can view specimens from a digital camera hooked up to their home computer. This is a great time saver and also ensures that research results are more accurate because they can cross-reference their research findings with live and still images.  Students can recall the image later to describe it in greater detail for an observation report. 

Another advantage to using a digital microscope, is that it allows for researchers and students to print images from their microscope and use them for projects and research both in the lab and in the classroom. 

For students we recommend our Digital Compound Microscope with 1.3 MP Camera. This a great starter microscope for students at a freshman and sophomore level. 
For professionals, we recommend our Trinocular Metallurgic Microscope with 2.0 MP Camera. This microscope is ideal for metallurgical and electronic industries. 

Sunday, March 10, 2013

7 Tips for Purchasing a Microscope

1. Avoid Purchasing from a Chain Retailer: It is not advised you purchase a microscope from a nature store and/or toy store. These are almost always poor quality and are not intended for actual professional grade use and observations. Try to get a microscope at a student or professional level. 
2. Try to Avoid Plastic Parts : It is ok if some digital microscopes have plastic screens and attachments but do try to refrain from purchasing a microscope with mainly plastic parts. Especially a plastic frame, eyepiece, and stage. 
3. Try to Keep your budget above $200.00 USD: Generally speaking, $200-$400 USD is a fair price for a student microscope or beginner microscope. Look for frames, focusing systems, and stands to be made of quality materials.
4. Look for Separate Course and Fine Focus Features: Look for a microscope with both coarse and fine focus settings, this will provide better clarity and image quality when using an attachable USB digital camera hooked up to a PC or TV.
5. Look for Halogen Lighting: Halogen lighting is ideal for its clarity and noticeable brightness. 

6. Look for Glass Lenses: Glass plan optics are of greater quality and are suitable for professional and lab use. Semi-plan lenses are idea for schools, students, and hobbyists.
7. Consider a Mechanical Stage: A mechanical stage allows for easier movability and can handle a larger project and/or specimen. Mechanical stages are essential for medical and laboratory microscope work. 

A great beginner microscope at a reasonable price is our Industrial Inspection Monocular Microscope Zoom 7x-90x.

Product Features Include:

  • Height adjustable holder ready for attaching ring light
  • High definition images
  • High quality eyepieces
  • Ready to connect to USB digital camera
  • Zoom lenses 7x~90x, crystal clear at any point
  • Long working distance allow enough lighting options
  • Sharp images over a wide field view
  • Metal stand and framework
  • Product GS and CE approved
  • Manufacturer in business 30+ years

Monday, March 4, 2013

Phase Contrast Microscopy

Phase contrast microscopy is a technique that coverts phase shifts in light passing a semi-transparent specimens. Phase contrast microscopy is particularly useful for biology studies and research because it reveals molecular cell structures that may not be detectable using a bright field method. Phase changes are made possible with the separation of light from the specimen. 

Phase contrast microscopy makes it possible for biologists to study living cells and cell division as well as live video recording of living organisms. It is recommended to use a microscope with both bright field and phase contrast options, preferably with a digital camera for optimal viewing of both still and live specimens. 

Our 1600X Phase Contrast Siedentopf 3MP Digital Compound Microscope is ideal for biology students, laboratories  and researchers alike. This microscope has three viewing options along with a PC compatible software that can be used for measurements with no slide staining required.

The phase contrast kit on this microscope comes with a(n):

  • phase kit condenser
  • telescopic eyepiece
  • four plain objectives
  • eight levels of magnification

Sunday, March 3, 2013

Jewel Gem Microscopes

Jewel Gem microscopes are utilized by gemologists and gem enthusiasts alike. Although correct filters and a quality refractive index fluids will allow you to identify a gemstone by their internal characteristics and optic characteristics.

A microscope useful for gemology will need to have the following properties..

  • 10X-80X Magnification
  • Adjustable Illumination
  • Darkfield Lighting Option
  • Zooming Objective Lens
  • Widefield Eyepieces

Other additional features that are useful to gem identification include LED lights and gooseneck lighting for maximum work space utilization. 

Our professional gem jewel darkfield stereo microscope is ideal for commercial gemologists.Click here to view product.