from being a trinocular microscope, the Amscope T490A-PCT has features for
three microscopy techniques, high magnification as well as advanced optics.
With a range of outstanding features in place, this microscope has also been designed
with increased functionality in mind. As such, it has a lot to offer the user.
The AmScope T490A-PCT microscope is a trinocular
microscope, which means that it comes with a trinocular viewing head. The vertical camera mount allows for
attachment of a 23mm or C-mount adapter. Here, the camera can simply be
attached and replaced when need be. This is a good feature in that the camera
is not built-in a manner that it cannot be replaced in the event that it is
damaged or needs to be upgraded.
Apart from the trinocular viewing head, the
microscope uses a Siedentopf binocular head which has a number of benefits. The
Siedentopf binocular head allows for interpupillary adjustment (55 to 75mm)
which allows for a variety of users to comfortably adjust the distance to the
length that suits them best. This can very easily be achieved by turning the
binocular part of the microscope outwards or inwards.
The viewing binocular
part of the microscope also has in place a scale between the two oculars that
can be used to set the interpupillary distance to the required distance for
use. Apart from ease of use, the Siedentopf binocular head also presents a big
advantage over the sliding head in that adjusting the interpupillary distance
does not affect focus. This is a very important feature particularly in
educational applications given that different students can adjust the
interpupillary distance to their desired length in order to observe the specimen
without affecting the focus. Therefore, all students observing the specimen are be able to view the same image quality.
The head of this microscope has also been
designed to ensure flexibility. This is made possible by the 30-degree vertical
inclination and flexible 360 degree rotation function of the Siedentopf head.
Whereas the fixed 30 degree vertical inclination is designed to reduce eye and
neck strain, the 360 degree rotation function is meant to help users enjoy a
comprehensive view without the need to turn or move the entire microscope in every direction.
The microscope comes with an interchangeable
pair of WF16x and WF10x eyepieces which with the objectives provide eight
levels of magnification (40x to 1600x).
As for the objectives, the Amscope
T490A-PCT comes with 4x, 10x, 40xS (spring), and 100xS (spring, oil) DIN
achromatic precision-ground optical-glass objectives, and 10x, 20x, 40x, and
100x phase-contrast plan objectives with phase-contrast turret.
advanced optical design is meant to ensure high quality images for the user.
Together with the eyepieces, the 4x, 10x, 40xS (spring), and 100xS (spring,
oil) DIN achromatic optical-glass objectives provide color correction for
magnified images. These being Plan objectives, they are meant to ensure
improved focus over the entire range of the viewing field and ultimately clear
Some of the other important features include:
Objectives mounted on a
turret for easy magnification changes
Spring loaded 40xS and
100xS to protect the lenses when they come in contact with a hard surface
1.25 NA Abbe condenser with
Graduated coaxial coarse
and fine focus with a focusing range of 1-3/16" (30mm) and fine-focus
divisions of 0.002mm (0.0000787") for making measurements
Focus knob tension control
to prevent the stage from drifting out of focus
The microscope uses a halogen bulb (6V/20W) as
the light source. However, the illumination system also comes with a rheostat
that serves to control the intensity of light. In addition, the Abbe condenser (1.25) with an iris diaphragm and a rack-and-pinion in place enable precise focus and light control.
The lower (transmitted, diascopic) brightfield,
darkfield and phase contrast illumination included in the microscope transmits
light up through the specimen for improved visibility of both transparent and translucent
It is worth noting that the AmScope T490A-PCT allows for three
types of microscopy techniques which include brightfield, darkfield and
phase-contrast. With brightfield illumination, the specimen gets to absorb
light, which results in a dark image on a background. This microscopy technique
is used for most of the disciplines that require microscopic investigation. It
is one of the most common methods used in such life sciences as microbiology
and bacteriology. As such, it is used to view and study fixed specimen and live
Darkfield illumination on the other hand
reflects light off the surface of the specimen. This results in a light image
on a dark background. As such, it is can be seen as the opposite of brightfield
This microscopy technique is particularly suitable for
unstained specimen given that contrast is already created when they are made to
appear bright against a dark background. The technique is largely used for viewing
and studying marine organisms, insects, hairs and yeast among many other
Lastly, phase-contrast offers high contrast and visibility without
the need to use stains. This allows for the specimen to be viewed in their
natural state. This technique is particularly beneficial when it comes to
viewing transparent/colorless specimen. Some of the specimens that can be
viewed using this approach include such live microorganisms as protozoa and
molds among many others.
The AmScope T490A-PCT has a solid metal construction
with a special enamel layer that is resistant to both corrosion and stains.
This ensures that the microscope remains stable during use and that it can last
for a long time.
The solid construction of the microscope also extends to the
double layer mechanical stage of the microscope. For the mechanical stage
system, a stage stop has also been included to protect the slides and the
objectives from damage. Here, the stop has to be set in order to prevent the
stage from moving above a given point and thus keep the objectives (40x and
100x) from coming into contact with the slides.
The microscope also comes with:
One bottle of Immersion oil
(3) Color filters; blue,
green, and yellow
A spare halogen
A spare fuse
A cover dust
An instruction manual
Amscope T490A-PCT Pros and Cons
It is one of the least
expensive phase contrast microscopes with great, stable design as
well as sufficient resolution to decipher structures as is the case with high end microscopes.
Because it allows for
different microscopy techniques, this microscope covers tremendous range
It comes with a trinocular
head that allows for camera attachment. The camera can be removed and replaced
depending on the needs of the user
If a camera is included in the
microscope, the device can be an excellent tool with increased functionalities
such as measuring and even manipulating the images for a better view. In
addition, this allows for sharing, which is particularly beneficial for
education purposes and presentations.
The 100x phase setting on
the turret condenser may need full phase alignment during set up.
It currently uses a halogen bulb,
where users may want to replace with LED bulbs.
The AmScope T490A-PCT is an excellent microscope
that offers a number of opportunities for users both for educational and
research purposes. With all the right components in place, the microscope can
be used for phase contrast, brightfield as well as darkfield, which means that
users can use the microscope to observe a wide range of specimen using just one
microscope. The microscope can be used by students as well as professionals.
Because it is a durable item, students can use it for a long time as long as it is taken care of appropriately. It also comes with high levels of magnification as well as an advanced optical design to ensure high quality images. With more great pros than cons, this is a device worth getting.
Have your say about what you just read on MicroscopeMaster! Leave me a comment in the box below.
Amazon and the Amazon logo are trademarks of Amazon.com, Inc. or its affiliates
The material on this page is not medical advice and is not to be used for diagnosis or treatment. Although care has been taken when preparing this page, its accuracy cannot be guaranteed. Scientific understanding changes over time.
** Be sure to take the utmost precaution and care when performing a microscope experiment. MicroscopeMaster is not liable for your results or any personal issues resulting from performing the experiment. The MicroscopeMaster website is for educational purposes only.
MicroscopeMaster.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means to earn fees by linking to Amazon.com and affiliated sites.