Though now considered primitive, the use of a single, convex lens for viewing is still found in simple magnification devices, such as the magnifying glass, and the loupe.
Only, the only(+сущ.)
A simple microscope is a microscope that uses only one lens for magnification, and is the original design of light microscope.
Present, to present, to be present
Optical microscopes are the oldest design of microscope and were possibly designed in their present compound form in the 17th century.
To prove, to provide
It took about 150 years of optical development before the compound microscope was able to provide the same quality image as van Leeuwenhoek's simple microscopes, due to difficulties in configuring multiple lenses. Still, despite widespread claims, van Leeuwenhoek is not the inventor of the microscope.
The whole of the optical assembly is traditionally attached to a rigid arm which in turn is attached to a robust U shaped foot to provide the necessary rigidity.
Some, the same
Some microscopes make use of oil-immersion objectives or water-immersion objectives for greater resolution at high magnification.
The vast majority of modern research microscopes are compound microscopes while some cheaper commercial digital microscopes are simple single lens microscopes.
It took about 150 years of optical development before the compound microscope was able to provide the same quality image as van Leeuwenhoek's simple microscopes, due to difficulties in configuring multiple lenses. Still, despite widespread claims, van Leeuwenhoek is not the inventor of the microscope.
All modern optical microscopes designed for viewing samples by transmitted light share the same basic components of the light path, listed here in the order the light travels through them: In addition the vast majority of microscopes have the same 'structural' components.
The same controls enable the microscope to adjust to specimens of different thickness.
Feature, future, further
Other features may be lamp controls and/or controls for adjusting the condenser.
The condenser may also include other features, such as a diaphragm and/or filters, to manage the quality and intensity of the illumination.
Unable, to enable, value, volume
The same controls enable the microscope to adjust to specimens of different thickness. In older designs of microscopes, the focus adjustment wheels move the microscope tube up or down relative to the stand and had a fixed stage.
They were awkward in use, but enabled van Leeuwenhoek to see detailed images.
Typical magnification values for eyepieces include 2×, 5× and 10×.
A typical value of the enlargement factor is around 5× (for the case of 35mm film and a 15x10 cm (6×4 inch) print).
Variable, various, varied
The frame provides a mounting point for various microscope controls.
Very, the very(+сущ.), to vary
Basic optical microscopes can be very simple, although there are many complex designs which aim to improve resolution and sample contrast.
Van Leeuwenhoek's home-made microscopes were very small simple instruments, with a single, yet strong lens.
6. Устойчивые словосочетания
According to, in accordance with
These entries are numbered according to the image on the right.
As high as/as many as/ as much as/ as littli as/ as low as
Numerical apertures as high as 1.6 can be achieved.
Due to
Due to the difficulty in preparing specimens and mounting them on slides, for children it's best to begin with prepared slides that are centered and focus easily regardless of the focus level used.
Compound microscopes are heavier, larger and more expensive than simple microscopes due to the increased number of lenses used in construction.
It took about 150 years of optical development before the compound microscope was able to provide the same quality image as van Leeuwenhoek's simple microscopes, due to difficulties in configuring multiple lenses. Still, despite widespread claims, van Leeuwenhoek is not the inventor of the microscope.
For example/for instance
Before development of Köhler illumination the image of the light source, for example a lightbulb filament, was always visible in the image of the sample.
The former
The former typically ranges from 5× to 100× while the latter ranges from 0.14 to 0.7, corresponding to focal lengths of about 40 to 2 mm, respectively.
The latter
The former typically ranges from 5× to 100× while the latter ranges from 0.14 to 0.7, corresponding to focal lengths of about 40 to 2 mm, respectively.
In addition
In addition the vast majority of microscopes have the same 'structural' components
In order to
Focusing starts at lower magnification in order to center the specimen by the user on the stage.
In turn
The whole of the optical assembly is traditionally attached to a rigid arm which in turn is attached to a robust U shaped foot to provide the necessary rigidity.
Rather than
By using interference rather than absorption of light, extremely transparent samples, such as live mammalian cells, can be imaged without having to use staining techniques.