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From the above formulae, d= λ /(4*NA).Here, λ :is 550nm(the wavelength at the center area of the visible light).
NA is the NA of the lens closest to the CCD of the microscope
optical system divided by the magnification, and this resolving
power controls the overall resolving power. In the optical system
of the microscope, this NA is greatest in a low-magnification
lens. At present, the maximum value of NA is perhaps about 0.04.
If this value is used to calculate resolving power, d = 0.55/(4*0.04)
= 3.43 λ. Therefore, resolving power required by the CCD
= 3.4 λ.
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d = 0.55/(4*0.04) = 3.43 λ. Therefore, resolving power required by the CCD = 3.4 λ m.
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If the pixel pitch of the CCD used in the camera is on the order of 3.4 λm or less, the image of the subject is sufficiently resolved. A CCD with
square pixels of 3.4λm is used in the Nikon Digital Sight DS-Fi1/5Mc camera heads.
2) Image refresh rate
Depending on the image from the digital still camera, the image
needs to be refreshed in a short time when the focusing or angle
of view is adjusted. Generally, moving pictures require 30 Hz
and quasi moving pictures require 15 Hz. In the case of digital
still cameras, the speed at which data is read from the CCD is
limited. If the number of pixels is large, image reading time
is generally slower. As a way of overcoming this limitation, the
CCD has a mode that thins the data so that it can be read more
quickly. The general way of using a CCD is thus to make focusing
and angle of view adjustments based on this thinned image, and
to use high picture quality when shooting the picture.
The Nikon Digital Sight DS-Fi1 camera head inputs an image equivalent to SXGA quality at 7.5 Hz from the CCD, and can
store the full 5M picture while displaying it on the LCD at the front or on an optionally available display. (Sensitivity correction and other adjustments
when the mode is changed are all automatic.) In our estimation, we are able to achieve a balance here between the definition of the displayed image and
a moving-picture-like frame rate.
3) Equipped with standard PC interface
There is a growing need to export images to a PC in order to store
them, analyze them, or even send them to people around the world.
In the past, a dedicated interface board was required when exporting
images to a PC, but nowadays, PCs come standard equipped with
interfaces such as LAN Ethernet or USB.
The Nikon is equipped with both LAN Ethernet and USB ports for
easy connection to PCs.
4) Ease of use: It is equipped with operating
methods compatible with the various observation procedures on
a microscope
As with general digital cameras, if the photographer does not
adjust shooting conditions to suit the various observation procedures
of the microscope, it will not be possible to achieve desired
results. Nikon believes that an easy-to-use camera must be able
to accommodate the microscopes various observation procedures.
For photographers who want a camera that makes shooting pictures easy
The Nikon Digital Sight DS-L2 control unit provides a variety of scene buttons that are easy to understand at a glance.
These buttons optimize gamma tables and metering modes. In the field of biomedical microscopes, these scenes are brightfield observations and DIC observations,
and with industrial microscopes, they would be semiconductor wafers, printed circuit boards, and so on. Nikon’s COOLPIX line of digital still cameras
for consumers has similar easy-to-understand shooting modes, such as for night scenes or portraits.
For photographers who want a camera that takes exactly the kind of picture they want
The Nikon Digital Sight DS-L2 control unit has an Advanced mode that lets the photographer adjust various shooting parameters. Photographers can also
store sets of customized parameters as their own original scene modes.
