microscope focus rack block focusing mount

Focusing holders hold the microscope body and contain the mechanism that raises or lowers the body to focus on the specimen. Complete stands include their own focusing holders. But for other kinds of tasks, however, it may be necessary to mount the microscope body on a boom arm stand or directly onto a machine or some other surface. The focusing holders below offer a range of options for such applications.

coarse and fine focus rack block

Coarse and Fine Focus Block/Holder focus holder with coaxial coarse and fine focus for high magnification applications where precise fine focus adjustment is required. Rack and pinion mount allows smooth, precise focusing over 33mm of travel. Coarse and fine focus mechanism incorporates a slip clutch and tension adjustment.
Focusing holders hold the microscope body and contain the mechanism that raises or lowers the body to focus on the specimen. Complete stands include their own focusing holders. But for other kinds of tasks, however, it may be necessary to mount the microscope body on a boom arm stand or directly onto a machine or some other surface. The focusing holders below offer a range of options for such applications.

coarse focus and fine focus adjustment focusing knob

Coarse vs Fine Adjustment

difference between coarse and fine adjustment is the range that they have. The coarse adjustment covers the entire range from minimum to maximum. In contrast, the fine adjustment only covers a fraction of the entire range. The bare minimum range for the fine adjustment is the discrete step increment of the coarse adjustment, in order to cover the entire range. It can also be larger, depending on the designer of the device.
character:
1.Coarse adjustment has steps in large increments while fine adjustment has steps in much smaller increments
2.Coarse adjustment covers the entire range while fine adjustment only covers a fraction of the entire range

By chutongelec

Eyepiece reticle stage graticule

eyepiece reticle/graticule patterns of Chutong in sizes to fit all microscopes and magnifiers,if you need any special size for your eyepiece,please send us the picture or drawing of eyepiece, then we design the reticle graticule suitable for you.

Eyepiece graticules

include scales for measuring linear dimensions, circles for estimating diameters and radii, and a protractor for angles. Scales can be calibrated by comparison with a stage graticule, supplied in convenient microscope slide format.

there is also another type reticle for objective,Stage graticules (also known as stage micrometers), supplied in a convenient microscope slide format, are used to calibrate microscope eyepiece graticules. Eyepiece graticules give a reasonably accurate gauge of viewed object sizes, but, owing to differences in the optical systems of different objectives and eyepieces, calibration is needed for accurate work. This is simply done by placing the stage graticule on the microscope stage and viewing it through the microscope. Comparision of the eyepiece graticule with the stage graticule enables either a correction factor to be calculated or, perhaps, in bespoke systems, the optical spacing to be adjusted to eliminate the magnification error.

 

Stage graticule reticle
cross reticle x y axis of eyepiece

Difference between digital microscope and stereo microscope
difference between a stereo microscope and a digital microscope is the magnification. With a stereo microscope the magnification is found by multiplying the lens magnification by the eyepiece magnification. Since the digital microscope does not have an eyepiece, the magnification cannot be found using this method. Instead the magnification for a digital microscope is found by how many times larger the sample is reproduced on the monitor. Therefore, the magnification will depend on the size of the monitor. The average digital microscope system, which has a 15″ monitor, would result in an average difference in magnification between an optical microscope and a digital microscope of about 40%. Thus the magnification number of a stereo microscope is usually 40% less than the magnification number of a digital microscope.[citation needed]

Since the digital microscope has the image projected directly on to the CCD camera, it is possible to have higher quality recorded images than with a stereo microscope. With the stereo microscope, the lenses are made for the optics of the eye. Attaching a CCD camera to a stereo microscope will result in an image that has compromises made for the eyepiece. Although the monitor image and recorded image may be of higher quality with the digital microscope, the application of the microscope may dictate which microscope is preferred.[citation needed]