Word Finder - eyepiece

definition

The lens (or combination of lenses) at the eye end of a microscope or telescope by which the image is viewed.

For the eyepiece the other rule holds; the object is represented by narrow pencils, and it is hence possible to subject the relatively great object, viz.

The calculation is most convenient if the micrometer is left in the position of zero and the object is moved till one of its edges corresponds to the zero mark of the eyepiece scale.

This consists of a scale on a little glass plate, which, instead of a cross wire, is placed in the eyepiece.

As fractions of intervals can only be estimated in this method, a measurement with such an eyepiece scale can of course not be as exact as with a screw micrometer ocular.

To center the condenser close down the iris diaphragm and remove the eyepiece.

You can rotate the eyepiece to better fit the object orientation.

I've obtained both my eyepiece reticles by this route.

These may be diminished by using different parts of the objective micrometer for the correction of the eyepiece scale, and the calculation of the size is based on the found mean value.

A second error can arise through the inaccuracy of the eyepiece micrometer, and also in the case of a screw micrometer through periodic faults of the screw, and through dead motion.

The eyepiece micrometer allows its errors to be diminished, if one measures at different points and then fixes a mean value.

With weak systems no auxiliary microscope is necessary, the eyepiece being removed and the scale viewed directly in the tube.

The eyepiece being removed the image of the metal plates b produced by the objective is seen.

In order to ensure for the eye a central position, there is fixed on the upper end of the tube in place of the eyepiece a disk of pasteboard or metal with an axial hole.

To determine the position of the anterior focal plane of the eyepiece, the eyepiece is placed on the stage with the eye-lens downwards.

This gives the distance of the anterior focal plane of the eyepiece from the bottom edge of the setting of the eyepiece and consequently also of the edge of the eyepiece carried by the upper end of the tube.

The same method can be used to determine the focal length of the eyepiece.

If a drawing prism is used above the eyepiece, and an objective micrometer is inserted, then if a scale is laid on the drawing board which is 25 cm.

Bronchoscopy A tube called a bronchoscope is put into the airway and, using an eyepiece, the doctor can see into the airways.

Temporarily remove the eyepiece and clamp the Camera lucida to the top of the eye tube, then replace the eyepiece.

As it was when bought, very dirty and scruffy, here shown with X10 eyepiece and manual stage.

The full field of the 20X eyepiece is used and the image quality is quite good at 20X viewing magnification.

All the above captures were taken with the camera fitted to the eyepiece tube without any eyepiece tube without any eyepiece.

The aluminum tube has an outside diameter of 1 1/4 inches to suit standard telescope eyepiece sizes.

Since there is no eyepiece, there can be no optical magnification as such.

To calibrate the eyepiece micrometer, the stage micrometer has to be focused using the objective to be used.

The measurement of specimen size with a microscope is normally made by using an eyepiece micrometer.

Images were taken using a CCD camera attached to the eyepiece tube of a stereo microscope using a x1 paired objective with no eyepiece.

This means it can be screwed onto a standard camera eyepiece nosepiece or included in a filter wheel.

Anything you see can become a superb photomicrograph by aligning your camera to capture the image coming out of the monocular microscope's eyepiece.

Gently tipping the opened eyepiece onto a lint free cloth will remove the reticle.

The other fittings are brass and include a sliding sunshade and a pivoted eyepiece cover.

Repsolds in more recent micrometers under construction give a second motion to the eyepiece at right angles to the axis of the micrometer screw; this enables the observer to determine the zero of position-angle for his movable webs with the same accuracy as he formerly could only do for the so-called position-angle webs.

One drawback to this form of instrument is that the two webs cannot be viewed simultaneously, and therefore the observer must rely on the steadiness of rate of the clockwork and uniformity in the conditions of refraction whilst the eye is moved from one eyepiece to the other.

In more recent instruments at the observatories of the Cape of Good Hope and Paris the motion is transmitted from a separately mounted cone and clock by a light rod passing through a perforation in the pivot of the transit instrument and thence through bevel-wheels in the cube of the axis to a second rod leading to the eyepiece.

Suppose now the solar spectrogram to be viewed in the focus of Or, and the converging rays to be reflected by the prisms Pr and P, i till an image is formed in the focus of the eyepiece at the point where the axis of the eyepiece intersects From Zeitschr.

If the stellar spectrograph is viewed in the focus of 0 2 and the converging rays are reflected by the prism P2 to P4, no image would be seen in the eyepiece, for the rays would pass out directly through the parallel glass plate which is formed by the cementing together of the prisms P 3 and P 4.

The effect of turning the pinion V is, of course, to displace the focus both of the solar and stellar spectrographs in the field of the eyepiece, but this d .a displacement is easily restored by From Zeitschr.

One prong of the fork carries a microscope objective, wart of a vibration microscope, of which the eyepiece is fixed at the back of the clock and the Lissajous figure FIG.

At the same time, on land, the new necessities imposed on field artillery by the growing use of covered positions led to the development of scissors-telescopes (see Rangefinders) and panorama-telescopic sights (see Sights), in which the optical system was arranged with the tube of the telescope vertical and the object-glass and eyepiece systems at right angles to the axis of the tube.

In the Ramsden eyepiece (see Microscope) the focal lengths of the two piano-convex lenses are equal, and their convexities are turned towards one another.

The terrestrial eyepiece (see Telescope), which likewise ensures an upright image, but which involves an inconvenient lengthening, has also been employed in the binocular microscope.

This aberration can, however, be successfully controlled by a suitable eyepiece (see below).

The Off-Axis Guider works best with an illuminated reticle eyepiece so that very small deviations can be identified quickly and can be corrected accurately.

Spotter telescopes of between 60mm and 100mm aperture may be used to photograph the Moon simply by holding the camera lens to the eyepiece.

He would often talk about how his eyelashes would freeze to the telescope eyepiece.

Instruments have been invented by Alvan Clark and Sir Howard Grubb for measuring with the spider-line micrometer angles which are larger than the field of view of the eyepiece.

Then if the prism P4 is cemented to P3, a sharp image of such lines of the solar spectrograph as are visible in the field of view will be seen in the eyepiece.

These screens are usually embodied in the eyepiece.

The first compound miscroscope (discovered probably by the Middelburg lens-grinders, Johann and Zacharias Janssen about 1590) was a combination of a strong biconvex with a still stronger biconcave lens; it had thus, as well as the first telescope, a negative eyepiece.

In 1646 Fontana described a microscope which had a positive eyepiece.