Nikon L-Ke manual Attaching the Lenses, Condensers, Mounting the Objectives

microscope set up is about 500—lOOOX of the numerical aperture of the objective to be used. Note that in photomicrography it is useless to raise the magnification beyond the resolving power of the emulsion (usually about 0.05mm). However, since the resolution of the emulsion is higher than that of the naked eye, photographs are usually taken at a lower magnification and thereafter they are enlarged.

•Real field of view (in mm) represents the extent of the object that comes under observation. In higher magnification it becomes extremely small. Consequently, it is advisable to take aim at the object point to be exa- mined first under lower magnification and then revolve the nosepiece to higher magnification.

•When focus is on the center of the field, its circumference will usually be blurred, because a curvature of the image plane is unavoidable in the microscope, except when using a plan type objectives. In order to get sharp corner image, it is necessary to adjust the fine focusing knob and switch the focus from the center onto the corners.

•Depth of focus represents the thickness or height of the object in fi sharply seen when observation is made through the microscope. In photomicrogra- phy the depth of focus becomes smaller than the figure shown in the previous table. Therefore, careful attention must be made in focusing when taking microscope pictures.

By closing the condenser diaphragm, the depth of field can be made greater than the value shown in the table.

4.Condensers

ATTACHING THE LENSES

Before attaching the objective and the eyepiece to the microscope, first clean their outer lens surfaces. Even a slightly stained finger mark may often interfere with the image contrast.

1.Mounting the Objectives

Take special care in handling the objectives.

Before attaching the objectives on the nosepiece revolver, lower the microscope stage sufficiently. Securing each objective with the fingers of one hand, screw it into each nosepiece hole with those of the

other hand (Fig. 4). It is recommended to mount the objectives on the nosepiece or- derly from low to high powers so that the magnification of each objective augments as the revolver is rotated clockwise or counter- clockwise.

Microscope Model L-Ke has on its upper surface of the nosepiece revolver five blank spots (Fig. 5) on each of which the objective magnification can be Inked so that, by looking these Indica- tions from above, the

Type	Numerical Aperture
Abbe	1.30	Two	lenses
Abbe	1.30	Two	lenses
Aplanatic	1.40 Three lenses
Achromatic	1.25	Five	lenses
Achromatic	0.7	Four	lenses
(long focal-length type)
Universal Dark-Field Condenser	1.20-1.40 for
	dark-field
Low-Power Condenser	Single lens

Remarks

For central illumination (without oblique illumination slider)

For central and oblique illumination (with oblique illumi- nation slider)

For high-class microscopy

For high-class microscopy

Long focal-length type. Working distance 12mm. With turret-mounted annular diaphragms for phase-contrast and phase-interference microscopy.

Supplied in centerable mount. With outer diameter 36.8

mm.Objectives to be used lOX up to lOOX. Ideally suited for fluorescence work. lOOX objective used should have built-in adjustable iris diaphragm. Thickness of slide glass to be used, must be less than 1.2mm.

For low-power macro-objectives, e . g . , 1.2X, 2X, & 3X Plan Achromatic

objective located below can be identified with- out having to turn away your eyes from the eyepiece.

When rotating the re- volver, hold its outer milled rim with your thumb and first finger, but do not push the objective barrels, other- wise alignment of the

These condensers are not only capable of concentrating light-beam for better illumination of the image field, but also gives a great influence on the resolu- tion of microscope image, image contrast and depth of focus. In precise observation and photomicrography, the use of an achromatic or aplanatic condenser with the maximum numerical aperture 1.25 provided with an oblique illumination device and a filter case is specially recommended.

— 9 —

objectives may be trou- bled.

- 1 0 -