Operating the Optiphot 2-Pol Optical Microscope
Basic Instructions on Microscope Use
- If you would like to use reflective light turn the knob on the Nikon Transformer.
As you turn the knob the green bar will light up indicating the amount of
light you are transmitting onto the sample.
-OR-
If you would like to use transmission light flip the power switch on the base of the microscope. Using the slide control to the right of the power switch you can control the amount to light you are transmitting through the sample.
- Rotate the objective lens piece to a small magnification (5x or 10x) to
begin with. This can be done by gently twisting the silver ridged rim of the
objective lens set. Make sure the lens of desired magnification is pointing
down at the sample. Make sure that the lens piece settles securely.
- With a prepared slide, place the slide onto the stage, secure with the specimen
grip. Bring the specimen into the path of light. You can move the specimen
around the stage by the two silver knobs on top of the stage. One controls
the horizontal and vertical directions while the other controls the left right
directions.
- Loosen the coarse focus ring to its limit. This is the inner most ring
on the large knob located on the right and left of the microscope.
- Adjust the eyepiece to your comfort, try adjusting the diopter. This can
be done by twisting the top of the actual eyepiece. Look into the eyepiece.
- Using the coarse focus knob focus onto the specimen. The coarse focus knob
is the second ring on the large focus knob located on the right and left of
the microscope. When you have reached a focused position tighten the coarse
focus ring. Fine tune the focus on the sample with the fine focus knob. The
fine focus is the outer most ring on the knob.
- You can increase magnification by rotating the objective lens set to the
desired magnification. Again you will need to adjust the focus appropriately
taking care not to damage either the objective lens or the sample by colliding
them.
- When using the microscope the more light that hits the sample the better resolution you will get but using less light will improve the contrast. This can be controlled by opening and closing the condenser lens aperture.
Additional Information on the Microscope
- Field diaphragm control ring
Located as the bottom most ring in the center of the microscope. Determines the illuminated area on the specimen. Generally keep the diaphragm so that the circumference of the area is just about as large as the field of view through the eyepiece.
- ND filter cassette
Located just above the field diaphragm ring. Reduces the amount of transmitted light onto the specimen. ND2 transmits 1/2, ND4 transmits 1/4, ND16 transmits 1/16. The fractions multiply when used together. ( ie. ND2 and ND16 transmits 1/32). This feature is useful when you want to control brightness but are using the photo intensity (the photo button on the left base of the microscope set light level to nine). This is beneficial when you are taking pictures and need to compare them and use the same conditions.
- Filter holder of microscope
Located in the rear of the micrscope near the lamp housing. Filters that might be used in the filter holder- NCB11 is used for color balancing in general microscopy and photomicroscopy. It is the one that is currently in the filter holder. GIF is used for retardation measurement and contrast adjustment. Use the GIF filter for phase contrast microscopy and monochrome photomicroscopy.
- 1/4 l Slide and Tint Plate
Located as a sliding cassette just below the top polarizer. If the slide is in the middle position no filter is being applied. Pushed in, the tint plate (530nm) is placed in the field of view. Pulled out the 1/4 l plate is placed in the field of view. The 1/4 l plate can be used for very weak birefringence.
Techniques
- Dark Field Microscopy
Dark field microscopy can be used when reflected light is being used to examine the specimen. Use the dark field objective lens set (see below on how to change the objective lenses). Adjust the knob on the left of the microscopy that has a label PUSH B.F., PULL D.F. Pull the knob until fully extended. You need to get the maximum amount of light into the microscope as possible. To do this: Orient the top polarizer to 0û , the 1/4l slide should be in the center position and both apertures on the rear neck region of the microscope need to be completely opened.
- Changing the set of objective lens
Using the hexagonal wrench located on the back of the microscope (pull out on the either of the small slits on the base of the neck of the microscope) The small hole located in the microscope housing on either the left or right side of the microscope is where you need to insert the wrench. Loosen the lens set and very gently slide out. To replace slide the set back in and tighten it down very gently. Take care not to over tighten the set. Make sure that the objective lenses rotate freely and easily.
- Centering the Condenser Lens
First, focus an image with the objective lens you wish to center. Next close the field diaphragm until a polygon shape appears. Using the condenser lens adjustment knob (smaller knob on left of microscope similar the fine/coarse focus knob), adjust until a very sharp picture appears. Finally center the image on the center cross lines. Repeat until the target remains centered while being rotated. Repeat for each objective lens.
- Birefringence
For transmission light the one of the cross polarizers is located between the objective lenses and the eyepiece on the ring with the degree markers. The knob on the right side controls whether or not the polarizers are being used. If the knob is pushed in then what you see in the microscope is through a polarizer. The second polarizer is located below the stage, the last ring on the condenser lens. There are markers indicating 0, 90, 180 and 270°. If both the top and bottom polarizers are set to 0° then the polarizers are actually crossed and at 90°. If the top is at 90°and the bottom is at 0° then the polarizers are not crossed and would be at the relative 0 or 180°positions. For reflected light the cross polarizers are located as a sliding case on the neck of the microscope. The polarizer is in the field of view when the right most position is being used. The rotating wheel turns the polarizer.
Additional Information on the Microscope
- Field diaphragm control ring
Located as the bottom most ring in the center of the microscope. Determines the illuminated area on the specimen. Generally keep the diaphragm so that the circumference of the area is just about as large as the field of view through the eyepiece.
- ND filter cassette
Located just above the field diaphragm ring. Reduces the amount of transmitted light onto the specimen. ND2 transmits 1/2, ND4 transmits 1/4, ND16 transmits 1/16. The fractions multiply when used together. ( ie. ND2 and ND16 transmits 1/32). This feature is useful when you want to control brightness but are using the photo intensity (the photo button on the left base of the microscope set light level to nine). This is beneficial when you are taking pictures and need to compare them and use the same conditions.
- Filter holder of microscope
Located in the rear of the micrscope near the lamp housing. Filters that might be used in the filter holder- NCB11 is used for color balancing in general microscopy and photomicroscopy. It is the one that is currently in the filter holder. GIF is used for retardation measurement and contrast adjustment. Use the GIF filter for phase contrast microscopy and monochrome photomicroscopy.
- 1/4 lamba Slide and Tint PlateLocated as a sliding cassette just below the top polarizer.
If the slide is in the middle position no filter is being applied. Pushed
in, the tint plate (530nm) is placed in the field of view. Pulled out the 1/4
lamba plate is placed in the field of view. The 1/4 lamba plate can be used
for very weak birefringence.
Techniques
- Dark Field Microscopy
Dark field microscopy can be used when reflected light is being used to examine the specimen. Use the dark field objective lens set (see below on how to change the objective lenses). Adjust the knob on the left of the microscopy that has a label PUSH B.F., PULL D.F. Pull the knob until fully extended. You need to get the maximum amount of light into the microscope as possible. To do this: Orient the top polarizer to 0û , the 1/4l slide should be in the center position and both apertures on the rear neck region of the microscope need to be completely opened.
- Changing the set of objective lens.
Using the hexagonal wrench located on the back of the microscope (pull out on the either of the small slits on the base of the neck of the microscope) The small hole located in the microscope housing on either the left or right side of the microscope is where you need to insert the wrench. Loosen the lens set and very gently slide out. To replace slide the set back in and tighten it down very gently. Take care not to over tighten the set. Make sure that the objective lenses rotate freely and easily.
- Centering the Condenser Lens First, focus an image with the objective lens you wish to center. Next close the field diaphragm until a polygon shape appears. Using the condenser lens adjustment knob (smaller knob on left of microscope similar the fine/coarse focus knob), adjust until a very sharp picture appears. Finally center the image on the center cross lines. Repeat until the t
