What is microphotography?

Microphotography is a technique to record the fine structure of an object observed in the field of view of a microscope with a microphotograph for further analysis and research. In scientific research, especially in the fields of medicine and biology, it has become a routine and indispensable research technology.

Experimental principle

Microphotography is a method of projecting the image in the eyepiece onto the photographic negative, exposing the negative and recording the phenomena in the field of vision. In photomicrography, the light emitted by the tiny object W in the film enters the objective O, and an enlarged and inverted real image is generated at I 1, which is slightly lower than the focal plane Fe of the eyepiece, and the distance between them is d..

After the real image is further amplified by the eyepiece, it leaves the eyepiece and forms an enlarged real image at I2 on the screen. If the screen is ground glass, you can focus on the view, and then change the negative after focusing, and you can shoot.

Experimental supplies

1. Equipment:

Compound microscope and its photographic device, black and white film, developing tank, thermometer, electric stove, darkroom bag, cassette, photographic paper, scissors, plastic plate, beaker, measuring cylinder, balance, biological sample, etc.

2. Reagent:

① Developer (D72 universal developer):

Dissolve the small bag powder with 50℃ 150ml distilled water, then put the big bag powder into it, stir until it is completely dissolved, and add water to 250ml. Use when the temperature drops to about 20℃.

(2) stationary liquid:

Dissolve the powder completely with 150ml distilled water at 50℃, then add water to 250ml, and use it when the temperature drops to about 20℃.

Experimental principles and methods

Microphotography is a technology that takes optical images of samples in the field of view of a microscope through a photographic device.

The specific experimental steps are shown in the following figure:

Installation and debugging of microphotograph device

Adjustment of microscope optical path: Through adjustment, the illumination beam is integrated with the optical axis of the microscope optical system.

Loading film

View focusing

Exposure:115 sec (metering first: green light can be exposed correctly)

Black and white film development: develop for 3min→ stop developing 10s→ fix 15min→ rinse with running water for 30min → dry.

Print enlargement: framing and focusing → exposure → development → stop display 10 second → fixing 15 minutes → water washing: running water washing for 30 minutes.