How to count and count cells under the microscope field of view?
"The number of cells is inversely proportional to the square of the magnification" seen under the microscope field of view.
In other words, the higher the magnification of the microscope, the smaller the field of view, the larger the cells, and the smaller the number of cells (inversely proportional).
For example: Suppose we increase the objective lens from 4X to 40X, and the magnification is 10 times the original, so the field of view becomes 1/100 of the original (inverse square ratio), so the number of cells also becomes 1/100 of the original (assuming that the cells are uniform distribution case).
Example 1: 64 uniformly dispersed cells were observed with a 100X microscope, how many cells can be seen with a 400X microscope?
Answer: 100x->400x, zoom in 4 times. 4 times the length and 16 times the area. The number is 64*1/16=4
Example 2: If 500 uniformly distributed cells can be observed with a 4X objective lens, how many cells can be seen if the objective lens is replaced with a 40X microscope?
Answer: 4x->40x, zoom in 10 times. 10 times the length and 100 times the area. The number is 500*1/100=5
Example 3: 64 bacteria can be seen under a 50X microscope, how many can be seen at 100X?
Answer: 50x->100x, magnified by 2 times. Twice the length and four times the area. The number is 64*1/4=16
