Note: If the image is too dark you Using the Oil-immersion lens might want to open the iris diaphragm a In order to get a good look at most little. bacterial cells, you will need to use the lens. First center the oil- immersion (only about four times more powerful specimen and focus with the high-dry than Leeuwenhoek's microscope which objective (43x) then follow the was constructed over 300 years ago!) procedure below. The ocular lens magnification of your Rotate the nosepiece so that microscope is 10x. the specimen is between the high-dry and lenses. oil-immersion Examine the smallest objective and locate the magnifying power. Place a SINGLE drop of (you should see a number on the side immersion oil on the slide directly over of the objective) the specimen. Enter this number in Table 2 below. Watching from the side, rotate the nosepiece to bring the oil- Now find and record the immersion lens into position. magnifications of each of the other objectives. Focus with the fine focus Table 2: Magnifying Power of adjustment knob ONLY. Objectives. magnification when the high-dry Magnification refers to the objective is used. apparent increase in size of an object when viewed through a microscope. Leeuwenhoek's simple microscopes had a magnifying power of about 270 times the diameter of the specimen. The modern compound microscope combines the magnifying power of the ocular lens and the objective lens and provides a magnifying power of about 1,000 x The Total Magnification is found by multiplying the magnifying power of the ocular lens by the magnifying power of the objective lens that you are using. Q: Calculate the total
Using the Oil-immersion lens In order to get a good look at most bacterial cells, you will need to use the oil- immersion lens. First center the specimen and focus with the high-dry objective (43x) then follow the procedure below. Rotate the nosepiece so that the specimen is between the high-dry and oil-immersion lenses. Place a SINGLE drop of immersion oil on the slide directly over the specimen. Watching from the side, rotate the nosepiece to bring the oil- immersion lens into position. Focus with the fine focus adjustment knob ONLY. Note: If the image is too dark you might want to open the iris diaphragm a little. (only about four times more powerful than Leeuwenhoek's microscope which was constructed over 300 years ago!) The ocular lens magnification of your microscope is 10x. Examine the smallest objective and locate the magnifying power. (you should see a number on the side of the objective) Enter this number in Table 2 below. Now find and record the magnifications of each of the other objectives. Table 2: Magnifying Power of Objectives. Magnification refers to the apparent increase in size of an object when viewed through a microscope. Leeuwenhoek's simple microscopes had a magnifying power of about 270 times the diameter of the specimen. The modern compound microscope combines the magnifying power of the ocular lens and the objective lens and provides a magnifying power of about 1,000 x The Total Magnification is found by multiplying the magnifying power of the ocular lens by the magnifying power of the objective lens that you are using. Q: Calculate the total magnification when the high-dry objective is used.