4. Turn on the illuminator and open the diaphragm fully. If there is a condenser, position it as  high as it will go, so that the top lens of the condenser unit is level with the stage aperture.  Center the specimen over the stage aperture. 5. Position the scanning objective (4x) as close to the slide as possible; then, while looking  through the oculars, use the coarse adjustment knob to back off slowly until the specimen  comes into focus. 6. Use the diaphragm (and/or the transformer voltage regulator) to adjust the light intensity as  necessary, and again center the specimen by moving the slide. 7. Switch from the scanning lens (4x) to the low-power objective (10x). Make certain the  objective clicks into position. If the specimen stays in focus, your microscope is  parfocal .  Parfocal means that the microscope has been designed in such a way that once the specimen  is clearly focused and centered it remains in focus while changing objectives, You can sharpen  the focus by small adjustments of the fine adjustment knob.  If your microscope is not in focus after changing objectives, you may have to use the  coarse adjustment knob and then the fine adjustment knob. But remember, do not do this with  the high-power or oil-immersion objectives in position. Ask your instructor for help if you have  difficulty focusing your microscope. Recenter the specimen, adjust the diaphragm, and adjust the position of the condenser  to increase the contrast of the specimen. 8. Switch to the high-power objective (43x) and adjust the focus using the fine adjustment  knob. These procedures are usually used when examining a wet mount or a commercially  prepared microscope slide. Always use clean microscope slides. Always proceed from the  lowest power to the highest power objectives, making minor focus and light corrections as  necessary. Learn to fine-tune your microscope. The image that you see in the microscope is affected by several factors: the orientation  of the image, the total magnification, the size and brightness of the field of vision, the plane of  focus, the depth of focus and the contrast of the specimen. Hold your slide of the letter "e" so that the letter is in a normal reading position. Then  place it on the stage in that position and examine it with the low-power objective. Move the  image to the right, left, upward, and downward, and notice the direction in which you have to  move the slide. Draw how the "e" appears under the microscope._______________________ When you want to point out something of interest in the field of vision to someone, you  can describe its approximate location by referring to the field of vision as a clock. Thus, you  could tell them to "look at 3 o’clock", or "look just off-center toward 3 o’clock", and so forth.  Alternatively, in some microscopes, a thin black line appears to cut across the field. This is a  pointer that has been added to the ocular of your microscope so that you can point out  a. Orientation of the Image The Microscopic Image: