The fine adjustment knob is used with the power objective on the microscope. Since the objective is already at the highest objective possible for that microscope, using the coarse adjustment knob would focus to much on the object making the details harder to read. Using the fine adjustment knob, you are able to see the fine details within the object or organism you are studying. The higher the power, the finer the knob and the lower the objective, the coarser the knob and objective.
The coarse focus knob should be used with the low power objective but not with the high power objective. The point of using the coarse focus knob is to bring the specimen into general focus before fine-tuning with the high power objective, which requires more precise adjustments.
The high power objective on a compound microscope typically has a magnifying power of 40x or 50x.
It allows you to see a close up of only a small area of the specimen being viewed
The adjustment knob that moves the body tube for focusing with the high-power objective lens is called the fine focus adjustment knob. It allows for precise adjustments to bring the specimen into sharp focus at high magnifications.
The objective lens that focuses closest to the slide is 100x, it has the longest lens so the highest power. Be careful not to crack the slide and make sure you use oil if it is an oil immersion lens.
The coarse focus knob should be used with the low power objective but not with the high power objective. The point of using the coarse focus knob is to bring the specimen into general focus before fine-tuning with the high power objective, which requires more precise adjustments.
First focus the microscope on the lowest objective using first the coarse djustment knob and then the fine adjustment knob. Once you have it in focus, move on and do the same for the next highest objective. Continue this process until you reach the highest objective and focus it in the same fashion.
All the threads can be in focus again using the high-power objective if a certain thread is focused using the control knob to make adjustments. The knob allows for very small changes to be made which will create a precise focus.
THE disadvantage of using high power objective is to
The course-adjustment knob moves the stage up and down quickly, and using it with a high-power objective can potentially damage the objective or slide due to a rapid change in focus. It is best to use the fine-adjustment knob when using a high-power lens for precise focusing.
Using the coarse-adjustment knob with the high-power objective can result in the objective lens getting too close to the slide, potentially damaging the lens or slide. This can also lead to the objective lens hitting the slide, causing a loss of focus and potential damage to both the lens and the slide.
You typically start with the low-power objective lens and the coarse focus knob when focusing your microscope. This allows you to bring the specimen into view quickly and then fine-tune the focus using the high-power objective lens and the fine focus knob.
You do not use the coarse focus knob on high power because it can damage the slide and the objective lens of the microscope. Use only the fine focus knob to bring the specimen into sharp focus on high power.
You shouldn't. You can cause the high objective to smash into the surface of the slide and crack it. Always use the fine adj. for high power and if you cannot get the high power in focus, reverse out to low again and do it over. Ideally, if you are in focus on low, you should be in focus at medium (may have to adjust a small amount) and if you are in focus under medium, when you swing the high power obj. into place, it should be in focus as well (may need a fine tune). Always reverse out and start all over again if you cannot focus it under high power. Deja Was Here
Using high power objective lense
The high-power objective magnifies the image 4x.
The fine adjustment knob is used to bring the image of an object on the slide into focus when under the high power objective lens. This knob allows for precise focusing by making small adjustments to the distance between the objective lens and the specimen on the slide.