GENERAL HISTOLOGY

Detailed explanation-1: -When on a high powered lens one should never use the coarse adjustment. The coarse adjustment makes a very large vertical movement.

Detailed explanation-2: -CAUTION: NEVER, EVER, use the coarse adjustment knob with the high power objective. This could break the lens. Multiply the power of the ocular lens, by the power of the objective lens.

Detailed explanation-3: -Coarse and fine adjustment The coarse adjustment knob should only be used with the lowest power objective lens. Once it is in focus, you will only need to use the fine focus. Using the coarse focus with higher lenses may result in crashing the lens into the slide.

Detailed explanation-4: -At a high power objective, the focus will change rapidly as the objective lens is adjusted, so only the fine focus knob should be used in order to prevent overshooting the correct focal plane.

Detailed explanation-5: -If you focus the high power objectives with the coarse focus knob, then you risk slamming the objective into the slide, risking the damage of both. Some high power objectives are spring-loaded, with a front-part that retracts when touched by the slide. This is a protective mechanism.