Using the bright-field compound microscope. 1. Open the iris diaphragm all the way while using the low power objective. What happens to the field of view and the quality of the image? Now close the iris diaphragm. What happens to the field of view and the image? 2. Why should you always begin with scanning or low power objective? 3. Why were you asked to use only the fine adjustment knob after switching to 40X? 4. Complete the following table to calculate total magnification for the compound microscope: 5. What is the highest total magnification that can be achieved using the bright-field compound microscope? _____