A more advanced 100 square foot colored concrete patio installation costs homeowners between $713 and $933 on average, which includes $188 to $204 worth of materials and $525 to $728 worth of labor costs.
The Diaphragm or diaphragm control lever regulates the amount of light passing through the slide specimen on the microscope stage.
The iris and the pupil control how much light to let into the back of the eye. When it is very dark, our pupils are very large, letting in more light. The lens of a camera is able to focus on objects far away and up close with the help of mirrors and other mechanical devices.