1 Leaf shutters are usually fitted within a lens assembly (central shutter), or more rarely immediately behind (behind-the-lens shutter) or, even more rarely, in front of a lens, and shut off the beam of light where it is narrow. 2  Focal-plane shutters are mounted near the focal plane and move to uncover the film or sensor.
DHEA levels begin to naturally decline by the age of 30. While normal levels for women in their 20s fall between 65 and 380 Âµg/dL, for women in their 30s and 40s, the average normal range is 45 to 270 and 32 to 240 Âµg/dL, respectively.
Normal levels of creatinine and BUN. Te normal range for creatinine in the blood may be 0.6 to 1.3 milligrams per deciliter (53 to 115 micromoles per liter), although this can vary from lab to lab, between men and women, and by age. Since men usually have high larger muscle mass, the amount of creatinine in the blood is often higher than women. In general,the normal BUN level ranges from 7 to 20mg/dL(2.5 to 7.1mmol/L).However, the normal BUN levels may vary with the lab, and your age.