Metoprolol can be an anti-hypertensive (blood pressure) drug classified like a selective beta-1 receptor blocker, also called a beta adrenergic blocker. Metoprolol is sold within the brands Lopressor and Toprol-XL and is also accessible in immediate-release and prolonged-release formulations. In addition to high blood pressure, metoprolol is prescribed to treat conditions including angina pectoris (chest pain) abnormal heart rhythms, migraine, tremors, congestive heart failure, bleeding through the esophagus, negative effects of antipsychotics, and to prevent second strokes. Therefore, when shooting in macro, it is easy to get a shallow depth of field if utilizing a large aperture. We often make use of the F8, F11, F13 such small, and medium-sized aperture to look at photograph to ensure the photo has clear range. If you use a 100mm macro lens to shoot the insects' close-up, even with the F13 aperture, the depth of field is extremely shallow, and sometimes need to utilize the manual focus function to carefully adjust the focus position to spotlight your eyes of insects to make the image more vivid.