Digital camera lens marked "f = 6.3-18.9mm 1: 3.1-5.6", what does it mean ah, how this camera
Say a few words. Floating iris is designed so that the main purpose is to reduce the lens diameter, weight and reduce manufacturing costs. The disadvantage is that you have to endure the focal length of the lens aperture aperture also narrow the pain, in low light can not hand-held camera, can not change the depth of field, had to open a large sensitivity, endure the photo noise.
Is to tell you that front is the focal length, behind that is the aperture. Also tell you that the lens aperture will change with the focal length changes, when you use the maximum focal length, the aperture will automatically be reduced to a minimum. This is the "floating aperture lens" he and fixed focus, constant large aperture zoom lens quality is very different, can not be compared.
This is the relatively large size of the DC drive it shows that the actual focal length is from 6.3MM (F3.5) -18.9MM (F5.6) but because of the size of the equivalent size of the focal length than this large (according to different photosensitive size Determine the conversion factor) do not know who is the head of the aperture you are wrong should be 1: 3.5-5.6 3x optical zoom
