سلام:
نکاتی پیرامون این تاپیک دارد
85mm f1.2 or 135mm f2. Which has less DoF
...As you would expect, at the same magnification, the faster the lens, the smaller the depth of field. This also means that the background close to subject will be blurred more by the faster lens. In this case the 50mm lens at f1.4 gives slightly greater blurring for objects up to about 1m behind the subject in focus. However as you go further back, the lens with the largest physical aperture starts to show the most blur, and by the time you're at infinity, the 135mm lens at f2 lens will give almost twice as much blurring (actually 1.9x as much)...
کد:
http://photo.net/canon-eos-digital-camera-forum/00VbKl