[jk8788]

點解兩款都係用135mm拍,但之後定焦135mm拍出o黎o既size大過變焦135mm o既size??請各位高人解答....

[jason_yeung]

size?
咩size?

[davylam]

file size?
Are u using the same ISO setting????

[jk8788]

sorry我係講緊個物件大小,例如我用變焦135mm影一個人全身full frame但用定焦135mm(同一距離)只可影到頭至大腿( cut 左腳)明明都係135mm(同一距離)但點解分別o甘大,係o米我支zoom有事o尼?

[genewch]

A zoom lens often has a less precise focal length. So the 135mm in the zoom lens may have a shorter real focal length, ie towards the wide angle side, <135mm. So you can take the whole person with the zoom while his/her legs are out of the picture with a prime 135mm. A prime lens should have a precise focal length, ie not much different from 135mm.