[catolo]

點先知道支鏡有冇走蕉,須要返CS cal鏡呢?有冇方法check架?thx

[hanny]

if you are using 50d or 5d mark 2

than no need to cal
becasue body build in fine tune focusing system
you can tune yourseft

if you feel than is out focusing
than you can try using a ruler and big your lens to maxium aperture
under a bright enviroment and a right focusing distance
using a tripod to test shoot the number on the ruler

noramlly only some lens that can do f2.8 or more large aperture like f1.8 /1.4/1.2 that have to test

the other lens no meaing to test