09-14-2010, 05:08 PM
Technical question; My Sigma 50mm 2,8 macro has a diaphragm control ring which I must lock in P and S mode and need do nothing else. Wen using the A and M mode, you have to "unlock the button and set the diaphragm value by turning the ring". <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/huh.gif' class='bbc_emoticon' alt='' /> I have never seen this! What does it actually mean? Do I have to adjust this for every different shot? I apologize in advance if my question is stupid, but would appreciate your help <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='' /> Kindly Ignorant Wolf