| Author | Message | ||
     Mike_rgb Tinkerer Username: Mike_rgb Post Number: 6 Registered: 08-2006 Rating: N/A |
Hi Glenn I tried turning the screw out until it locked & then tried power, focus adjustments. I was surprized to see as I worked the rings it was not really locked so I backed it out again & again. It was then I noticed the 80mm mark was way past the heavy white line. So I turned the screw back in until the 80mm mark was lined up with the line. When I turned the power ring back it lined up on 28mm mark. It seems this screw may be an adjustment for lining up the power settings. Not once did the focus ring ever become smooth to turn no matter where the screw was set. The focus ring feels very rough while turning either way. This is the same rough grating on both the normal & Macro settings. I only have one other AF lens a Nikor 75-240mm D. It is has a smooth focus adjustment also the objective lens moves in and out like my MF lenses do. None wiggle or have scratch marks on their tubes. I feel that the main problem is in the focus area of this lens, everything else seems to work fine. Finding a blowup or repair manual for this Sigma seem like a good place to start my first lens tear down, & reassembly. I remember reading ( Good lens seldom ever get sold ) when I first got started in Photography. Where does a SIGMA lens fit on the quality ladder? Mike |