Archived posting to the Leica Users Group, 2012/11/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]No, there is always an offset ( and gain error) in any system, even an auto-calibration one. Same is true of Granite Flats, super accurate micrometers, laser rangefinders, etc. Remember those tiny calibration tags on equipment? I worked in a NASA lab, and yearly or more often every piece of equipment was in for calibration. In this case, what is zero error? How does the camera tell it is at zero error? Yes, it can be calibrated out... back to some form of repeated re-calibration..... which is the technical discussion point. As for specifically motor driven closed loop servos ( AF lenses with attached cameras), the system itself has 2 sources of inherent electronic error... Digital or D/A Servo loop step size and motor hysteresis. An analogy.. What is the most precise 12 hour timepiece in the world? A stopped clock. It is always 100% accurate twice a day. Ain't no such thing as zero tolerance. And it drifts. Frank Filippone Red735i at verizon.net <<< Closed-loop focussing algorithms would go a long way toward fixing the errors. Doug Herr