Hey guys,
I got a new DA 60-250 in recently, and I'm trying to check and calibrate the auto-focus with the fine adjustment tool.
I followed this blog post to set up the testing:
Jeffrey Friedl's Blog (I made a 0% gray version because i could focus on even the 5% gray!)
I noticed that at 60mm, the lens front-focuses, and at 200mm+ it back-focuses. In general though, it's also fairly inconsistent. Thinking it might be the camera (this was my first big AF tuning venture), I tried out my FA77 and DFA100 - both needed small adjustments, but they were both rock solid on consistency. So - it's not the camera. The only other factor that might have been affecting things was that my battery was getting quite low (red).
So my questions:
1) Is a front-focus at 60mm and back-focus at 200mm+ correctable besides at a repair shop?
2) Is SDM affected by low battery (more-so than the in-body motor used with FA77 and DFA100)?
3) Side question: When making AF fine adjustments, does the "all" offset affect lenses that have individual offsets set? E.g., if my DFA100 has "all" set to -3 and "individual" set to +2, is the camera doing -1 or +2?
Thanks guys!