Sigma 500mm F4 DG OS HSM Sport - teleconverter AF issues?

Started Jan 3, 2019 | Questions thread
ManosSKG New Member • Posts: 17
Re: Update Re: Sigma 500mm F4 DG OS HSM Sport - teleconverter AF issues?

He does say that he solved it by 90% though. As I have personally contacted Brad Hill on this issue, he honored me his his reply and insisted that precise calibration is important. He also mentioned that he went to the PF, due to the weight advantage and as he was mainly shooting the sigma at 5.6, but not due to any AF issue.

I never used a Sigma that doesn't need fiddling, some more than others. My copy was severely focus shifting (only 1 in 3 shots sharp) and I brought the lens to a fine balance throughout the range with more than 90% keeper rate (ie at par with OEM glass). I find calibrating using visual aids, not adequate though (ie sloped rulers etc). I use my in camera auto FT system in combination with the dock. I change my figures in the dock and use the auto FT system as a reference point until I get a 0 to 1-+ value. Steve Perry's target works fine. So for anyone that owns the lens and af shifting persists, my tip is that you should persist as well and fine tune until you are happy. This thing does get resolved by 90-95%, but MFT adjustments must be precise.

 ManosSKG's gear list:ManosSKG's gear list
Nikon D500 Sigma 150-600mm F5-6.3 | C Sigma 500mm F4 Sport
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow