Since acquiring the 100-400 IS II a few months ago and pairing it up with the Canon 1.4 Extender III, many of my shots are out of focus. Attached is a screen capture showing my focus points which are spot on yet the image shown is improperly focused.
The extender was recently checked by Canon Service Center and no issues were found. The 5D Mark III and the Canon 100-400 IS II USM lens together without the extender offer perfect shots - no issues at all. As soon as the extender is mounted only a handful of shots (between 5% and 10%) are usable.
This photo was taken at 1/500 Tv with partial metering, AI Servo, Case 1 (of 6), Image Stabilization "On", obviously Point Expansion vs. Single Shot, Camera firmware is latest at 1.33, FE Lock "off".
After thinking this through, I do recall reading that in some cases, having IS "on" beyond the focal length could cause focus issues. However I do not have an issue with IS "on" beyond focal length "without the extender". I've yet to try IS "off" with extender on as my plans are to do so but curious outside of this, has anyone else with this same combo experienced these issues? My more immediate concerns are apparent issues with these 3 together: the 5D Mark III, 1.4 vIII extender and the 100-400 IS II USM - anyone else have this combo and experiencing similar issues? - thanks in advance
The extender was recently checked by Canon Service Center and no issues were found. The 5D Mark III and the Canon 100-400 IS II USM lens together without the extender offer perfect shots - no issues at all. As soon as the extender is mounted only a handful of shots (between 5% and 10%) are usable.
This photo was taken at 1/500 Tv with partial metering, AI Servo, Case 1 (of 6), Image Stabilization "On", obviously Point Expansion vs. Single Shot, Camera firmware is latest at 1.33, FE Lock "off".
After thinking this through, I do recall reading that in some cases, having IS "on" beyond the focal length could cause focus issues. However I do not have an issue with IS "on" beyond focal length "without the extender". I've yet to try IS "off" with extender on as my plans are to do so but curious outside of this, has anyone else with this same combo experienced these issues? My more immediate concerns are apparent issues with these 3 together: the 5D Mark III, 1.4 vIII extender and the 100-400 IS II USM - anyone else have this combo and experiencing similar issues? - thanks in advance