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Forums · Photo Gear Discussion

100-400mm with extender= no autofocus

Discussion

2 replies
Posted by Eirini Pajak on December 21, 2011 at 5:16 PM
I have a 5DMk2 and a 100-400mm f5.6 lens. The 1.4 & 2x extenders do not autofocus with this combination. Does anyone focus manually when photographing wildlife any more? I am trying to find out if getting an extender is worth it. Can't afford or carry the bigger lenses!
Posted by Floris van Breugel on December 21, 2011 at 6:34 PM
I wouldn't recommend putting a teleconverter on the 100-400 for a wide variety of reasons. You might consider the 400 prime with a teleconverter with the pins taped. Just place a thin strip of insulating tape over the three pins on the lefthand side (looking at the lens side of the converter). (That'll work with the 100-400, but you won't like the results).
Posted by Mark Seaver on December 26, 2011 at 9:51 PM
I use the 400 f/5.6 regularly with my 5D. When I add the 1.4 extender, it doesn't autofocus...not enough light at f/8. Since I'm not trying to shoot flying birds, manual focus works fine, but I had to go to a sturdier tripod (rated for 17 lbs) for that combo. With a tripod rated for 11 lbs, I was only getting about 50% of my shots sharp.