[jeffrey_sam]

各位CHING 我想問如果　１００﹣４００　加了增距鏡　2x，　是否還有 auto focus. Thanks.

[s82011190]

Canon CS 話 X 2之後光圈小過 8 就無auto focus

[飛哥仔]

唔係5.6咩? =.=

[jeffrey_sam]

即係 100 - 400 只可以用 x1.4 ?
5.6 x 1.4 = 7.84
Is that right?

[speedstar]

No...both 1.4x and 2x can be used.
But with 1.4x stilll have AF, 2.0x no AF

[look_yau]

用 1DM3/4 就F8都仲可以用中間個點

[jeffrey_sam]

Thanks all ching

[derekkwwong]

如果你用最新CANON　EXTENDER ２x 第三代好似有。不過去到Ｆ１１，都係唔好要求任何質素，影到有自動對焦已不錯。

[hotfire009]

Kenko 2x TC with tape covering the right three metal contact points still has AF with f/5.6 lens whereas CANON 2x TC does not work in tape trick.

[lumbak]

The image quality after attaching my 1.4x mark 2 extendor to 100-400mm becomes very poor even though i stop down the f-value . So I believe attaching 2x to 100-400mm and shoto at 400mm will not be good at all. Any minor manual focusing error will cause image out-focus. You better to shoot without the 2x and crop from the 400mm end la !