[klwtony]

想請問我用500D+Extender EF 2x II
+Canon EF 70-200mm f/4.0 L USM
是不是沒有了自動對焦 而只能用手動對焦.

有無其他方法呀?

[ACanonGuy]

有自動對焦

http://www.bhphotovideo.com/FrameWork/charts/canon2xExtender.html

[klwtony]

Thx....will try again

[h0001244]

唔得呀，70-200 F4 + 2X 得番 F8，只有高級機種如 1仔先可 AF呀
550D會block左個AF function 的

不過道高一呎，魔高一丈
試想想，基於什麼唔俾你AF，係加了2X後將你的data由F4變F8，咁如果唔話.俾部聽係F8咪得囉
看看這個，原理差不多
http://atinyblip.com/articles/photography/kenko-2x-teleplus-pro-300-teleconverter/
不過有AF唔等於AF順，我試過18-250 + 2X 後係日光日白都對唔到焦的，只會搏命search的

[klwtony]

如果用7D會唔會得呢?我見到有人用7D好似有AF呀.

[klwtony]

請問如果用EF 1.4X II 又得唔得呀?
會唔會用到AF?
唔該

[h0001244]

7D 唔肯定

如無記錯，550D 應該係最多用到F5.6 ，(F4 + EF1.4X become F5.6) ，即係有AF

不過有趣的是 18-270 這類大陪zoom，最細光圈時係 F6.3，但係都有AF，我就真係唔明了

[Obi-Wan]

CANON extender2X can be used with F4 lens with AF in my 7D, 50D, 5D2, 20D by using aluminum foil to block the left 3 gold finger INSIDE THE EXTENDER TOWARDS THE LENS, the extender in this setting fools the camera as 1.4X, I used this on 384, 584, SSW without any problems on yhe above camera

happy shooting!

[Obi-Wan]