[joe2728]

c兄...我有支70-200想影遠小小.是否加增距镜就ok架.
thx 小弟新手

[viovanda]

是

[joe2728]

咁係點分.點計架.thx c兄

[Obi-Wan]

Canon 70-200/F2.8, 4 IS or without IS, the best converters are
Extender 1.4X or 2.0X version I or II both ok

[kent_wks]

嘩！咁如果我部機本身個焦距換算比率已經係1.6，再加埋個增距咪大咗好多！
假使係2.0x，咁支70-200會變成幾大呀？

[mcsing]

1.4X = F2.8 >F4.0

2.0X = F2.8 >F5.6

[Obi-Wan]

"嘩！咁如果我部機本身個焦距換算比率已經係1.6，再加埋個增距咪大咗好多！假使係2.0x，咁支70-200會變成幾大呀？"

For 2X on little white (70-200mm/F2.8) on full frame (diagonal angle of view, f no.)
70 mm (~34°, f2.8) => 140 mm (~17°, f5.6)
200 mm (~12°, f2.8) => 400 mm (~6°, f5.6)

For 2X on little white (70-200mm/F2.8) on APS-C CANON (diagonal angle of view, f no.)
70 mm (~23°, f2.8) => 140 mm (~23°, f5.6)
200 mm (~8°, f2.8) => 400 mm (~4°, f5.6)

[lmichael]

質素會有影響, 出來的影像會差o左. 我有一舊, Kenko 2X. 用o左, 對焦會慢o左, 照片的質素都會差o左, 無用好耐.

[Obi-Wan]

If using CANON EXTENDER 2X, the quality is much better than Kenko 2X

please go to
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=103&Camera=9&Sample=0&FLI=6&API=4&LensComp=113&CameraComp=9&SampleComp=0&FLIComp=4&APIComp=3

to check a comparison between 70-200/2.8IS+Extender 2X vs 100-400/4.5-5.6 @ f8

[kent_wks]

唔該晒Obi-Wan師兄！