[MKV]

佢有1.4x同2.0x係咪只係遠近分別呢??

[bzboy]

1.4X is better to control.
All mm x 1.4 if use X2 it will very large.

[Obi-Wan]

1.4x lost one step in aperture, 2x lost two steps

if using 2x in 小小白， no AF unless in 1 series

[jenson123]

1.4X II is preferable

[calwkf]

1.4x 細一級光圈
2x 細兩級光圈

APS-C 最大支援有AF係 F/5.6

e.g. 小白 2.8 w/1.4x = 4 (AF normal) / w/2x = 5.6 (AF normal), 小小白 4 w/1.4x = 5.6 (AF normal) / w/2x = 8 (no AF)

[calwkf]

我去showroom試過, 覺得同副廠質數差唔多...

[Obi-Wan]

Optical quality extender 1.4X is better than extender 2X
I use 2X for traveling with 70-200/2.8IS, seldom use 1.4X

[MKV]

甘單講焦距枝55-250咪變左110-500囉?甘平均講55-250+1.4x都係$3xxx左右......平玩都應ok呵??

[Obi-Wan]

Canon is not designed for EFS 55-250, u will be sorry if mount on it!

[MKV]

係???個sales想昆我??

[Obi-Wan]

Other brand 1.4X or 2X may be mounted on 55-250, but CANON's extenders should not be mounter, otherwise..... your CANON extender 2X may be damaged

[wesleyyau]

Kenko d teleconverter 都mount 唔到ef-s 喎...
其實買之前最好自己check check 個teleconverter 個Compatibility List... 知道邊d鏡用得... 邊d 唔得... 會安全好多...

[h0001244]

So far from my experience
Canon Extender is designed for 135mm or above only...... those white lens + few black prime like 135F2 200F2.8
Kenko Extender can be applied to all EF Lens except the EF-s
kenko extender can be applied to Sigma, Tokina, Tamron aps-c lens, eg 10-17 fish okay but you won't need that

tried the tamron 18-200 on kenko 2X, I press the shutter half, but can't confirm focus even under bright sunlight at 1pm

[Obi-Wan]

wesleyyau

the front glass element of CANON extender may damage even EF lens because its front element is deeply inserted into the rear of your EF lens

[kk2828]

我想問下原廠的1.4 同副廠的1.4在畫質上分別大嗎?