[Curtismnw]

仲有想問小白2+EF2X的對焦速度會否比大白慢？

[h0001244]

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&Camera=453&Sample=0&FLI=7&API=2&LensComp=113&CameraComp=453&SampleComp=0&FLIComp=7&APIComp=0

The result is very close already with Extender 2x III

[Marksman01]

both PQ and AF speed the BW is better than SW2+2x a bit

[lovezen1234]

呢個問題我上網搵左好耐, 發覺大白比小白2+2x pq 只係靚少少, 但當小白2+2x收到f8 後就好似無咩分別, 在對焦上, 小白2在有2x 與無2x既分別, 小弟係分別唔到速度下降, 但pq就明顯比無上2x 差, 起碼要收到f8先可以同無上2x既2.8 拉近距離, 但當加了2x後在low light 上, 會拉下風琴, 當出現呢個情況後,你要留意下枝鏡係switch 左 (好似係)0.8-1.2m 定係 1.2m-無限遠後, 調番後就唔會有呢個問題. 我係用2xiii的, 希望幫到你

[Nicku]

both PQ and AF speed the BW is better than SW2+2x a bit - Agreed