[BKK]

請教多位C兄，Canon 常常被人話有走焦問題，好多人都怕怕，要更換system.

其實Canon的走焦問題近年有冇改善？ 是否配新出的Lens 會好D? 點解其它牌子冇人話有走焦問題？

請問有冇人發現以下的組合有走焦問題？

A: 40D + 17-55 2.8 IS
B: 40D + 17-40 4.0
C 40D + 25-105 4.0 IS
D 40D + 70-200 4.0 IS

Canon 机配其它副廠lens 的走焦問題是否更差？

[cy001]

I have 40D + EFS60mm f2.8 + EF 17-40mm f4.0L + EF 70-200mm f2.8 IS + EF 70-300 f4.0-5.6 DO IS. But all of them have not any 走焦問題.

[cy001]

Maybe tell u 走焦 only happened in Canon is another band's users. If it occured many many of this problems, it will not so many people to use it. The previous messgae have talked the reason why it's happened. if u chose EOS 1 Mark III, it have a function to fine tune the focus.

[cy001]

為了加強對焦的準確性，1D Mark III 特別加入了用戶自行調焦功能，用家可設定所有鏡頭使用相同的偏移量或是針對特定的鏡頭進行調整，相機可記憶 20 支以上的不同鏡頭，不過同款鏡頭便有可能要作不同的調整。筆者用作測試的兩支鏡頭 EF 16-35mm f/2.8L II USM 及 EF 70-200mm f/2.8L USM 對焦基本上都相當準確，所以並未需要用到此功能。

[tam_dominic]

A: 40D + 17-55 2.8 IS
B: 40D + 17-40 4.0
C 40D + 25-105 4.0 IS
D 40D + 70-200 4.0 IS

應無大問題.
大光圈時 如F1.8, F1.4 比較易察覺.

[gwu1]

thanks.

do you know why "大光圈時 如F1.8, F1.4 比較易察覺"?

[tam_dominic]

大光圈時 如F1.8, F1.4 中焦範圍小(景深小) 比較易察覺

[gwu1]

i see, thank you.

[nfever]

有時走左焦自己都唔知.
因為自己一直用開走焦機.

不過話時話 C記由 10D--->20D -- > 30D---> 40D 出到第4代都比人懷疑呢個問題, 真係幾收家!!

[orabuln]

不過話時話 C記由 10D--->20D -- > 30D---> 40D 出到第4代都比人懷疑呢個問題, 真係幾收家!!

咁走焦關部機定關枝鏡事...?

[nfever]

咁你要 search 番之前的 post, 大把.
兩樣都關事.

[orabuln]

鏡同機都係咁... canon 真係收家...

[lopddy923]

我想好多人都有上公司查詢過此問題，往往sales 都話無問題，唔通無問題問走去捉人錯處，canon又唔去面對去解決問題，出佐幾款都係用一毛病，賺用家大錢就算，唔去改進。

[gwu1]

i wonder whether other brands have 走焦 problem? i guess they would have the same problem too.

[tam_dominic]

I guess Can0n prefers the focusing speed (easy to know) and gives up the focusing accuracy (only know in shallow depth of field)

It is therefore most people rave the USM focusing speed and few complain the focus accuracy.

You'll find slower but more accurate focusing in other brands.