[Panda1802]

各位Ching,
日前做了一個實驗,用下列四支鏡頭,即使是用相同的焦距(我以24mm段),影相同的東西(我是落腳,所以位置是不變),影出來的邊位的東西都有差別的(即視角不一樣),
Canon EF 24-105 (24段)
Canon EF-S 17-85 (24段)
Tamron 17-50 (24段)
Tokina 12-24 (24)
是否真的不同鏡頭,即使相同焦距,視角也不一樣?即使同是Canon也一樣如是

[sannaso]

yes,for example:sigma 50 1.4 is more wide than canon 50 1.4

[AlpinweissM]

I think the focal range is just an estimate, correct me if i am wrong

[seanlam1234]

"sigma 50 1.4 is more wide than canon 50 1.4 "

realy??? @_@

[sannaso]

http://www.dcfever.com/news/readnews.php?id=2861

[sannaso]

sigma just 49 mm

[Panda1802]

看完這個測試,Sigma真是wide一D
不過即使是同廠,也不一樣的.

[Obi-Wan]

All lens define the focal length AS DISTANCE AT INFINITY,
some lenses when focus on a 2m object will show bigger magification that other lenses with the same focal length because the first one uses a front element focusing mechanism so that the lens extend when focusing close object, a higher magnification results

[王迦南]

1. 廠商標示的焦距祇是一個近似值，實際焦距有1mm以內的誤差絕不為奇。因此，不同品牌而聲稱同一焦距的鏡頭會有不同的視角。


2. 更重要的是，除了魚眼鏡外，設計一般鏡頭時都會考慮作出變形矯正。不同的矯正方法和矯正的程度，便會對視角有更大的影響了。