[老新]

我是用500d...見一d ching話 aps-c 因為唔係ff所以鏡頭是要ｘ多1.6
例如　２４－１０５＝３８．４－１６８．
２４呢個數字是代表什麼．最近距離？
１０５是最遠距離？
１７－４０＝２７－６４．．用係５００ｄ會唔夠ｗｉｄｅ．
CHING 可以解釋一下嗎．．真的攪到頭都大．．

[tam_dominic]

神鏡(Zoom Lens) 可以改變焦距 (Focal length) 以 milli-meter (mm) 做單位.
eg. 24mm -105mm , 17-40mm

[ck_112]

呢D數字係指 focal length.

[h0001244]

24-105mm is focal length
also representing the angle of view

As aps-c is smaller than Full frame, therefore
50mm on aps-c is having same angle as 80mm on FF

therefore we say there is Focal Length Multiplier of 1.6x on Canon Aps-c camera, 50mm x 1.6 = 80mm



24mm x 1.6 = 38.4mm (equivalent view angle on FF)
50mm x 1.6 = 80mm (equivalent view angle on FF)

[老新]

數字再X 大1.6 ..後 點解反而是說 唔夠WIDE呢.唔明.?
數字不是大了嗎.?.
新手..不要罵我笨 - -"

[henrynghc]

數字越細-越wide 如10-20 wide 鏡
數字越大-zoom得越遠 如100-400 長砲

[老新]

明白晒 thx