[gilbert622]

例如50L,85L都沒有IS,為什麼新百微又有IS? 唔該各位c hing.

[seamonkey]

我都好想知？百微以上就好多都有，是否鏡頭短做唔到呢？

[h0001244]

If you consider the safe shutter speed = 1 / focal length

for 24L 35L 50L 85L, with F1.2 or F1.4you can easily get shutter speed of 1/24 1/35 1/50 1/85 or above
for case slower 1/10, you will probably use tripod and seldom professional L users would believe the IS can help in such situation

Therefore, the situation that IS helps is rare with those big apetures....
or not worth to pay extra 3~4k for a seldom used function

Macro lens and tele-lens or tele zoom can easily get shutter speeds slower than safe shutter speed... that shake is quite significant in Macro as well.....
Compare 50L F1.2, 100L is having F2.8 only. 100L will easily fall into slower shutter speed lower than 1/100.....then the IS becomes more useful.............that makes people willing to pay 3~4k for IS

[seamonkey]

多謝h0001244師兄！

[gilbert622]

thanks

[叮噹仔]

同埋可以減低鏡身重量,
成本,
以及相片質數,
IS會少量減低相片質數,
(HIS我唔知)
因為賣sharp既定焦鏡,
唔想有一個破壞性既function.

[tam_dominic]

以下節錄自 "攝影基礎訓練" notes
=========================================================
7. 微距鏡
.......
當放大到 1:1時, 進入光量會減少約2級. Eg F2.8 1/60 變成 F2.8 1/15
.......
=========================================================
所以微距鏡 加 IS 很有意思.

[叮噹仔]

以前既微距, 都會用腳架加持,
不過風係最大既殺手,

呢家多左IS, 係某d環境下, 手持變成可行,
不過換黎既就係金錢既出走.