[K_C]

點解會有閃光燈同步速度呢?

如400d開左此function, 快門立即升為1/200秒, 點解要1/200秒唔1/100, 1/400或其他秒?

理論上1/200秒就已經就不會有手震情況出現, 就算鏡頭是否有IS已不再重要了.

[micros]

講緊咩曝光程式﹖

參考:
http://www.photozone.de/3Technology/flashtec5.htm

[Rol]

理論上1/200秒就已經就不會有手震情況出現

----------------------------------------

1/200 is very slow for 500mm lens, per traditional safe shutter speed, should be at least 1/500 sec for 500 mm lens.

Why need has X-flash syn shutter ? because the mechancial shutter in camera has maximum speed it can syn with flash, faster than this speed part of photo will not get the flash light,

However this max flash syn speed may not exactly at 1/500, 1/250, 1/125. If max syn speed at 1/180 and if shutter without this shutter step , then you are force to use slower 1/125 sec.

[bb1032003]

K C,

Don't worry you are Canon user and new EX speedlite has a high speed syn. You can use any shutter speed to syn, but the output is less.

Go to check with the speedlite.

[vaworld]

閃燈主要唔係靠快門速度凝固動作.
係靠閃燈本身 duration(可以低過1/10000sec).
當然係要現場光比例低.
若果現場光度比例高, 快門速度就要較高為好.

[K_C]

多謝各高人指教~~

問題係我用AV mode拍照, 一樣開住支外閃, 用同一iso, 同一光圈, 但唔同快門, 一個係機自己set, 一個就用同步速度, 即1/200秒, 但兩張相出來都無太大光暗分別 (可能肉眼睇唔出) 既然1/200秒怏門可以抵銷手震, 咁點解唔可以張張都用呢個方式影呢??

[vaworld]

如果主要光源係閃燈, 當然唔同快門唔會有太大分別.

[K_C]

"如果主要光源係閃燈, 當然唔同快門唔會有太大分別. "??

點解呢? 快門1/4秒一定比1/200秒慢, 入光照計都會多, 何出此言呢?

[micros]

環境係唔係好光下﹖
唔用閃同用閃o既快門分別係 ...... ﹖

[fokkp]

如果主要光源係閃燈, 當然唔同快門唔會有太大分別. "??
點解呢? 快門1/4秒一定比1/200秒慢, 入光照計都會多, 何出此言呢?


用 A Mode
快快門，目標物清（焦點），后面暗。
慢快門，連后面都清（太遠除外）。

[vaworld]

背景光越弱, 快門影響越小
背景光越強, 快門影響越大

若果你發覺快門無大影響就即係話背景光對比閃光唔算強.

[vaworld]

重有係光圈不變!

[six_seven]

最簡單講,當用閃光燈時,光圈不變情況下,快門係影響緊背景光暗,光圈及閃光燈就影響前景或主體光暗.

PS:當然光圈大細都同時影響緊背景光暗及景深!