[kenneth_choi]

我部d 40 點解淨係得光圈先決既時候先可以揀慢速閃燈..而快門先決既時候就冇得揀呢? 唔明~

[arafeva]

common confusion

慢速閃光, which is Slow sync, is actually referred to slow shutter speed with when using flash.

that's why you wont have that option when you use 快門先決 as you are already controlling the shutter speed in the first place.

[kenneth_choi]

明白哂....thanks.