[Jack.L]

各位前輩想問o下人像攝影景深問題:
大光圈可以做到淺景深效果
但點先至可以做到恰到好處o既景深效果
好似用50mm 1.8/f
用1.8/f大約要用幾多快門
好似80-200mm 2.8/f
用2.8/f大約要用幾多快門
請各位指點小弟迷津...

[neu]

you can use the "stop down" function of your camera to check the aperture that you are shooting at.
most cameras have this function to check depth of field. eg. if you shoot at f8, and the maximun aperture of your lense is f2.8. you press that "stop down" button, then you'd see the view finder being darker at f8, instead of the max f2.8. you'd see how blurry the image is and if you need to adjust the aperture before pressing the shutter.
check your camera manuel, this function should be there. for canon, the function should be in "custom function" and the older models like canon new f1, there is a special knob near the lens mount for "stop down".
hope that could help, enjoy.

[neu]

sorry i forgot the second part of your question.

for NORMAL correct exposures, you need to take shutter speed and aperture into considerations. if you need to fix the aperture to f1.8, then just check the exposure value (ev) and see what you can match with f1.8.

you could use a grey card to check the ev. grey cards reflects 18% light. place the grey card 2-3 ft in front of your lense as the same angle that you are about to shoot, then check the meter to adjust the aperture and shutter speed. just shoot. you'd always get a correct exposure at most circumstances with this technique. remember, the light source should be from your back, don't use this technique to shoot AT light source (背光)

[747]

can DC (Canon A60) make this effect?
i tried f2.8 , zoom or no zoom, still everything clear !!!
pls help

[sevensister]

回 Jack L.

要控制景深的深淺
初學用 A mode 光圈先決模式 已經可以了
光圈值改變的同時
相機會自動調整快門速度作出配合
簡單又方便

回 747
DC (eg A60) 的 CCD 面積太小了
一般只有傳統菲林的 1/16 至 1/32
而且配合的鏡頭實際焦距太小
一般只有 5mm 至 20mm
除非應用在微距攝影
否則不可能有淺景深效果