[canonboy]

請問要突出主題,光圈係咪要越細??
咁邊部有最優性光圈?

[yinyeah]

on the contrary, you need the largest possible aperture (smallest f number).

[marco_004]

I think you're wrong, if you want to have such effect, you should use large aperture, eg F2.0, F1.8.....

In all dc the market, Olympus 5050 has the largest aperture, ie upto F1.8.

[canonboy]

咁得F2.8咪好難突出主題?

[marco_004]

In DC (not D-SLR), It is difficult anyway, even you are using F2.0 such large aperture. If you are willing to have such effect, you such use the large aperture together with long focus distance.

[Briancat]

Yes, I agree. You need to use f2.0 or 2.8 and set a faster shutter speed (depends on environments).

[canonboy]

"不支援光圈先決" 意思=冇手動光圈?

[kiuchu]

光圈先決指：用者自設光圈，快門由相機決定。

[arts]

你講的主題太廣范，好難答你，車又係主題，棟樓又係主題，只狗又係主題，人象又係主題，所以一定要有具體項目作主題。
至于物體越大，光圈相對可以大D，如果拍攝人象，只突出面部，景深當然淺D好，使人象背景糢糊些，當然光圈越大效果會突出，但除光圈大之外，人象離背景不能太近，加上ZOOM遠些少拍，即係最少用80mm以上鏡頭，如果用35mm鏡以下，光圈開到1.2，效果亦不會好，如果拍狗仔，很難要牠坐定拍，光圈太大，景深自然會淺，很難撲捉到主題很清淅相片，小朋友也同樣情况，光圈自然對相對細D，相機對焦速度也要夠快，快門相對也要加快。

[canonboy]

thanks your reply ar~~!!
um....I mean 主題係人象ar.... If I use A70...how can take a good photo ar?