"f" la viet tat cho F-stop. F-stop chi muc do depth of field. So cang to thi do cang nho.
(vi du neu chi de F4 thi se nhieu depth of field hon de F8)
15''-1/2000 la chi shutter speed, tuc la thoi gian lense cua may mo ra, dua anh sang tiep xuc voi film. VD: 15'' la rat cham, lense mo trong 15 seconds. 1/2000: chac day la toc do mo lense toi da cua may (chi 1/2000 giay). Neu toc do mo may nhanh thi anh sang vao it (anh toi). Tuy nhien de capture a moment thi van phai dung high shutter speed (vi du em chup spray cua mot lo nuoc hoa de tu 1/500 -1/1000). Chinh vi de speed cao, anh co kha nang bi toi, vi the phai bu` lai bang cach ha. f-stop xuong (so cang to cang toi).
Thong thuong chi co the cam may= tay khi shutter speed tu 1/60 tro len. Neu de duoi 1/60 (vi du 1/30-15sec) nen dung tripod ko anh se bi nhoe.
Chi chup ngoai troi thi cung tuy nua, ko co cach xac dinh chuan nao la dung f-stop hay shutter speed bn. Tren ma'y co (manual hoan toan) thuong co light meter la mot cai meter co the nhin thay no di chuyen huong ve phia + (qua sang) hoac - (thieu sang). Neu chup khi light meter o giua hai cai +, - ay la tot nhat.
Con o may semi-manual thong thuong neu chi an nhe len cai button chup, nhin vao trong, se thay hien ra 2 thong so: f-stop va shutter speed. Neu chi muon co dinh shutter speed chang han, ma thay so chi f-stop nhap nhay, co nghia la dang thieu sang.
Cai ISO em ko biet lam, nho anh Hung giai dap tiep
