{"id":18657,"date":"2014-12-03T11:29:43","date_gmt":"2014-12-03T04:29:43","guid":{"rendered":"https:\/\/banbientan.com\/?p=18657"},"modified":"2014-12-03T11:29:43","modified_gmt":"2014-12-03T04:29:43","slug":"nguyen-ly-co-ban-cua-chieu-sang","status":"publish","type":"post","link":"https:\/\/hunglong.banbientan.com\/?p=18657","title":{"rendered":"Nguy\u00ean l\u00fd c\u01a1 b\u1ea3n c\u1ee7a chi\u1ebfu s\u00e1ng"},"content":{"rendered":"

S\u1ef1 h\u1ea5p th\u1ee5 v\u00e0 ph\u1ea3n x\u1ea1 \u00e1nh s\u00e1ng\"nguon<\/a><\/strong><\/h3>\n

Khi c\u00f3 \u00e1nh s\u00e1ng chi\u1ebfu v\u00e0o m\u1ed9t b\u1ec1 m\u1eb7t, n\u00f3 s\u1ebd b\u1ecb h\u1ea5p th\u1ee5 ho\u1eb7c ph\u1ea3n x\u1ea1.
\nTrong h\u1ea7u h\u1ebft c\u00e1c tr\u01b0\u1eddng h\u1ee3p, c\u1ea3 hai qu\u00e1 tr\u00ecnh h\u1ea5p th\u1ee5 v\u00e0 ph\u1ea3n x\u1ea1<\/strong><\/b> \u0111\u1ec1u x\u1ea3y ra, t\u1ea1o n\u00ean s\u1ef1 \u0111a d\u1ea1ng c\u1ee7ac\u01b0\u1eddng \u0111\u1ed9 s\u00e1ng <\/strong><\/b>v\u00e0 \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n<\/strong><\/b>.
\nS\u1ef1 ph\u1ea3n x\u1ea1 \u00e1nh s\u00e1ng c\u00f3 th\u1ec3 d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c, v\u00e0 s\u1ef1 \u1ea3nh h\u01b0\u1edfng c\u1ee7a \u00e1nh s\u00e1ng l\u00ean \u1ea3nh c\u1ee7a camera c\u0169ng c\u00f3 th\u1ec3 d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c.
\nVi\u1ec7c \u0111i\u1ec1u khi\u1ec3n c\u00e1c qu\u00e1 tr\u00ecnh n\u00e0y l\u00e0 ch\u00eca kh\u00f3a \u0111\u1ec3 th\u1ef1c hi\u1ec7n th\u00e0nh c\u00f4ng qu\u00e1 tr\u00ecnh nh\u1eadn d\u1ea1ng \u0111\u1ed1i t\u01b0\u1ee3ng.<\/p>\n

G\u00f3c ph\u1ea3n x\u1ea1\"goc
\n<\/strong><\/h3>\n

\u00c1nh s\u00e1ng ph\u1ea3n x\u1ea1 m\u1ed9t g\u00f3c c\u00f3 \u0111\u1ed9 l\u1edbn b\u1eb1ng v\u00e0 ng\u01b0\u1ee3c v\u1edbi g\u00f3c t\u1edbi. H\u00e3y nh\u00ecn v\u00e0o 2 v\u00ed d\u1ee5 b\u00ean c\u1ea1nh v\u00e0 x\u00e1c \u0111\u1ecbnh g\u00f3c t\u1edbi(m\u00e0u \u0111\u1ecf)<\/span> v\u00e0 g\u00f3c ph\u1ea3n x\u1ea1 (m\u00e0u xanh).<\/span>
\nS\u1ef1 kh\u00e1c nhau gi\u1eefa h\u00ecnh d\u1ea1ng b\u1ec1 m\u1eb7t c\u1ee7a \u0111\u1ed1i t\u01b0\u1ee3ng c\u1ea7n nh\u1eadn d\u1ea1ng s\u1ebd quy\u1ebft \u0111\u1ecbnh c\u01b0\u1eddng \u0111\u1ed9 s\u00e1ng c\u1ee7a \u00e1nh s\u00e1ng ph\u1ea3n x\u1ea1.
\nC\u00e1c bi\u1ebfn m\u00e0 ta c\u1ea7n qu\u1ea3n l\u00fd \u0111\u1ec3 \u0111i\u1ec1u khi\u1ec3n s\u1ef1 ph\u1ea3n x\u1ea1, v\u00e0 t\u1eeb \u0111\u00f3 \u0111i\u1ec1u khi\u1ec3n h\u00ecnh \u1ea3nh l\u00e0 l\u1ef1a ch\u1ecdn ngu\u1ed3n s\u00e1ng <\/strong><\/b>v\u00e0 v\u1ecb tr\u00ed ngu\u1ed3n s\u00e1ng<\/strong><\/b>.<\/p>\n

\u0110\u1ed9 t\u01b0\u01a1ng ph\u1ea3n<\/strong><\/h3>\n\n\n\n\n
K\u00e9m<\/strong><\/td>\nT\u1ed1t<\/strong><\/td>\n<\/tr>\n
\"do<\/td>\n\"do<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Y\u1ebfu t\u1ed1 \u0111\u1ea7u ti\u00ean khi thi\u1ebft k\u1ebf chi\u1ebfu s\u00e1ng m\u00e0 ta c\u1ea7n th\u1ef1c hi\u1ec7n l\u00e0 \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n.<\/strong><\/b>
\n\u00c1nh s\u00e1ng ph\u1ea3i t\u1ea1o ra \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n cao nh\u1ea5t gi\u1eefa c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng c\u1ea7n \u0111\u01b0\u1ee3c nh\u1eadn d\u1ea1ng v\u00e0 c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng kh\u00e1c \u1edf trong c\u00f9ng m\u1ed9t khu v\u1ef1c.
\nC\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng c\u1ea7n \u0111\u01b0\u1ee3c nh\u1eadn d\u1ea1ng c\u1ea7n ph\u1ea3i \u0111\u01b0\u1ee3c n\u1ed5i b\u1eadt so v\u1edbi c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng kh\u00e1c trong v\u00f9ng quan s\u00e1t (FOV).<\/strong><\/b><\/p>\n

C\u01b0\u1eddng \u0111\u1ed9 s\u00e1ng\"cuong<\/a><\/strong><\/h3>\n

C\u01b0\u1eddng \u0111\u1ed9 s\u00e1ng l\u00e0 l\u01b0\u1ee3ng \u00e1nh s\u00e1ng t\u1ea1o ra b\u1edfi ngu\u1ed3n s\u00e1ng. Khi v\u1eadn h\u00e0nh, ta n\u00ean s\u1eed d\u1ee5ng v\u1edbi c\u01b0\u1eddng \u0111\u1ed9 v\u1eeba \u0111\u1ee7 v\u1edbi y\u00eau c\u1ea7u \u0111\u1ec3 t\u1ea1o ra \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n t\u1ed1t.
\nN\u1ebfu c\u01b0\u1eddng \u0111\u1ed9 s\u00e1ng qu\u00e1 cao, h\u00ecnh \u1ea3nh c\u00f3 th\u1ec3 b\u1ecb l\u00f3a v\u00e0 \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n gi\u1ea3m. M\u1eb7t kh\u00e1c, n\u1ebfu c\u01b0\u1eddng \u0111\u1ed9 s\u00e1ng qu\u00e1 y\u1ebfu, h\u00ecnh \u1ea3nh s\u1ebd b\u1ecb t\u1ed1i v\u00e0 kh\u00f4ng nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c.H\u00e3y nh\u00ecn h\u00ecnh t\u1ee5 \u0111i\u1ec7n m\u00e0u xanh \u0111\u1ec3 th\u1ea5y \u0111\u01b0\u1ee3c s\u1ef1 kh\u00e1c bi\u1ec7t trong vi\u1ec7c \u0111i\u1ec1u ch\u1ec9nh c\u01b0\u1eddng \u0111\u1ed9 s\u00e1ng.
\nC\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a \u00e1nh s\u00e1ng ph\u1ea3n x\u1ea1 c\u00f3 th\u1ec3 thay \u0111\u1ed5i ch\u1ec9 v\u1edbi m\u1ed9t s\u1ef1 thay \u0111\u1ed5i nh\u1ecf c\u1ee7a m\u00f4i tr\u01b0\u1eddng, \u0111i\u1ec1u n\u00e0y d\u1eabn \u0111\u1ebfn vi\u1ec7c h\u00ecnh \u1ea3nh c\u1ee7a \u0111\u1ed1i t\u01b0\u1ee3ng kh\u00f4ng \u0111\u01b0\u01a1c \u1ed5n \u0111\u1ecbnh.
\nCh\u00fa \u00fd:\u00a0<\/strong>N\u1ebfu khu v\u1ef1c ki\u1ec3m tra c\u00f3 c\u00e1c ngu\u1ed3n s\u00e1ng c\u00f4ng nghi\u1ec7p (HPS,
\n\u0111\u00e8n th\u1ee7y ng\u00e2n, \u0111\u00e8n hu\u1ef3nh quang) , c\u1ea7n m\u1ed9t ngu\u1ed3n s\u00e1ng v\u1edbi c\u01b0\u1eddng \u0111\u1ed9<\/p>\n\n\n\n\n
\"cuong<\/td>\n<\/tr>\n
C\u01b0\u1eddng \u0111\u1ed9 \u00e1nh s\u00e1ng t\u1eeb th\u1ea5p \u0111\u1ebfn cao<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

cao h\u01a1n \u0111\u1ec3 h\u1ea1n ch\u1ebf hi\u1ec7u \u1ee9ng t\u1eeb c\u00e1c ngu\u1ed3n s\u00e1ng n\u00e0y \u0111\u1ebfn \u0111\u1ed1i t\u01b0\u1ee3ng. Ch\u00fang ta c\u0169ng n\u00ean l\u1eafp th\u00eam c\u00e1c l\u1edbp v\u1ecf b\u1ea3o v\u1ec7 c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng n\u00e0y \u0111\u1ec3 tr\u00e1nh \u1ea3nh h\u01b0\u1edfng n\u00f3i tr\u00ean.
\nN\u00ean s\u1eed d\u1ee5ng c\u00e1c ngu\u1ed3n s\u00e1ng c\u00f3 c\u00f4ng su\u1ea5t l\u1edbn h\u01a1n m\u1ee9c c\u00f4ng su\u1ea5t s\u1eed d\u1ee5ng th\u01b0\u1eddng xuy\u00ean v\u00ec n\u1ebfu c\u00e1c ngu\u1ed3n s\u00e1ng ho\u1ea1t \u0111\u1ed9ng v\u1edbi c\u00f4ng su\u1ea5t t\u00f4i \u0111a trong m\u1ed9t th\u1eddi gian d\u00e0i, l\u01b0\u1ee3ng nhi\u1ec7t sinh ra s\u1ebd l\u00e0m gi\u1ea3m tu\u1ed5i th\u1ecd c\u1ee7a ch\u00fang.
\nVi\u1ec7c s\u1eed d\u1ee5ng ngu\u1ed3n s\u00e1ng v\u1edbi c\u01b0\u1eddng \u0111\u1ed9 qu\u00e1 b\u00e9 c\u0169ng s\u1ebd g\u00e2y n\u00ean nhi\u1ec1u v\u1ea5n \u0111\u1ec1 v\u1edbi chi\u1ec1u s\u00e2u \u1ea3nh DOF (Depth of Field) v\u00e0 l\u00e0m nhi\u1ec5u t\u00edn hi\u1ec7u \u1edf camera.
\nVi\u1ec7c \u0111i\u1ec1u ch\u1ec9nh s\u1ebd \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh d\u1ef1a theo \u0111\u1ed1i t\u01b0\u1ee3ng m\u00e0 ch\u00fang ta mu\u1ed1n ki\u1ec3m tra.<\/p>\n