{"id":1381,"date":"2021-03-05T09:35:34","date_gmt":"2021-03-05T02:35:34","guid":{"rendered":"http:\/\/weathervn.com\/?p=1381"},"modified":"2021-03-05T09:35:58","modified_gmt":"2021-03-05T02:35:58","slug":"nhiep-anh-thien-van-va-cac-van-de-voi-nguoi-moi-choi-bai-1-2-tran-ha","status":"publish","type":"post","link":"https:\/\/vietweather.com\/index.php\/nhiep-anh-thien-van-va-cac-van-de-voi-nguoi-moi-choi-bai-1-2-tran-ha\/","title":{"rendered":"Nhi\u1ebfp \u1ea3nh thi\u00ean v\u0103n v\u00e0 c\u00e1c v\u1ea5n \u0111\u1ec1 v\u1edbi ng\u01b0\u1eddi m\u1edbi ch\u01a1i (B\u00e0i 1- 2) – Tr\u1ea7n H\u1ea1"},"content":{"rendered":"

2. \u00d4 nhi\u1ec5m \u00e1nh s\u00e1ng v\u1edbi nhi\u1ebfp \u1ea3nh thi\u00ean v\u0103n<\/strong><\/p>\n

C\u00f3 l\u1ebd kh\u00f4ng c\u1ea7n b\u00e0n nhi\u1ec1u t\u1edbi t\u00e1c h\u1ea1i c\u1ee7a \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng v\u00e0 \u1ea3nh h\u01b0\u1edfng ti\u00eau c\u1ef1c c\u1ee7a n\u00f3 t\u1edbi nhi\u1ebfp \u1ea3nh thi\u00ean v\u0103n. B\u1ea1n \u0111ang s\u1ed1ng gi\u1eefa trung t\u00e2m th\u00e0nh ph\u1ed1 l\u1edbn nh\u01b0 H\u00e0 N\u1ed9i hay H\u1ed3 Ch\u00ed Minh, b\u1ea1n mu\u1ed1n ch\u1ee5p \u0111\u01b0\u1ee3c nh\u1eefng b\u1ee9c \u1ea3nh tinh v\u00e2n \u201cth\u1ea7n s\u1ea7u\u201d nh\u01b0 tr\u00ean Google, \u0111\u00f3 l\u00e0 \u0111i\u1ec1u b\u1ea5t kh\u1ea3 thi. V\u00e0 kh\u00f4ng ch\u1ec9 c\u00f3 c\u00e1c th\u00e0nh ph\u1ed1 l\u1edbn, ngay c\u1ea3 nh\u1eefng khu v\u1ef1c ngo\u1ea1i \u00f4 tr\u00ean kh\u1eafp Vi\u1ec7t Nam c\u0169ng \u0111ang h\u1ee9ng ch\u1ecbu nguy c\u01a1 t\u01b0\u01a1ng t\u1ef1. Nhi\u1ebfp \u1ea3nh thi\u00ean v\u0103n kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t th\u00fa ch\u01a1i ph\u1ee9c t\u1ea1p, xa x\u1ec9 m\u00e0 c\u00f2n v\u00f4 c\u00f9ng k\u00e9n ch\u1ecdn!!<\/p>\n

C\u00e1c s\u1ed1 li\u1ec7u v\u1ec1 \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng th\u01b0\u1eddng d\u1ef1a v\u00e0o thang \u0111o Bortle, m\u1ed9t quy \u01b0\u1edbc \u0111\u01b0\u1ee3c c\u00f4ng nh\u1eadn r\u1ed9ng r\u00e3i b\u1edfi gi\u1edbi ch\u01a1i \u1ea3nh thi\u00ean v\u0103n nghi\u1ec7p d\u01b0 \u0111\u1ec3 m\u00f4 t\u1ea3 \u0111\u1ed9 s\u00e1ng c\u1ee7a b\u1ea7u tr\u1eddi \u0111\u00eam t\u1ea1i m\u1ed9t v\u1ecb tr\u00ed c\u1ee5 th\u1ec3. Thang \u0111o Bortle c\u00f3 9 m\u1ee9c, v\u1edbi m\u1ee9c 1 bi\u1ec3u th\u1ecb cho b\u1ea7u tr\u1eddi \u0111\u00eam l\u00fd t\u01b0\u1edfng v\u00e0 ho\u00e0n to\u00e0n kh\u00f4ng b\u1ecb \u1ea3nh h\u01b0\u1edfng b\u1edfi \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng. C\u00f2n m\u1ee9c 9 th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111o \u1edf nh\u1eefng n\u01a1i nh\u01b0 trung t\u00e2m c\u00e1c th\u00e0nh ph\u1ed1 l\u1edbn v\u1edbi m\u1eadt \u0111\u1ed3 \u0111\u00e8n \u0111\u01b0\u1eddng, \u0111\u00e8n qu\u1ea3ng c\u00e1o v\u00e0 \u00e1nh s\u00e1ng sinh ho\u1ea1t d\u00e0y \u0111\u1eb7c. H\u00e3y quan s\u00e1t h\u00ecnh d\u01b0\u1edbi \u0111\u00e2y \u0111\u1ec3 th\u1ea5y \u0111\u01b0\u1ee3c kh\u00e1c bi\u1ec7t t\u01b0\u01a1ng \u0111\u1ed1i gi\u1eefa c\u00e1c m\u1ee9c \u0111\u1ed9 \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng:<\/p>\n

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Thang Bortle t\u1eeb ph\u1ea3i qua tr\u00e1i theo th\u1ee9 t\u1ef1 \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng t\u0103ng d\u1ea7n. \u1ea2nh: SKYGLOW
\n<\/strong><\/p>\n

\"image-asset\"
\u00a0<\/strong><\/figcaption><\/figure>\n

C\u00e1c b\u1ea1n c\u00f3 th\u1ec3 t\u00ecm hi\u1ec3u v\u1ec1 thang \u00f4 nhi\u1ec5m t\u1ea1i n\u01a1i m\u00ecnh \u0111ang s\u1ed1ng d\u1ef1a v\u00e0o m\u1ed9t trong c\u00e1c b\u1ea3n \u0111\u1ed3 online sau:
\n\u2013\u00a0https:\/\/www.lightpollutionmap.info<\/a>
\n\u2013\u00a0https:\/\/darksitefinder.com<\/a>
\nHo\u1eb7c c\u00e0i \u0111\u1eb7t \u1ee9ng d\u1ee5ng di \u0111\u1ed9ng Clear Outside. M\u1ee9c \u0111\u1ed9 \u00f4 nhi\u1ec5m tr\u00ean thang Bortle s\u1ebd \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n tr\u00ean giao di\u1ec7n app.<\/p>\n

M\u1ee9c Bortle\u00a0d\u01b0\u1edbi 4<\/strong>\u00a0\u0111\u01b0\u1ee3c coi l\u00e0 l\u00fd t\u01b0\u1edfng cho nhi\u1ebfp \u1ea3nh thi\u00ean v\u0103n. Khi b\u1ea7u tr\u1eddi \u0111\u00eam trong tr\u1ebbo v\u00e0 \u00edt ch\u1ecbu \u1ea3nh h\u01b0\u1edfng b\u1edfi \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng, m\u00e1y \u1ea3nh s\u1ebd ph\u01a1i \u0111\u01b0\u1ee3c l\u00e2u h\u01a1n m\u00e0 kh\u00f4ng b\u1ecb d\u00ednh qu\u1ea7ng gradient ho\u1eb7c ch\u00e1y s\u00e1ng tr\u1ea7m tr\u1ecdng do \u00e1nh s\u00e1ng t\u1eeb m\u1eb7t \u0111\u1ea5t h\u1eaft l\u00ean. M\u00e0u s\u1eafc c\u00e1c thi\u00ean th\u1ec3 v\u00e0 b\u1ea7u tr\u1eddi s\u1ebd th\u1eadt h\u01a1n, d\u1ec5 d\u00e0ng khi x\u1eed l\u00fd h\u1eadu k\u1ef3.<\/p>\n

 <\/p>\n

B\u1ea7u tr\u1eddi m\u00f9a \u0111\u00f4ng \u0111\u1ea7y sao t\u1ea1i m\u1ed9t khu v\u1ef1c Bortle 4.<\/strong><\/p>\n

\"IMG_0960\"
\u00a0<\/b><\/figcaption><\/figure>\n

 <\/p>\n

V\u1edbi m\u1ee9c Bortle\u00a0tr\u00ean 5<\/strong>, \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng s\u1ebd l\u00e0m \u1ea3nh h\u01b0\u1edfng nghi\u00eam tr\u1ecdng t\u1edbi h\u00ecnh \u1ea3nh thu \u0111\u01b0\u1ee3c. Th\u00f4ng th\u01b0\u1eddng, n\u1ebfu kh\u00f4ng s\u1eed d\u1ee5ng c\u00f4ng c\u1ee5 h\u1ed7 tr\u1ee3, khu v\u1ef1c Bortle 6 th\u01b0\u1eddng ch\u1ec9 cho ph\u00e9p ph\u01a1i s\u00e1ng d\u01b0\u1edbi 1 ph\u00fat (ISO 1600 v\u1edbi kh\u1ea9u \u0111\u1ed9 F4) tr\u01b0\u1edbc khi \u1ea3nh b\u1ecb ch\u00e1y ho\u1eb7c \u00e1m v\u00e0ng n\u1eb7ng n\u1ec1 t\u1edbi m\u1ee9c kh\u00f4ng th\u1ec3 c\u1ee9u \u0111\u01b0\u1ee3c. Thang Bortle cao h\u01a1n, th\u1eddi gian ph\u01a1i s\u00e1ng c\u00e0ng ng\u1eafn l\u1ea1i, l\u00e0m gi\u1ea3m kh\u1ea3 n\u0103ng thu t\u00edn hi\u1ec7u c\u00f3 \u00edch t\u1edbi t\u1eeb c\u00e1c thi\u00ean th\u1ec3 t\u1ed1i.<\/p>\n

M\u1ed9t gi\u1ea3i ph\u00e1p g\u1ea7n nh\u01b0 duy nh\u1ea5t hi\u1ec7n gi\u1edd \u0111\u1ec3 \u0111\u1ed1i ph\u00f3 v\u1edbi t\u00ecnh tr\u1ea1ng \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng l\u00e0 k\u00ednh l\u1ecdc ch\u1ed1ng \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng. Nguy\u00ean t\u1eafc chung c\u1ee7a c\u00e1c lo\u1ea1i k\u00ednh l\u1ecdc n\u00e0y \u0111\u1ec1u kh\u00e1 t\u01b0\u01a1ng \u0111\u1ed3ng nhau, \u0111\u00f3 l\u00e0 t\u00ecm c\u00e1ch gi\u1ea3m b\u1edbt (l\u1ecdc b\u1edbt) nh\u1eefng b\u01b0\u1edbc s\u00f3ng d\u01b0 th\u1eeba tr\u01b0\u1edbc khi t\u1edbi sensor thu h\u00ecnh, ch\u1ec9 \u0111\u1ec3 l\u1ea1i ph\u1ea7n ph\u1ed5 ph\u00e1t x\u1ea1 c\u00f3 \u00edch t\u1edbi t\u1eeb c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng ch\u00ednh tr\u00ean b\u1ea7u tr\u1eddi. T\u00f4i d\u00f9ng t\u1eeb \u201cgi\u1ea3m b\u1edbt\u201d \u1edf \u0111\u00e2y l\u00e0 v\u00ec kh\u00f4ng c\u00f3 m\u1ed9t lo\u1ea1i k\u00ednh l\u1ecdc n\u00e0o c\u00f3 th\u1ec3 lo\u1ea1i b\u1ecf 100% \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng. Tr\u00ean th\u1ef1c t\u1ebf, c\u00f3 r\u1ea5t nhi\u1ec1u lo\u1ea1i \u0111\u00e8n s\u1edf h\u1eefu b\u01b0\u1edbc s\u00f3ng ph\u00e1t x\u1ea1 tr\u1ea3i r\u1ed9ng tr\u00ean m\u1ecdi v\u00f9ng ph\u1ed5 \u00e1nh s\u00e1ng m\u00e0 con ng\u01b0\u1eddi nh\u00ecn th\u1ea5y \u0111\u01b0\u1ee3c nh\u01b0 \u0111\u00e8n led tr\u1eafng, \u0111\u00e8n halogen kim lo\u1ea1i\u2026 Do \u0111\u00f3, kh\u1ea3 n\u0103ng b\u1ecb tr\u00f9ng ch\u1eadp ph\u1ed5 v\u1edbi c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng thi\u00ean v\u0103n tr\u00ean b\u1ea7u tr\u1eddi l\u00e0 c\u00f3 th\u1ec3 x\u1ea3y ra v\u00e0 m\u1eadt \u0111\u1ed9 nh\u1eefng lo\u1ea1i \u0111\u00e8n n\u00e0y tr\u00ean m\u1eb7t \u0111\u1ea5t c\u00e0ng cao th\u00ec c\u00e0ng kh\u00f3 \u0111\u1ec3 lo\u1ea1i b\u1ecf t\u00e1c \u0111\u1ed9ng c\u1ee7a ch\u00fang kh\u1ecfi \u1ea3nh.<\/p>\n

D\u1ef1a tr\u00ean \u0111\u1eb7c t\u00ednh, c\u00f3 th\u1ec3 chia k\u00ednh l\u1ecdc ch\u1ed1ng \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng d\u00e0nh cho nhi\u1ebfp \u1ea3nh thi\u00ean v\u0103n DSO ra m\u1ed9t v\u00e0i lo\u1ea1i nh\u01b0 sau:<\/p>\n

\u2013 K\u00ednh l\u1ecdc ph\u1ed5 r\u1ed9ng (Broadband)<\/strong>: K\u00ednh l\u1ecdc ph\u1ed5 r\u1ed9ng ho\u1ea1t \u0111\u1ed9ng c\u00e1ch ch\u1eb7n b\u01b0\u1edbc s\u00f3ng v\u00e0ng cam t\u1eeb \u0111\u00e8n h\u01a1i natri v\u00e0 \u0111\u00e8n h\u01a1i thu\u1ef7 ng\u00e2n, cho ph\u00e9p m\u1ed9t v\u00f9ng ph\u1ed5 ph\u00e1t x\u1ea1 r\u1ea5t r\u1ed9ng truy\u1ec1n qua. V\u00f9ng ph\u1ed5 n\u00e0y bao tr\u00f9m b\u01b0\u1edbc s\u00f3ng ph\u00e1t x\u1ea1 H-beta, O-III (xanh l\u1ee5c) v\u00e0 v\u00f9ng \u0111\u1ecf s\u1eadm ch\u1ee9a H-alpha. Trong \u0111i\u1ec1u ki\u1ec7n \u00e1nh s\u00e1ng th\u00e0nh ph\u1ed1, c\u00e1c lo\u1ea1i k\u00ednh l\u1ecdc ph\u1ed5 r\u1ed9ng y\u1ebfu th\u01b0\u1eddng cho ra \u1ea3nh ng\u1ea3 xanh lam s\u00e1ng. Lo\u1ea1i l\u1ecdc m\u1ea1nh h\u01a1n c\u00f3 th\u1ec3 cho \u1ea3nh sai m\u00e0u nhi\u1ec1u h\u01a1n tu\u1ef3 thu\u1ed9c v\u00e0o v\u00f9ng ph\u1ed5 b\u1ecb c\u1eaft \u0111i. Lo\u1ea1i k\u00ednh l\u1ecdc n\u00e0y th\u01b0\u1eddng t\u1ecf ra k\u00e9m hi\u1ec7u qu\u1ea3 v\u1edbi c\u00e1c ngu\u1ed3n \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng nh\u01b0 \u0111\u00e8n led tr\u1eafng, \u0111\u00e8n hu\u1ef3nh quang (\u0111\u1eb7c bi\u1ec7t lo\u1ea1i n\u00e0o ph\u00e1t ra m\u00e0u xanh d\u01b0\u01a1ng v\u00e0 l\u1ee5c th\u00ec t\u00e1c d\u1ee5ng l\u1ecdc g\u1ea7n nh\u01b0 ko \u0111\u00e1ng k\u1ec3). V\u00ec l\u00fd do n\u00e0y, c\u00e1c lo\u1ea1i k\u00ednh l\u1ecdc ph\u1ed5 r\u1ed9ng th\u01b0\u1eddng ho\u1ea1t \u0111\u1ed9ng t\u1ed1t v\u1edbi b\u1ea7u tr\u1eddi ngo\u1ea1i \u00f4 v\u00e0 v\u00f9ng n\u00f4ng th\u00f4n, n\u01a1i \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng kh\u00f4ng qu\u00e1 n\u1eb7ng n\u1ec1 v\u00e0 ngu\u1ed3n kh\u1edfi ph\u00e1t \u00f4 nhi\u1ec5m kh\u00f4ng qu\u00e1 ph\u1ee9c t\u1ea1p. T\u00e1c d\u1ee5ng ch\u1ee7 y\u1ebfu c\u1ee7a k\u00ednh l\u1ecdc ph\u1ed5 r\u1ed9ng l\u00e0 t\u0103ng c\u01b0\u1eddng \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n c\u1ee7a n\u1ec1n tr\u1eddi, gi\u1ea3m ph\u1ea7n \u00e1nh s\u00e1ng \u00f4 nhi\u1ec5m \u0111\u01b0\u1eddng ch\u00e2n tr\u1eddi, gi\u00fap c\u00e1c tinh v\u00e2n ph\u00e1t x\u1ea1 m\u00e0u \u0111\u1ecf t\u1ed1i v\u00e0 xanh d\u01b0\u01a1ng d\u1ec5 \u201cn\u1ed5i\u201d l\u00ean tr\u00ean n\u1ec1n tr\u1eddi, do \u0111\u00f3 r\u1ea5t ph\u00f9 h\u1ee3p cho ho\u1ea1t \u0111\u1ed9ng quan s\u00e1t v\u00e0 ghi h\u00ecnh b\u1eb1ng DLSR ho\u1eb7c camera color chuy\u00ean d\u1ee5ng.<\/p>\n

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\u1ea2nh tr\u01b0\u1edbc v\u00e0 sau khi s\u1eed d\u1ee5ng k\u00ednh l\u1ecdc Hoya Red intensifier. \u1ea2nh:\u00a0Lonely Speck<\/a>.<\/strong><\/p>\n

\"red_intensifier_filter_review\"
<\/figcaption><\/figure>\n

C\u00e1c lo\u1ea1i k\u00ednh l\u1ecdc ph\u1ed5 r\u1ed9ng kh\u00e1c nhau c\u0169ng cho \u0111\u1eb7c t\u00ednh l\u1ecdc kh\u00e1c nhau. Th\u00f4ng th\u01b0\u1eddng m\u1ed9t s\u1ed1 lo\u1ea1i k\u00ednh l\u1ecdc \u0111\u01b0\u1ee3c \u0111\u1eb7t t\u00ean theo h\u1eadu t\u1ed1\u00a0\u201cNature light\u201d<\/strong><\/em>\u00a0(\u00c1nh s\u00e1ng t\u1ef1 nhi\u00ean) ho\u1eb7c\u00a0\u201cRed intensifier\u201d<\/strong><\/em>\u00a0(T\u0103ng c\u01b0\u1eddng \u0111\u1ecf) ho\u1eb7c\u00a0L-Pro<\/strong><\/em>\u00a0s\u1ebd cho m\u00e0u s\u1eafc t\u1ef1 nhi\u00ean nh\u1ea5t nh\u01b0ng hi\u1ec7u qu\u1ea3 l\u1ecdc kh\u00f4ng \u0111\u01b0\u1ee3c m\u1ea1nh, ph\u00f9 h\u1ee3p cho th\u1ec3 lo\u1ea1i nhi\u1ebfp \u1ea3nh Milkyway v\u00e0 \u1ea3nh thi\u00ean v\u0103n tr\u01b0\u1eddng r\u1ed9ng \u1edf nh\u1eefng n\u01a1i \u00edt \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng. K\u00ednh l\u1ecdc\u00a0CLS (City Light Supression)<\/em><\/strong>\u00a0s\u1ebd cho hi\u1ec7u qu\u1ea3 l\u1ecdc m\u1ea1nh h\u01a1n v\u1edbi sai s\u1ed1 m\u00e0u s\u1eafc l\u00e0 r\u1ea5t \u0111\u00e1ng k\u1ec3, \u1ea3nh s\u1ebd b\u1ecb ng\u1ea3 l\u1ee5c nhi\u1ec1u (nh\u01b0ng c\u00f3 th\u1ec3 s\u1eeda \u0111\u01b0\u1ee3c b\u1eb1ng c\u00e1ch x\u1eed l\u00fd c\u00e2n b\u1eb1ng tr\u1eafng tr\u00ean \u1ea3nh RAW).<\/p>\n

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K\u00ednh l\u1ecdc UHC c\u1ee7a Astronomik ch\u1ec9 cho ph\u00e9p truy\u1ec1n qua v\u00f9ng \u00e1nh s\u00e1ng c\u00f3 d\u1ea3i t\u1eeb 484 \u2013 506nm v\u00e0\u00a0 v\u00f9ng t\u1eeb 630nm tr\u1edf l\u00ean.<\/strong><\/p>\n

\"astronomikuhcfilter\"
<\/figcaption><\/figure>\n

K\u00ednh l\u1ecdc ki\u1ec3u\u00a0UHC (Ultra-High Contrast)<\/strong><\/em>\u00a0s\u1ebd cho hi\u1ec7u qu\u1ea3 l\u1ecdc m\u1ea1nh nh\u1ea5t. Th\u00f4ng th\u01b0\u1eddng, k\u00ednh l\u1ecdc UHC ch\u1ec9 cho ph\u00e9p m\u1ed9t v\u00f9ng r\u1ea5t h\u1eb9p b\u01b0\u1edbc s\u00f3ng \u0111i qua t\u1eeb 484 \u2013 506nm ch\u1ee9a th\u00eam v\u1ea1ch ph\u1ed5 c\u1ee7a H-beta v\u00e0 O-III. Ngo\u00e0i ra, m\u1ed9t s\u1ed1 tinh ch\u1ec9nh th\u00eam c\u00f3 th\u1ec3 cho ph\u00e9p v\u00f9ng \u00e1nh s\u00e1ng \u0111\u1ecf t\u1eeb 630nm tr\u1edf l\u00ean \u0111i qua, v\u00f9ng n\u00e0y ch\u1ee9a v\u1ea1ch ph\u1ed5 H-alpha v\u00e0 S-II. Ngo\u00e0i c\u00e1c v\u00f9ng \u00e1nh s\u00e1ng \u0111\u01b0\u1ee3c ph\u00e9p \u0111i v\u1eeba n\u00eau, ph\u1ea7n c\u00f2n l\u1ea1i s\u1ebd b\u1ecb l\u1ecdc g\u1ea7n nh\u01b0 ho\u00e0n to\u00e0n, hi\u1ec7u qu\u1ea3 c\u00f3 th\u1ec3 \u0111\u1ea1t 90% ho\u1eb7c h\u01a1n.<\/p>\n

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So s\u00e1nh \u1ea3nh tr\u01b0\u1edbc v\u00e0 sau khi s\u1eed d\u1ee5ng k\u00ednh l\u1ecdc Baader UHC-s v\u1edbi th\u1eddi gian ph\u01a1i s\u00e1ng 30 gi\u00e2y (t\u01b0\u01a1ng \u1ee9ng v\u1edbi \u1ea3nh tr\u00e1i v\u00e0 ph\u1ea3i). <\/strong><\/p>\n

H\u00e3y l\u01b0u \u00fd m\u00e0u s\u1eafc c\u00e1c ng\u00f4i sao h\u01a1i ng\u1ea3 l\u1ee5c nh\u1ea1t trong \u1ea3nh b\u00ean ph\u1ea3i. \u1ea2nh:\u00a0Jurgen Kobierczynski<\/a>.<\/strong><\/p>\n

\"6716150985_9ee6559865_b\"
<\/figcaption><\/figure>\n

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K\u00ednh l\u1ecdc UHC th\u01b0\u1eddng cho ra \u1ea3nh c\u00f3 \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n r\u1ea5t cao v\u1edbi n\u1ec1n tr\u1eddi m\u00e0u lam t\u1ed1i ho\u1eb7c c\u00f3 th\u1ec3 h\u01a1i ng\u1ea3 \u0111\u1ecf (ho\u1eb7c h\u1ed3ng t\u00edm). M\u00e0u s\u1eafc c\u00e1c ng\u00f4i sao s\u1ebd b\u1ecb \u1ea3nh h\u01b0\u1edfng n\u1eb7ng v\u00e0 t\u01b0\u01a1ng \u0111\u1ed1i kh\u00f3 \u0111\u1ec3 kh\u00f4i ph\u1ee5c v\u1ec1 nguy\u00ean b\u1ea3n. Do \u0111\u1eb7c t\u00ednh l\u1ecdc qu\u00e1 m\u1ea1nh c\u1ee7a m\u00ecnh, UHC th\u01b0\u1eddng kh\u00f4ng \u0111\u01b0\u1ee3c khuy\u00ean d\u00f9ng \u0111\u1ec3 ch\u1ee5p Milkyway ho\u1eb7c c\u00e1c thi\u00ean h\u00e0 kh\u00e1c (do c\u00e1c v\u1eadt th\u1ec3 n\u00e0y ph\u00e1t ra \u00e1nh s\u00e1ng tr\u1eafng to\u00e0n d\u1ea3i). Ch\u1ee7 y\u1ebfu ng\u01b0\u1eddi ch\u01a1i s\u1ebd d\u00f9ng n\u00f3 v\u00e0o vi\u1ec7c quan s\u00e1t ho\u1eb7c ghi h\u00ecnh tinh v\u00e2n ph\u00e1t x\u1ea1 \u1edf nh\u1eefng n\u01a1i c\u00f3 \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng t\u01b0\u01a1ng \u0111\u1ed1i cao.<\/p>\n

\u2013 K\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p (Narrowband)<\/strong>: K\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p l\u00e0m vi\u1ec7c b\u1eb1ng c\u00e1ch ch\u1eb7n ho\u00e0n to\u00e0n c\u00e1c v\u00f9ng ph\u1ed5 d\u01b0 th\u1eeba, ch\u1ec9 cho truy\u1ec1n qua m\u1ed9t d\u1ea3i r\u1ea5t h\u1eb9p tr\u00ean v\u1ea1ch quang ph\u1ed5 ph\u00e1t x\u1ea1 c\u1ee7a m\u1ed9t ho\u1eb7c v\u00e0i nguy\u00ean t\u1ed1 nh\u1ea5t \u0111\u1ecbnh (th\u01b0\u1eddng l\u00e0 t\u1eeb 22nm tr\u1edf xu\u1ed1ng). Hi\u1ec7u qu\u1ea3 l\u1ecdc c\u1ef1c cao khi\u1ebfn cho lo\u1ea1i k\u00ednh l\u1ecdc n\u00e0y tr\u1edf th\u00e0nh \u1ee9ng c\u1eed vi\u00ean h\u00e0ng \u0111\u1ea7u cho d\u00e2n ch\u01a1i \u1ea3nh thi\u00ean v\u0103n \u1edf nh\u1eefng v\u00f9ng \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng n\u1eb7ng. Th\u1ef1c t\u1ebf, m\u1ed9t v\u00e0i lo\u1ea1i k\u00ednh l\u1ecdc UHC \u0111\u1eb7c bi\u1ec7t c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c ch\u1ebf t\u1ea1o t\u1ed1i \u01b0u t\u1edbi m\u1ee9c cho m\u1ed9t v\u00f9ng ph\u1ed5 \u0111i qua d\u01b0\u1edbi 22nm v\u00e0 nhi\u1ec1u ng\u01b0\u1eddi c\u00f3 th\u1ec3 t\u1ea1m coi \u0111\u00e2y l\u00e0 m\u1ed9t lo\u1ea1i k\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p. Tuy nhi\u00ean, c\u00f3 r\u1ea5t \u00edt lo\u1ea1i k\u00ednh l\u1ecdc UHC nh\u01b0 v\u1eady (v\u00e0 n\u1ebfu c\u00f3, th\u00ec t\u00ean g\u1ecdi c\u1ee7a ch\u00fang c\u0169ng r\u1ea5t kh\u00e1c bi\u1ec7t \u0111\u1ec3 tr\u00e1nh nh\u1ea7m l\u1eabn v\u1edbi c\u00e1c lo\u1ea1i UHC th\u00f4ng d\u1ee5ng v\u00e0 r\u1ebb ti\u1ec1n h\u01a1n) n\u00ean t\u00f4i s\u1ebd t\u1ea1m b\u1ecf qua.<\/p>\n

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M\u1ed9t k\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p Hydrogen Alpha (H-alpha) c\u1ee7a h\u00e3ng Astrodon v\u1edbi d\u1ea3i ph\u1ed5 cho ph\u00e9p truy\u1ec1n qua ch\u1ec9 r\u1ed9ng 5nm.<\/strong><\/p>\n

\"unnamed\"
<\/figcaption><\/figure>\n

Th\u00f4ng th\u01b0\u1eddng, khi nh\u1eafc t\u1edbi k\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p, ch\u00fang ta s\u1ebd ngh\u0129 ngay t\u1edbi lo\u1ea1i k\u00ednh l\u1ecdc ph\u1ed5 ph\u00e1t x\u1ea1 nguy\u00ean t\u1ed1 (Specific emission line). C\u01a1 s\u1edf l\u00fd thuy\u1ebft c\u1ee7a lo\u1ea1i k\u00ednh l\u1ecdc n\u00e0y ch\u1ee7 y\u1ebfu d\u1ef1a v\u00e0o \u0111\u1eb7c t\u00ednh chung c\u1ee7a c\u00e1c tinh v\u00e2n trong v\u0169 tr\u1ee5 th\u01b0\u1eddng ch\u1ee9a m\u1ed9t v\u00e0i nguy\u00ean t\u1ed1 ph\u1ed5 bi\u1ebfn nh\u01b0 hidrogen, helium, nitrogen, sulfur, oxygen\u2026 C\u00e1c nguy\u00ean t\u1ed1 n\u00e0y khi b\u1ecb ion ho\u00e1 s\u1ebd ph\u00e1t ra \u00e1nh s\u00e1ng \u1edf m\u1ed9t b\u01b0\u1edbc s\u00f3ng c\u1ed1 \u0111\u1ecbnh m\u00e0 ch\u00fang ta \u0111\u00e3 bi\u1ebft tr\u01b0\u1edbc. Do \u0111\u00f3, lo\u1ea1i k\u00ednh l\u1ecdc Specific emission line ch\u1ec9 c\u1ea7n cho qua th\u00e0nh ph\u1ea7n \u00e1nh s\u00e1ng n\u00e0y v\u1edbi dung sai th\u1eadt th\u1ea5p v\u00e0 lo\u1ea1i b\u1ecf \u0111i ph\u1ea7n l\u1edbn l\u01b0\u1ee3ng \u00e1nh s\u00e1ng d\u01b0 th\u1eeba. V\u00f9ng \u00e1nh s\u00e1ng \u0111i qua c\u00e0ng h\u1eb9p th\u00ec \u1ea3nh c\u00e0ng c\u00f3 \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n cao v\u00e0 r\u1ea5t \u00edt b\u1ecb d\u00ednh \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng. M\u1ed9t s\u1ed1 lo\u1ea1i k\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p t\u1ed1t nh\u1ea5t hi\u1ec7n nay cho ph\u00e9p m\u1ed9t ph\u1ed5 \u00e1nh s\u00e1ng truy\u1ec1n qua v\u1edbi ph\u1ea1m vi ch\u1ec9 3nm, r\u1ea5t l\u00fd t\u01b0\u1edfng \u0111\u1ec3 ch\u1ee5p trong nh\u1eefng v\u00f9ng \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng n\u1eb7ng v\u00e0 g\u1ea7n nh\u01b0 \u201cmi\u1ec5n nhi\u1ec5m\u201d v\u1edbi \u00e1nh tr\u0103ng v\u00e0 \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng n\u1eb7ng.<\/p>\n

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Tinh v\u00e2n Helix ch\u1ee5p b\u1eb1ng k\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p H-alpha (tr\u00ean) v\u00e0 OIII (d\u01b0\u1edbi) th\u00f4ng qua camera monochrome. <\/strong><\/p>\n

H\u00ecnh \u1ea3nh cho th\u1ea5y s\u1ef1 ph\u00e2n b\u1ed1 c\u1ee7a c\u00e1c nguy\u00ean t\u1ed1 hidrogen v\u00e0 oxygen trong l\u00f2ng tinh v\u00e2n.<\/strong><\/p>\n

\"helix_h_o_narrowband_compare\"
<\/figcaption><\/figure>\n

B\u1ea3n th\u00e2n m\u1ed7i lo\u1ea1i k\u00ednh l\u1ecdc narrowband nh\u1ea5t \u0111\u1ecbnh th\u00ec ch\u1ec9 ph\u1ea3n \u00e1nh \u0111\u01b0\u1ee3c m\u1ed9t m\u00e0u s\u1eafc \u0111\u01a1n nh\u1ea5t c\u1ee7a tinh v\u00e2n. Do \u0111\u00f3, \u0111\u1ec3 th\u1ec3 hi\u1ec7n \u0111\u01b0\u1ee3c m\u00e0u s\u1eafc \u0111\u1ea7y \u0111\u1ee7, ch\u00fang ta c\u1ea7n s\u1eed d\u1ee5ng t\u1ed1i thi\u1ec3u hai ho\u1eb7c ba (ho\u1eb7c nhi\u1ec1u h\u01a1n) c\u00e1c lo\u1ea1i k\u00ednh l\u1ecdc kh\u00e1c nhau. Tuy nhi\u00ean, do \u0111\u00e3 b\u1ecb l\u1ecdc qu\u00e1 nhi\u1ec1u th\u00e0nh ph\u1ea7n n\u00ean m\u00e0u s\u1eafc tr\u00ean \u1ea3nh narrowband kh\u00f4ng ph\u1ea3i l\u00e0 m\u00e0u s\u1eafc th\u1ef1c c\u1ee7a c\u00e1c thi\u00ean th\u1ec3 m\u00e0 m\u1eaft ng\u01b0\u1eddi c\u00f3 th\u1ec3 c\u1ea3m nh\u1eadn \u0111\u01b0\u1ee3c. N\u00ean \u0111\u00f4i nh\u1eefng \u1ea3nh ki\u1ec3u n\u00e0y c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u1ea3nh m\u00e0u gi\u1ea3 \u2013 false color image.<\/p>\n

M\u1ed9t s\u1ed1 lo\u1ea1i k\u00ednh l\u1ecdc m\u1edbi ra m\u1eaft hi\u1ec7n nay nh\u01b0\u00a0Duo-narrowband<\/strong><\/em>,\u00a0Triad-narrowband<\/em><\/strong>\u00a0hay\u00a0L-eNhance<\/strong>\u00a0<\/em>cho ph\u00e9p nhi\u1ec1u h\u01a1n m\u1ed9t v\u00f9ng b\u01b0\u1edbc s\u00f3ng \u0111i qua, nh\u01b0ng \u0111\u1ed9 r\u1ed9ng m\u1ed7i v\u00f9ng m\u00e0 n\u00f3 cho qua v\u1eabn kh\u00f4ng qu\u00e1 22nm n\u00ean v\u1eabn \u0111\u01b0\u1ee3c x\u1ebfp chung v\u00e0o lo\u1ea1i k\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p. Lo\u1ea1i k\u00ednh l\u1ecdc n\u00e0y s\u1ebd cho m\u00e0u s\u1eafc \u0111\u1ea7y \u0111\u1ee7 nh\u01b0ng c\u0169ng ko ph\u1ea3n \u00e1nh m\u00e0u s\u1eafc th\u1ef1c t\u1ebf c\u1ee7a thi\u00ean th\u1ec3.<\/p>\n

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\u1ea2nh tinh v\u00e2n \u0110\u1ea1i B\u00e0ng ch\u1ee5p trong ph\u1ed5 kh\u1ea3 ki\u1ebfn b\u1eb1ng m\u00e1y \u1ea3nh Canon 350D (tr\u00ean) v\u00e0 trong ph\u1ed5 narrowband b\u1eb1ng m\u00e1y thu chuy\u00ean d\u1ee5ng (d\u01b0\u1edbi). <\/i><\/b><\/p>\n

M\u00e0u s\u1eafc trong \u1ea3nh narrowband l\u00e0 m\u00e0u gi\u1ea3 v\u1edbi \u0111\u1ed9 t\u01b0\u01a1ng ph\u1ea3n cao h\u01a1n, c\u00e1c ng\u00f4i sao c\u0169ng nh\u1ecf h\u01a1n.<\/i><\/b><\/p>\n

\"4645311_m16_eagle_nebula_hso_rgb\"
<\/figcaption><\/figure>\n

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H\u00ecnh \u1ea3nh c\u00e1c ng\u00f4i sao khi qua k\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p th\u01b0\u1eddng nh\u1ecf v\u00e0 t\u1ed1i h\u01a1n. K\u00ednh l\u1ecdc d\u1ea3i h\u1eb9p kh\u00f4ng \u0111\u01b0\u1ee3c khuy\u1ebfn ngh\u1ecb s\u1eed d\u1ee5ng \u0111\u1ec3 ch\u1ee5p Ng\u00e2n H\u00e0 hay c\u00e1c thi\u00ean h\u00e0 kh\u00e1c (tr\u1eeb m\u1ed9t s\u1ed1 t\u00ecnh hu\u1ed1ng \u0111\u1eb7c bi\u1ec7t c\u1ea7n k\u1ebft h\u1ee3p d\u1eef li\u1ec7u).<\/p>\n

K\u00ednh l\u1ecdc ch\u1ed1ng \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng tuy c\u00f3 nhi\u1ec1u \u01b0u \u0111i\u1ec3m th\u00fa v\u1ecb nh\u01b0ng bu\u1ed9c ch\u00fang ta c\u0169ng \u0111\u00e1nh \u0111\u1ed5i r\u1ea5t nhi\u1ec1u th\u1ee9, v\u00e0 \u0111a ph\u1ea7n \u0111\u1ec1u t\u00e1c \u0111\u1ed9ng tr\u1ef1c ti\u1ebfp v\u00e0o m\u00e0u s\u1eafc v\u00e0 ch\u1ea5t l\u01b0\u1ee3ng \u1ea3nh thu \u0111\u01b0\u1ee3c. M\u1ed9t gi\u1ea3i ph\u00e1p kh\u00e1c th\u01b0\u1eddng \u0111\u01b0\u1ee3c nhi\u1ec1u ng\u01b0\u1eddi l\u1ef1a ch\u1ecdn, \u0111\u00f3 l\u00e0 di chuy\u1ec3n t\u1edbi nh\u1eefng n\u01a1i c\u00f3 \u00edt \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng \u0111\u1ec3 ch\u1ee5p h\u00ecnh. Th\u1ec3 lo\u1ea1i n\u00e0y \u0111\u01b0\u1ee3c d\u00e2n nghi\u1ec7p d\u01b0 g\u1ecdi chung l\u00e0 travel (ho\u1eb7c mobile) astrophotography.<\/p>\n

Vi\u1ec7c l\u1ef1a ch\u1ecdn thi\u1ebft b\u1ecb cho travel c\u0169ng r\u1ea5t kh\u00e1c so v\u1edbi vi\u1ec7c t\u00ecm mua thi\u1ebft b\u1ecb \u0111\u1ec3 l\u1eafp \u0111\u1eb7t trong m\u1ed9t \u0111\u00e0i thi\u00ean v\u0103n c\u1ed1 \u0111\u1ecbnh. Th\u00f4ng th\u01b0\u1eddng, travel s\u1ebd \u01b0u ti\u00ean nh\u1eefng thi\u1ebft b\u1ecb nh\u1ecf g\u1ecdn, d\u1ec5 tri\u1ec3n khai, y\u00eau c\u1ea7u sai s\u1ed1 kh\u00f4ng qu\u00e1 kh\u1eaft khe. Do \u0111\u00f3 nh\u1eefng \u1ed1ng k\u00ednh tele ti\u00eau c\u1ef1 v\u1eeba ph\u1ea3i ho\u1eb7c k\u00ednh thi\u00ean v\u0103n tr\u01b0\u1eddng r\u1ed9ng s\u1ebd h\u1eefu d\u1ee5ng h\u01a1n so v\u1edbi c\u00e1c d\u00e0n k\u00ednh kh\u1ed5ng l\u1ed3, \u0111\u1eaft \u0111\u1ecf. M\u1ed9t s\u1ed1 tr\u1ee5 b\u00e1m nh\u1eadt \u0111\u1ed9ng g\u1ecdn nh\u1eb9 v\u1edbi thi\u1ebft k\u1ebf center-balanced c\u1ee7a h\u00e3ng iOptron c\u0169ng r\u1ea5t th\u00edch h\u1ee3p cho travel, t\u1ea5t nhi\u00ean n\u1ebfu b\u1ea1n \u0111\u1ee7 cam \u0111\u1ea3m \u0111\u1ec3 th\u1ecfa hi\u1ec7p v\u1edbi v\u00e0i \u201cl\u1ed7i kinh \u0111i\u1ec3n\u201d t\u1edbi t\u1eeb th\u01b0\u01a1ng hi\u1ec7u Trung Qu\u1ed1c n\u00e0y! DSLR \u0111\u00e3 mod k\u00ednh l\u1ecdc h\u1ed3ng ngo\u1ea1i ho\u1eb7c camera l\u00e0m l\u1ea1nh lo\u1ea1i color (OSC) c\u0169ng ti\u1ec7n h\u01a1n so v\u1edbi camera monochrome khi ch\u01a1i \u1ea3nh thi\u00ean v\u0103n travel. Sau \u0111\u00e2y l\u00e0 m\u1ed9t v\u00e0i th\u00f4ng s\u1ed1 thi\u1ebft b\u1ecb g\u1ee3i \u00fd cho ng\u01b0\u1eddi m\u1edbi ch\u01a1i \u1ea3nh thi\u00ean v\u0103n travel theo kinh nghi\u1ec7m c\u1ee7a t\u00f4i:<\/p>\n

 <\/p>\n

\"travel_astro_device_ad\"<\/p>\n","protected":false},"excerpt":{"rendered":"

2. \u00d4 nhi\u1ec5m \u00e1nh s\u00e1ng v\u1edbi nhi\u1ebfp \u1ea3nh thi\u00ean v\u0103n C\u00f3 l\u1ebd kh\u00f4ng c\u1ea7n b\u00e0n nhi\u1ec1u t\u1edbi t\u00e1c h\u1ea1i c\u1ee7a \u00f4 nhi\u1ec5m \u00e1nh s\u00e1ng v\u00e0 \u1ea3nh h\u01b0\u1edfng ti\u00eau c\u1ef1c c\u1ee7a n\u00f3 t\u1edbi nhi\u1ebfp \u1ea3nh thi\u00ean v\u0103n. B\u1ea1n \u0111ang s\u1ed1ng gi\u1eefa trung t\u00e2m th\u00e0nh ph\u1ed1 l\u1edbn nh\u01b0 H\u00e0 N\u1ed9i hay H\u1ed3 Ch\u00ed Minh, b\u1ea1n mu\u1ed1n ch\u1ee5p […]\n","protected":false},"author":1,"featured_media":1351,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[37,1,35],"tags":[47,46],"_links":{"self":[{"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/posts\/1381"}],"collection":[{"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/comments?post=1381"}],"version-history":[{"count":1,"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/posts\/1381\/revisions"}],"predecessor-version":[{"id":1382,"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/posts\/1381\/revisions\/1382"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/media\/1351"}],"wp:attachment":[{"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/media?parent=1381"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/categories?post=1381"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vietweather.com\/index.php\/wp-json\/wp\/v2\/tags?post=1381"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}