{"id":1104,"date":"2019-06-15T15:18:21","date_gmt":"2019-06-15T13:18:21","guid":{"rendered":"https:\/\/koustrup.com\/?page_id=1104"},"modified":"2022-10-15T15:07:42","modified_gmt":"2022-10-15T13:07:42","slug":"neutral-graafilter-nd-filter","status":"publish","type":"page","link":"https:\/\/foto-video.dk\/?page_id=1104","title":{"rendered":"10.4: Neutral- \/ gr\u00e5filter (ND filter)"},"content":{"rendered":"<nav aria-label=\"breadcrumbs\">\n            <div class=\"breadcrumb-container theme1\">\n                <ol>\n                    <li><a title=\"Du er her\" href=\"#\"><span>Du er her<\/span><\/a><span class=\"separator\">&gt;&gt;<\/span><\/li>\n                    <\/ol>\n            <\/div>\n        <\/nav>    <script type=\"application\/ld+json\">\n        {\n            \"@context\": \"http:\/\/schema.org\",\n            \"@type\": \"BreadcrumbList\",\n            \"itemListElement\": [\n                 {\n                            \"@type\": \"ListItem\",\n                            \"position\": 1,\n                            \"item\": {\n                                \"@id\": \"#\",\n                                \"name\": \"Du er her\"\n                            }\n                        }\n                                                    ]\n        }\n    <\/script>\n   \n    <script>\n            <\/script>\n\n<hr \/>\n<p>Filtrets prim\u00e6re funktion er at d\u00e6mpe lyset (mindre lys til sensoren) uden at p\u00e5virke farver og skarphed. Lysd\u00e6mpningen skal for filtret v\u00e6re ens over hele filtret (undtaget graduerede filtre).<\/p>\n<p>Filterene kan f\u00e5s med en fast lysd\u00e6mpnings-faktor, fx ND2 eller som variabel d\u00e6mpning, fx ND2 til ND400.<\/p>\n<p>Det bruges is\u00e6r til at for\u00f8ge lukkertiden, s\u00e5 man kan bruge et lavere F-nummer end ellers. Lange lukkertider kan ogs\u00e5 \u2018fjerne\u2019 u\u00f8nskede bev\u00e6gelige elementer, fx turister eller biler.<\/p>\n<hr \/>\n<p>For hvert stop halveres lyset.\u00a0Dvs. at et ND 4 filter vil neds\u00e6tte lysm\u00e6ngden med to stop \u2013 eller 1\/(2*2)<\/p>\n<p><!-- Tabel inden i tabellen --><\/p>\n<table style=\"width: 80%; float: center; border: 2px solid black; padding: 3px; margin-right: auto; margin-left: auto;\">\n<tbody>\n<tr>\n<th style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">Filter nr.<\/th>\n<th style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">F-stops<\/th>\n<th style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">lysreduktion<\/th>\n<th style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">Densitet<\/th>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND2<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/2<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">0,3 ND<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND4<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">2<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/4<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">0,6 ND<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND8<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">3<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/8<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">0,9 ND<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND16<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">4<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/16<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1,2 ND<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND32<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">5<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/32<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1,5 ND<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND400<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">8 2\/3<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/408<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">2,6 ND<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND1000<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">10<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/1024<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">3,0 ND<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Generelt:\u00a0<strong>Lysreduktion = 1 \/ (2 ^ F-stops)<\/strong><\/p>\n<p>Husk mht. EV: 1 F-stop ned (fx 11 -&gt; 16), vil medf\u00f8re at lukkertiden skal fordobles.<\/p>\n<hr \/>\n<p>P\u00e5 en meget solrig sommerdag \u00f8nskede jeg, at fotografere b\u00f8lgerne der slog mod kysten. Men jeg \u00f8nskede, at b\u00f8lgetoppene fik et &#8216;bl\u00f8dt&#8217; udseende. Samtidigt \u00f8nskede jeg, at undg\u00e5 at komme over <em><strong>f<\/strong><\/em>16 p\u00e5 bl\u00e6nden for at undg\u00e5 lysdiffraktion.<\/p>\n<p>De bl\u00f8de b\u00f8lgetoppe kunne jeg f\u00e5 ved ca. 1\/4 sekund i lukker hastighed. S\u00e5 jeg indstillede kameraet til laveste ISO (200), lukkerhastighed p\u00e5 1\/4 sekund og bl\u00e6nden p\u00e5<em><strong> f<\/strong><\/em>16 og fik f\u00f8lgende billede &#8211;<\/p>\n<p><a href=\"https:\/\/koustrup.com\/wp-content\/uploads\/2019\/06\/filter11.jpg\"><img decoding=\"async\" class=\"aligncenter size-large wp-image-1186\" src=\"https:\/\/koustrup.com\/wp-content\/uploads\/2019\/06\/filter11-1024x680.jpg\" alt=\"\" width=\"1024\" height=\"680\" \/><\/a><\/p>\n<p>Billedet er (som forventet) helt klart overeksponeret. Jeg monterede derfor et ND16 filter p\u00e5 objektivet, og tog derefter f\u00f8lgende billede &#8211;<\/p>\n<p><a href=\"https:\/\/koustrup.com\/wp-content\/uploads\/2019\/06\/filter12.png\"><img decoding=\"async\" class=\"aligncenter size-large wp-image-1188\" src=\"https:\/\/koustrup.com\/wp-content\/uploads\/2019\/06\/filter12-1024x680.png\" alt=\"\" width=\"1024\" height=\"680\" \/><\/a><\/p>\n<p>Hvilket blev korrekt eksponeret.<\/p>\n<hr \/>\n<p>Generelt kan man beregne hvilket filter man skal bruge &#8211; og hvilke stop vi g\u00e5r ned n\u00e5r vi bruger filtret efter f\u00f8lgende (eksempel) &#8211;<\/p>\n<p>Hvis lysm\u00e5leren viser vi skal bruge F11 ved 1\/250 sekund og ISO 200, for at f\u00e5 korrekt eksponering (EV=15), vil vi skulle forl\u00e6nge lukkertiden som nedenst\u00e5ende (F-v\u00e6rdi konstant, ISO 200) &#8211;<\/p>\n<p><!-- Tabel inden i tabellen --><\/p>\n<table style=\"width: 90%; float: center; border: 2px solid black; padding: 3px; margin-right: auto; margin-left: auto;\">\n<tbody>\n<tr>\n<th style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">Filter nr.<\/th>\n<th style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">F-stops<\/th>\n<th style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">lysreduktion<\/th>\n<th style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">Lukkerhastighed<\/th>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\"><\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">0<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/250 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND2<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/2<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/125 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND4<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">2<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/4<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/60 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND8<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">3<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/8<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/30 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND16<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">4<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/16<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/15 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND32<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">5<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/32<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/8 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND64<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">6<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/64<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/4 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND128<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">7<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/128<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/2 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND256<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">8<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/256<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND400<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">8 2\/3<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/408<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1,6 s<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">ND1000<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">10<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">1\/1024<\/td>\n<td style=\"text-align: center; vertical-align: middle; width: 25%; border: 1px solid black; padding: 2px;\">4,1 s<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Formel: T(nd)\u00a0= T(0) x (2^ND)<\/strong><\/p>\n<p>Hvor:<br \/>\nT(nd) = lukkerhastighed med ND-filter<br \/>\nT(0) =lukkerhastighed uden filter<br \/>\nND = F-stop v\u00e6rdi af ND-filter<\/p>\n<hr \/>\n<p>Man skal ogs\u00e5 huske p\u00e5, at filteret kan neds\u00e6tte lyset s\u00e5 meget, at autofokus ikke fungerer. Man kan derfor blive n\u00f8dt til at fokusere manuelt eller autofokusere uden filter og derfor montere filteret og sl\u00e5 autofokus fra.<\/p>\n<hr \/>\n<p>Det g\u00e6lder for ND filtre som med alle andre filtre, de skal v\u00e6re af en god kvalitet. Mange af de lidt billigere filtre har en tendens til at misfarve billedet, fx i retning af cyan eller magenta. Det kan klares ved at arbejde p\u00e5 hvidbalancen, men resultatet bliver sj\u00e6ldent supergodt.<\/p>\n<p>Det bedste er, at g\u00e5 ned til den lokale fotohandler og bede om at afpr\u00f8ve filtrene INDEN du k\u00f8ber dem. Alternativt f\u00e5 en aftale om at kunne sende dem tilbage, hvis du ikke er tilfreds med resultatet.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Filtrets prim\u00e6re funktion er at d\u00e6mpe lyset (mindre lys til sensoren) uden at p\u00e5virke farver og skarphed. Lysd\u00e6mpningen skal for filtret v\u00e6re ens over hele filtret (undtaget graduerede filtre). Filterene kan f\u00e5s med en fast lysd\u00e6mpnings-faktor, fx ND2 eller som variabel d\u00e6mpning, fx ND2 til ND400. Det bruges is\u00e6r til at for\u00f8ge lukkertiden, s\u00e5 man [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":1086,"menu_order":40,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1104","page","type-page","status-publish","hentry","post"],"_links":{"self":[{"href":"https:\/\/foto-video.dk\/index.php?rest_route=\/wp\/v2\/pages\/1104","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/foto-video.dk\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/foto-video.dk\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/foto-video.dk\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/foto-video.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1104"}],"version-history":[{"count":9,"href":"https:\/\/foto-video.dk\/index.php?rest_route=\/wp\/v2\/pages\/1104\/revisions"}],"predecessor-version":[{"id":3134,"href":"https:\/\/foto-video.dk\/index.php?rest_route=\/wp\/v2\/pages\/1104\/revisions\/3134"}],"up":[{"embeddable":true,"href":"https:\/\/foto-video.dk\/index.php?rest_route=\/wp\/v2\/pages\/1086"}],"wp:attachment":[{"href":"https:\/\/foto-video.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}