{"id":1212,"date":"2023-11-02T17:55:43","date_gmt":"2023-11-02T16:55:43","guid":{"rendered":"http:\/\/astroriom.net\/v2\/?p=1212"},"modified":"2023-11-02T17:55:43","modified_gmt":"2023-11-02T16:55:43","slug":"choisir-ses-oculaires","status":"publish","type":"post","link":"https:\/\/astroriom.net\/v2\/?p=1212","title":{"rendered":"Choisir ses oculaires"},"content":{"rendered":"\n<p><strong>CHOISIR SON OCULAIRE<\/strong><\/p>\n\n\n\n<p><strong>&#8211; &#8211; &#8211; &#8211; &#8211; &#8211; &#8211;<\/strong><\/p>\n\n\n\n<p><em>l\u2019oculaire est une sorte de loupe tr\u00e8s perfectionn\u00e9e qui grossit l\u2019image afin que cette derni\u00e8re puisse fournir des d\u00e9tails plus ou moins visibles de l\u2019objet observ\u00e9.<\/em><\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"512\" height=\"330\" src=\"http:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_diversite.png\" alt=\"\" class=\"wp-image-1213\" srcset=\"https:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_diversite.png 512w, https:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_diversite-300x193.png 300w\" sizes=\"auto, (max-width: 512px) 100vw, 512px\" \/><\/figure>\n\n\n\n<p>Ce qui compte dans le choix d\u2019un oculaire :<strong><\/strong><\/p>\n\n\n\n<p><strong>La focale <\/strong>(nombre indiqu\u00e9 en millim\u00e8tre sur chaque oculaire)<\/p>\n\n\n\n<p><strong>Le champ apparent <\/strong>exprim\u00e9 en degr\u00e9s<\/p>\n\n\n\n<p><strong>Le prix : <\/strong>les oculaires \u00e0 moins de 90 \u20ac sont g\u00e9n\u00e9ralement bas de gamme<\/p>\n\n\n\n<p><strong>Ce que l\u2019on souhaite observer : <\/strong>plan\u00e8tes ou ciel profond<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>2 coulants standards: 1,25 et 2 pouces (31,75 et 50,8mm)<\/li>\n\n\n\n<li>Diff\u00e9rentes <strong>formules optiques <\/strong>(plusieurs lentilles &#8211; limite les aberrations)<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"450\" height=\"600\" src=\"http:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_technologie.png\" alt=\"\" class=\"wp-image-1214\" srcset=\"https:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_technologie.png 450w, https:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_technologie-225x300.png 225w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><\/figure>\n\n\n\n<p>Oculaires de type Huygens, Ramsden, Kellner, RKE (Edmund Scientific) , Orthoscopique (Zeiss; Baader), Pl\u00f6ssl et Erfle<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"119\" src=\"http:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_huygens.png\" alt=\"\" class=\"wp-image-1215\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"119\" src=\"http:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_kellner.png\" alt=\"\" class=\"wp-image-1216\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"119\" src=\"http:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_monocentric.png\" alt=\"\" class=\"wp-image-1217\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"119\" src=\"http:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_plossl.png\" alt=\"\" class=\"wp-image-1218\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"119\" src=\"http:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_orthoscopic.png\" alt=\"\" class=\"wp-image-1219\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"119\" src=\"http:\/\/astroriom.net\/v2\/wp-content\/uploads\/2023\/11\/occulaires_erfle.png\" alt=\"\" class=\"wp-image-1220\"\/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>la distance focale (ou focale f): de 4 \u00e0 40mm!<\/li>\n<\/ul>\n\n\n\n<p>Distance entre le foyer image (point de convergence) et le centre optique de la lentille<\/p>\n\n\n\n<p><strong>Le choix de la focale de l&rsquo;oculaire conditionne le grossissement de l&rsquo;objet vis\u00e9<\/strong><\/p>\n\n\n\n<p><strong>G = Focale de l&rsquo;instrument\/focale de l&rsquo;oculaire<\/strong><\/p>\n\n\n\n<p><em>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Focale courte: grossissement \u00e9lev\u00e9 &#8212;&#8212;&gt; PLANETES<\/em><\/p>\n\n\n\n<p><em>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Focale longue: faible grossissement &#8212;&#8212;&#8211;&gt; CP (galaxies, n\u00e9buleuses&#8230;)<\/em><\/p>\n\n\n\n<p><strong>Le grossissement maximum utilisable d\u00e9pend avant tout des conditions du ciel!<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>le champ apparent (en degr\u00e9s): de 30 \u00e0 100\u00b0<\/li>\n<\/ul>\n\n\n\n<p>Secteur de visibilit\u00e9 permis par la formule optique retenue et la focale de l&rsquo;oculaire<\/p>\n\n\n\n<p><strong>D\u00e9tails plan\u00e8tes: <em>petit champ<\/em>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <\/strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <strong>Objets CP: <em>grand champ<\/em><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Choisir une gamme optimale: rapport focal et pupille de sortie<em><\/em><\/li>\n<\/ul>\n\n\n\n<p>&#8211; D\u00e9terminer le <strong>rapport focal <\/strong>de l&rsquo;instrument (ex: F\/D = 7)<\/p>\n\n\n\n<p>&#8211; Multiplier F\/D par <strong>pupille de sortie <\/strong>oculaire (PSmax: 7mm; <strong>choisir 5mm<\/strong>)<\/p>\n\n\n\n<p>&#8211; Lune, plan\u00e8tes, n\u00e9buleuses \u00e9troites: PS=2mm&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 7 x 2 = 14mm (champ moyen)<\/p>\n\n\n\n<p>&#8211; n\u00e9buleuses \u00e9tendues, galaxies: PS=3mm&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 7 x 3 = 21mm (grand champ)<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>D\u00e9fauts de l&rsquo;oeil; port de lunettes et <strong>relief d&rsquo;oeil<\/strong><\/li>\n<\/ul>\n\n\n\n<p>astigmatisme &#8212;-&gt; s\u00e9lectionner un oculaire avec un bon d\u00e9gagement (20mm)<\/p>\n\n\n\n<p>myopie, presbytie, hyperm\u00e9tropie: r\u00e9gler la mise au point sur l&rsquo;instrument<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Le prix: de 30 \u00e0 1200 \u20ac!<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>CHOISIR SON OCULAIRE &#8211; &#8211; &#8211; &#8211; &#8211; &#8211; &#8211; l\u2019oculaire est une sorte de loupe tr\u00e8s perfectionn\u00e9e qui grossit l\u2019image afin que cette derni\u00e8re puisse fournir des d\u00e9tails plus ou moins visibles de l\u2019objet observ\u00e9. Ce qui compte dans le choix d\u2019un oculaire : La focale (nombre indiqu\u00e9 en millim\u00e8tre sur chaque oculaire) Le &hellip; <a href=\"https:\/\/astroriom.net\/v2\/?p=1212\" class=\"more-link\">Lire la suite de <span class=\"screen-reader-text\">Choisir ses oculaires<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[],"class_list":["post-1212","post","type-post","status-publish","format-standard","hentry","category-premierspas","no-featured-image"],"_links":{"self":[{"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=\/wp\/v2\/posts\/1212","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1212"}],"version-history":[{"count":1,"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=\/wp\/v2\/posts\/1212\/revisions"}],"predecessor-version":[{"id":1221,"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=\/wp\/v2\/posts\/1212\/revisions\/1221"}],"wp:attachment":[{"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1212"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1212"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/astroriom.net\/v2\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1212"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}