{"id":9713,"date":"2015-05-03T20:12:57","date_gmt":"2015-05-03T20:12:57","guid":{"rendered":"https:\/\/groupeastronomiespa.be\/astrogas\/solar-imaging-increasing-f-d-ii-telecentric-double-stack\/"},"modified":"2025-06-08T22:46:04","modified_gmt":"2025-06-08T20:46:04","slug":"solar-imaging-increasing-f-d-ii-telecentric-double-stack","status":"publish","type":"post","link":"https:\/\/groupeastronomiespa.be\/astrogas\/solar-imaging-increasing-f-d-ii-telecentric-double-stack\/","title":{"rendered":"Solar imaging – Increasing F\/D (II) – Telecentric Double Stack"},"content":{"rendered":"

English test later in italic<\/p>\n

L’essai pr\u00e9c\u00e9dent d’augmentation du rapport FD au niveau de l’\u00e9talon ne m’avait pas donn\u00e9 satisfaction.
\nVoici une nouvelle tentative en empilant … deux t\u00e9l\u00e9centriques: X4 et X2
\nLe but d’une t\u00e9l\u00e9centrique en Ha est d’arriver \u00e0 des rayons parall\u00e8les au niveau de l’\u00e9talon.
\nVoulant augmenter le rapport F\/D au niveau de l’\u00e9talon, je suppose qu’une deuxi\u00e8me t\u00e9l\u00e9centrique ne devrait pas faire de mal \u00e0 ce niveau.
\nLe montage est quand sujet \u00e0 questions. Dans un sch\u00e9ma avec une t\u00e9l\u00e9centrique, la CCD a une position optimale. Dans le cas d’un double t\u00e9l\u00e9centrique, o\u00f9 positionner la deuxi\u00e8me?
\nJe m’attendais \u00e0 une surprise quant \u00e0 la qualit\u00e9 du r\u00e9sultat. Ce qui est le plus \u00e9tonnant, c’est de voir une partie du champ hors du domaine Ha.<\/p>\n

Le tirage du r\u00e9ducteur de focale est adapt\u00e9 de mani\u00e8re \u00e0 avoir un champ \u00e9quivalent.
\nA gauche, x4
\nA droite, x4 +x2 + augmentation tirage
\n———————————————————————————————————————————–
\nThe previous trial of increasing the F\/D ration at the etalon had not given me satisfaction.
\nHere is another attempt by stacking two … telecentrics: X4 and X2
\nThe purpose of a telecentric in Ha is to achieve parallel rays at the etalon.
\nWanting to increase the F\/D ration at the level of the etalon, I suppose a second telecentric should not hurt at this level.
\nSuch system is subject to questions. In a setup with one telecentric, the CCD has an optimum position. In the case of a double telecentric, wherein positioning the second?
\nI expected a surprise with the quality of the result. What is most amazing is to see a portion of the field outside Ha range.<\/em><\/p>\n

The distance between the focal reducer and the CCD is adjusted to have an equivalent field in both cases.
\nLeft, x4
\nRight, x4 +x2 + focal reducer repositioning.
\n———————————————————————————————————————————–<\/p>\n

Captures primaires, alignement et empilage:
\nPrimary captures, alignment and stacking:<\/em>
\n\"\"<\/a><\/p>\n

Coupure du niveau bas sous PS pour \u00e9liminer les parties basses non remplies par l’histogramme:
\nCropping the low level in PS, in order to remove the unfilled part the histogram:<\/em>
\n\"\"<\/a><\/p>\n

———————————————————————————————————————————–
\nAlexandre
\n2015-Apr-10
\nFrance-South
\nERF
\nTaka FS128 f8
\nBaader TZ4 (+ TZ2 optipnal)
\nSolar Spectrum 0.3A
\nFocal reducer
\nExtension (Optional)
\nBasler ACA1300<\/p>\n\n\n

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\n Veuillez voter<\/span>\n <\/div>\n <\/div>\n","protected":false},"excerpt":{"rendered":"

English test later in italic L’essai pr\u00e9c\u00e9dent d’augmentation du rapport FD au niveau de l’\u00e9talon ne m’avait pas donn\u00e9 satisfaction. Voici une nouvelle tentative en empilant … deux t\u00e9l\u00e9centriques: X4 et X2 Le but d’une t\u00e9l\u00e9centrique en Ha est d’arriver \u00e0 des rayons parall\u00e8les au niveau de l’\u00e9talon. Voulant augmenter le rapport F\/D au niveau […]<\/p>\n","protected":false},"author":16,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[3],"tags":[],"class_list":["post-9713","post","type-post","status-publish","format-standard","hentry","category-astrobricolage"],"_links":{"self":[{"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/posts\/9713","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/comments?post=9713"}],"version-history":[{"count":1,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/posts\/9713\/revisions"}],"predecessor-version":[{"id":11973,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/posts\/9713\/revisions\/11973"}],"wp:attachment":[{"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/media?parent=9713"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/categories?post=9713"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/tags?post=9713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}