{"id":6359,"date":"2025-01-15T20:45:09","date_gmt":"2025-01-16T01:45:09","guid":{"rendered":"https:\/\/www.summet.com\/blog\/?p=6359"},"modified":"2025-01-28T15:22:06","modified_gmt":"2025-01-28T20:22:06","slug":"focal-reducers-f-3-3-and-f-6-6-with-native-meade-f-10-lx200-telescope","status":"publish","type":"post","link":"https:\/\/www.summet.com\/blog\/2025\/01\/15\/focal-reducers-f-3-3-and-f-6-6-with-native-meade-f-10-lx200-telescope\/","title":{"rendered":"Focal Reducers f\/3.3 and f\/6.6 with native Meade f\/10 LX200 telescope"},"content":{"rendered":"<div class='__iawmlf-post-loop-links' style='display:none;' data-iawmlf-post-links='[{&quot;id&quot;:40,&quot;href&quot;:&quot;https:\\\/\\\/en.wikipedia.org\\\/wiki\\\/Bortle_scale&quot;,&quot;archived_href&quot;:&quot;https:\\\/\\\/web-wp.archive.org\\\/web\\\/20260415024543\\\/https:\\\/\\\/en.wikipedia.org\\\/wiki\\\/Bortle_scale&quot;,&quot;redirect_href&quot;:&quot;&quot;,&quot;checks&quot;:[{&quot;date&quot;:&quot;2026-04-15 06:57:48&quot;,&quot;http_code&quot;:200}],&quot;broken&quot;:false,&quot;last_checked&quot;:{&quot;date&quot;:&quot;2026-04-15 06:57:48&quot;,&quot;http_code&quot;:200},&quot;process&quot;:&quot;done&quot;}]'><\/div><p>I have a Meade LX200GPS &#8211; 12&#8243; SCT telescope, which has a focal length of 3048mm (305mm aperture) and a focal ration of f\/10.\u00a0 This telescope is great for planetary imaging (what I&#8217;m mostly limited to, living in a <a href=\"https:\/\/en.wikipedia.org\/wiki\/Bortle_scale\">Bortle 7-8 light <\/a>pollution area, but there exist optical accessories called Focal Reducers which allow you to get this telescope down to a quick f\/6.3 or an incredibly fast f\/3.3. <br \/><br \/><br \/><\/p>\r\n<p>I&#8217;ve purchased both an Anteries f\/6.3 and a Meade series 4000 CCD f\/3.3 focal reducer for my telescope, and have been playing around with them and my Sony A6300 crop sensor camera.<\/p>\r\n<div id=\"attachment_6362\" style=\"width: 594px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/f3.3-ccd-fr-meade-lx200-12inch-sony-a6300-M42-16x9-1-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6362\" class=\"size-large wp-image-6362\" src=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/f3.3-ccd-fr-meade-lx200-12inch-sony-a6300-M42-16x9-1-1024x576.jpg\" alt=\"\" width=\"584\" height=\"329\" srcset=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/f3.3-ccd-fr-meade-lx200-12inch-sony-a6300-M42-16x9-1-1024x576.jpg 1024w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/f3.3-ccd-fr-meade-lx200-12inch-sony-a6300-M42-16x9-1-300x169.jpg 300w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/f3.3-ccd-fr-meade-lx200-12inch-sony-a6300-M42-16x9-1-768x432.jpg 768w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/f3.3-ccd-fr-meade-lx200-12inch-sony-a6300-M42-16x9-1-1536x864.jpg 1536w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/f3.3-ccd-fr-meade-lx200-12inch-sony-a6300-M42-16x9-1-2048x1152.jpg 2048w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/f3.3-ccd-fr-meade-lx200-12inch-sony-a6300-M42-16x9-1-500x281.jpg 500w\" sizes=\"auto, (max-width: 584px) 100vw, 584px\" \/><\/a><p id=\"caption-attachment-6362\" class=\"wp-caption-text\">f\/3.3 Meade Series 4000 Focal Reducer, 10 second exposure, ISO 400<\/p><\/div>\r\n<div id=\"attachment_6363\" style=\"width: 594px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-F63FR-A6300-20sec-OrionNebula-16x9-1-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6363\" class=\"size-large wp-image-6363\" src=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-F63FR-A6300-20sec-OrionNebula-16x9-1-1024x576.jpg\" alt=\"\" width=\"584\" height=\"329\" srcset=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-F63FR-A6300-20sec-OrionNebula-16x9-1-1024x576.jpg 1024w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-F63FR-A6300-20sec-OrionNebula-16x9-1-300x169.jpg 300w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-F63FR-A6300-20sec-OrionNebula-16x9-1-768x432.jpg 768w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-F63FR-A6300-20sec-OrionNebula-16x9-1-1536x864.jpg 1536w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-F63FR-A6300-20sec-OrionNebula-16x9-1-2048x1152.jpg 2048w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-F63FR-A6300-20sec-OrionNebula-16x9-1-500x281.jpg 500w\" sizes=\"auto, (max-width: 584px) 100vw, 584px\" \/><\/a><p id=\"caption-attachment-6363\" class=\"wp-caption-text\">Antares f\/6.3 focal reducer, 20 second exposure (unknown ISO, possibly 400)<\/p><\/div>\r\n<p>&nbsp;<\/p>\r\n<div id=\"attachment_6364\" style=\"width: 594px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-A6300-20sec-orion-nebula-native-f-10-16x9-1-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6364\" class=\"size-large wp-image-6364\" src=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-A6300-20sec-orion-nebula-native-f-10-16x9-1-1024x576.jpg\" alt=\"\" width=\"584\" height=\"329\" srcset=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-A6300-20sec-orion-nebula-native-f-10-16x9-1-1024x576.jpg 1024w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-A6300-20sec-orion-nebula-native-f-10-16x9-1-300x169.jpg 300w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-A6300-20sec-orion-nebula-native-f-10-16x9-1-768x432.jpg 768w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-A6300-20sec-orion-nebula-native-f-10-16x9-1-1536x864.jpg 1536w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-A6300-20sec-orion-nebula-native-f-10-16x9-1-2048x1152.jpg 2048w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/LX200-A6300-20sec-orion-nebula-native-f-10-16x9-1-500x281.jpg 500w\" sizes=\"auto, (max-width: 584px) 100vw, 584px\" \/><\/a><p id=\"caption-attachment-6364\" class=\"wp-caption-text\">Native LX200GPS &#8211; 12 inch f\/10, 20 second exposure<\/p><\/div>\r\n<p><!--more--><\/p>\r\n<p>The f\/3.3 focal reducer is designed to be used with a small CCD imaging sensor (sold many years ago) and has a lot of vignetting and drop off near the edge of my crop sensor when used with only 50mm of backfocus (so little that I couldn&#8217;t include my electronic focuser in the optical path). Some of this could be resolved by calibrating the optical path with light frames, but I feel that the f\/3.3 reducer is better for a smaller image sensor region in the center, so you don&#8217;t really get the full advantage of the 0.839 degree FOV.<\/p>\r\n<p>I was able to move the camera very close to the f\/3.3 focal reducer by using a NEX-&gt;M48 T-ring and a M48-&gt;SCT thread adapter. [Probably around 10-15mm of backfocus behind the lens of the focal reducer, no room for the electronic focuser or even a filter.\u00a0 This gave me a more usable view (only the very corners had vignetting\/dropoff) but a smaller FOV ( 0.487 degree, close to that achieved with the f\/6.6 focal reducer.) I actually didn&#8217;t miss the electronic focuser as at f\/3.3 the standard focus knob on my LX200 worked just fine with a bahtinav mask and I could achieve fine focus with it. <br \/><br \/>The f\/6.6 focal reducer worked well with the crop sensor size and almost the entire 0.436 degree FOV was usable, even with the camera attached to the end of the electronic focuser (~ 50 mm of backfocus).<\/p>\r\n<p>The native f\/10 native focal ratio gives a relatively small 0.245 degree FOV, and a lot less light so you need higher ISO\/Gain settings or longer exposure times, and is really better for planetary imaging than deep space objects astrophotography.<\/p>\r\n<p>&nbsp;<\/p>\r\n\r\n<p>A video about the f\/6.3 focal reducer:<\/p>\r\n<p><br \/><iframe loading=\"lazy\" title=\"YouTube video player\" src=\"https:\/\/www.youtube-nocookie.com\/embed\/0-3pPBIzVB4?si=IQe7roMOUWoxK5o5\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><br \/><br \/>A video about the f\/3.3 focal reducer:<\/p>\r\n<p><iframe loading=\"lazy\" title=\"YouTube video player\" src=\"https:\/\/www.youtube-nocookie.com\/embed\/d__UVtsR2_g?si=8JvbLNGXbkcKL86M\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\r\n<p>&nbsp;<\/p>\r\n<p>I took a hundred 10 second exposures with the f\/3.3 FR of M42 the great Orion nebula and stacked them with SIRIL for this result:<\/p>\r\n<div id=\"attachment_6370\" style=\"width: 594px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/m42-orion-LX200-12inch-f3.3-A6300-siril_stacked-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6370\" class=\"size-large wp-image-6370\" src=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/m42-orion-LX200-12inch-f3.3-A6300-siril_stacked-1024x771.jpg\" alt=\"Astrophotography of M42 (Great Orion nebula) showing red and blue dust clouds in front of stars\" width=\"584\" height=\"440\" srcset=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/m42-orion-LX200-12inch-f3.3-A6300-siril_stacked-1024x771.jpg 1024w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/m42-orion-LX200-12inch-f3.3-A6300-siril_stacked-300x226.jpg 300w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/m42-orion-LX200-12inch-f3.3-A6300-siril_stacked-768x578.jpg 768w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/m42-orion-LX200-12inch-f3.3-A6300-siril_stacked-1536x1157.jpg 1536w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/m42-orion-LX200-12inch-f3.3-A6300-siril_stacked-2048x1542.jpg 2048w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/m42-orion-LX200-12inch-f3.3-A6300-siril_stacked-398x300.jpg 398w\" sizes=\"auto, (max-width: 584px) 100vw, 584px\" \/><\/a><p id=\"caption-attachment-6370\" class=\"wp-caption-text\">Click for full size<\/p><\/div>\r\n<p>&nbsp;<\/p>\r\n<p>I did the same thing with the f\/6.3 FR, which allowed me to also use a SVBony SV220 dual narrow band filter to get this result:<\/p>\r\n<div id=\"attachment_6371\" style=\"width: 594px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/M42-Orion-LX200-f6.3-A6300-sv220-siril-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-6371\" class=\"size-large wp-image-6371\" src=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/M42-Orion-LX200-f6.3-A6300-sv220-siril-1024x685.jpg\" alt=\"Astrophotography of M42, the Great Orion Nebula, showing dust clouds with red and white light\" width=\"584\" height=\"391\" srcset=\"https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/M42-Orion-LX200-f6.3-A6300-sv220-siril-1024x685.jpg 1024w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/M42-Orion-LX200-f6.3-A6300-sv220-siril-300x201.jpg 300w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/M42-Orion-LX200-f6.3-A6300-sv220-siril-768x514.jpg 768w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/M42-Orion-LX200-f6.3-A6300-sv220-siril-1536x1027.jpg 1536w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/M42-Orion-LX200-f6.3-A6300-sv220-siril-2048x1369.jpg 2048w, https:\/\/www.summet.com\/blog\/wp-content\/uploads\/2025\/01\/M42-Orion-LX200-f6.3-A6300-sv220-siril-449x300.jpg 449w\" sizes=\"auto, (max-width: 584px) 100vw, 584px\" \/><\/a><p id=\"caption-attachment-6371\" class=\"wp-caption-text\">Click for full size<\/p><\/div>","protected":false},"excerpt":{"rendered":"<p>I have a Meade LX200GPS &#8211; 12&#8243; SCT telescope, which has a focal length of 3048mm (305mm aperture) and a focal ration of f\/10.\u00a0 This telescope is great for planetary imaging (what I&#8217;m mostly limited to, living in a Bortle &hellip; <a href=\"https:\/\/www.summet.com\/blog\/2025\/01\/15\/focal-reducers-f-3-3-and-f-6-6-with-native-meade-f-10-lx200-telescope\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,2],"tags":[155],"class_list":["post-6359","post","type-post","status-publish","format-standard","hentry","category-reviews","category-technology","tag-lx200"],"_links":{"self":[{"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/posts\/6359","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/comments?post=6359"}],"version-history":[{"count":6,"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/posts\/6359\/revisions"}],"predecessor-version":[{"id":6372,"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/posts\/6359\/revisions\/6372"}],"wp:attachment":[{"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/media?parent=6359"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/categories?post=6359"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.summet.com\/blog\/wp-json\/wp\/v2\/tags?post=6359"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}