Dear sky lovers,
For serious amateur astronomers it is likely that they tend to buy astronomical telescope at premium level. That is, they are likely to spend tens of thousands of dollars to purchase only the best, most likely a triplet apochromate carries the brand name “Astrophysics” , “TMB” or “Takahashi”..…….
For a beginner or an average amateur they walk entirely a different approach. They could spend only modest amount and, sadly, the majority of instrument sold at this level, to put them dedicatedly……. trashscope – they either exhibit unforgettable chromatic aberration or marked spherical aberration or a combination of both. Rather than nurturing a lifelong interest in astronomy, these scopes frustrate their users and end up in either under the bed or inside some store room, never to see starlight again.
However this doesn’t mean that you cannot find a quality starter scope at an entry level price. The China brand “Maxivision” has just announced a series of Triplet APO from their manufacturing line which starts at a surprisingly affordable price. Their 80 mm f/6, equipped with an APO triplet objective lens, priced astonishingly just below HK$ 3000.
To test the optical ability of this telescope we set up a Maxivison against a William Optic 80 mm APO and targeted at Jupiter for a AB comparison. ( at 110X ) The William Optics, priced at more than double of the Maxivision, showed, as expected, a crisp, sharp Jupiter with very high contrast. We switched at once to the Maxivison, at the same power to view at Jupiter again.
The chromatic aberration of the Maxivision was so small that it is practically undetected by naked eye. Judging from the energy inside and outside focal plane it was discovered that small amount of spherical aberration was still left under-corrected. However, at the focal plane, the Jupiter still showed the same crisp, sharp and high contrast image, nearly undistinguishable from that of the William Optics. This showed that price is not a determining factor ruling how good the optic of a telescope is.
Of course for some who are looking for the best of the best Maxivision may not be their cup of tea. However for those who are willing to spend only the modest and are looking for maximum performance per dollar, Maxivison is definitely a candidate for their consideration. Think about this – for less than HK$ 3000 you are ready to enjoy a premium feel of an apochromatic triplet telescope which cost more than a double just a year ago.
Best regards
Chan Yuk Lun
测试者：香港镜王陈玉麟先生
“大有可觀” 80 mm f/6 APO 天文望遠鏡 （粗略翻譯）
[ 致：各位天空愛好者，
對于認眞的業餘天文人仕，他（她）們大有可能會購買特佳水平的天文望遠鏡。即是他（她）們會大有可能化費成仟上萬元來購置只是最好的，此最有可能是壹台 ”三塊鏡片組成” 複消色差而品牌是 “Astrophysics”，”TMB”或 “Takahashi” （日本高橋）-----------
對于一位初學者或一般業餘人仕，他（她）們會進行完全不同的步驟。他（她）們只會化費不大，但不幸地大多儀器在這化費不大的價錢水平所買到的可以指定地說是”垃圾天文望遠鏡”，這些”垃圾天文望遠鏡”會顯露出令人難忘的色差或明顯的球面像差或兩者都一齊出現。本來可以恰當地培養天文成為终身興趣，此些”垃圾天文望遠鏡”在將其用者挫敗之後就會被放置在床下或在儲物室內，永遠都不會再見到星星的光了。
無論如何這不是意謂你們不可以用壹個入門價位購得到壹枝作為起始而有質素的天文望遠鏡。中國”大有可觀”(Maxvision)商標剛剛宣佈其生產線將有一系列”三塊鏡片組成”複消色差(折射式天文望遠鏡)及會由可接受而驚人的售價為起點。”大有可觀” 的80mm f/6 裝有”三塊鏡片組成”複消色差透鏡而其售價是驚異地剛剛低于港幣叁仟元。為了測試這枝天文望遠鏡的光學質素，我們將此鏡與壹枝 ”景德”80mm 複消色差折射鏡(William Optics 80mm APO)並列一起觀測木星來壹個甲與乙的比較。”景德”鏡的售價是多于”大有可觀”鏡的2倍，在放大率 110 倍時一如所料此”景德”鏡顯示出壹個明確銳利的木星影像及有十分高的反差，我們隨即轉用”大有可觀”鏡以同一放大率再次觀测木星。
”大有可觀”鏡的色差是如此小量以致實際上不可以用肉眼察覺。以在以焦平面之前及之後的能量或能級來估計會被發現小量球面像差仍然有剩下使致修正不足。然而在焦平面時木星仍然被顯示出壹個相同的明確銳利及有十分高反差的影像，這影像與”景德”鏡的是幾乎被分別不出。這顯出售價不是壹枝天文望遠鏡其光學如何優良的决定因素。
當然如果那些人仕要尋找極之最好的話，那麽”大有可觀”鏡不會是其理想的選擇。然而那些只願意化費不大而要尋得所付出每壹元錢幣要有最高表現的人仕此”大有可觀”鏡肯定是其佳選。如斯想一下以低于港幣叁仟元你就可以高度享受壹枝”三塊鏡片組成”複消色差折射式天文望遠鏡，此類天文望遠鏡壹年前的售價會是雙倍這個。
謹致問候 陳玉麟 ]
TONGKW翻译
Thanks Chanlunlun wrote a report on the telescope.
We also took a Ronchigram of Maxvision ED80 F6
at the same night.
Wongsir
All taken outside focus.
(圖片由subaru提供,Collimation test 儀器由Wah和豆貓設定) |
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置顶卡
变色卡
千斤顶
显身卡
正在我办公室，会和北京同好会的镜子一起发出，对了，你们活动的老规格镜子还天极星了吗？你们的新镜子都准备好了，还不还，代理就无法处理了，谢谢
主要是量，只要达到团购量，应该没问题
