如何進行室內星點測試
發表於 : 2010-03-02, 04:10早前我們用人工星點進行了一個室內測試，由於人工星點距離望遠鏡在焦距的40x範圍，球差影響已儘量降低， viewtopic.php?f=5&t=63 不過最理想還是建立一個平行光管(Parallel beam collimator)，以目前我手上最合適的工具包括APM-TMB 254 f9 APO，又或者用一台修正度更高的 APM-TMB 130 f9.25 APO都可以。Markus Ludes是德國APM的負責人，我在他的店裡看過一台很大口徑的反射鏡用來做collimator，因為他亦很喜歡做室內星點測試，這裡有38台市面上所常見的望遠鏡星點測試結果： http://aberrator.astronomy.net/scopetest/index.html
以下是一些我早前跟他談及的技術內容：
1. the apochromatic projector lens I use is a Takahashi Hi 2.8 mm 0.965" ortho in reversed way insert into the focuser , so it works like a projection lens and thats makes the lightsource not only flat but also much smaller then 50 micron
2. I have had a 500 mm flat but never used it. The alignment of the telescope against the flat must be done ultraprecision and taking even optical experts partly hours before they can do the startest.
3. LZOS do the alignment work until they reach in the test the guaranted quality or better , but never to perfection, because it cost hours and LZOS say none pay this extra work.
4. here is a much better tester then Mr. Rohr, Its Mr. Schreckling, see here http://www.astrotreff.de/topic.asp?TOPIC_ID=95328&whichpage=4 he tested 2 p 130/1200 with LZOS report of about 97 % strehl and his report of 99% after taking the time of perfect alignments
5. I use a collimator to make the startest in single pass , single pass is what customers see at sky. A startest in double pass kill even the most perfect optics. Customers are able to compare a single pass startest with what they see at sky , thats what is important to me therefore I use a collimator.
6. You can also use a good apo , like the 10" against that you can test perfect any smaller up to 10" diameter apo very critical
他叫我把254APO拿出來作為平行光管 (Parallel Beam) 來做室內星點測試那些小鏡，是否有點過份
以下是一些我早前跟他談及的技術內容：
1. the apochromatic projector lens I use is a Takahashi Hi 2.8 mm 0.965" ortho in reversed way insert into the focuser , so it works like a projection lens and thats makes the lightsource not only flat but also much smaller then 50 micron
2. I have had a 500 mm flat but never used it. The alignment of the telescope against the flat must be done ultraprecision and taking even optical experts partly hours before they can do the startest.
3. LZOS do the alignment work until they reach in the test the guaranted quality or better , but never to perfection, because it cost hours and LZOS say none pay this extra work.
4. here is a much better tester then Mr. Rohr, Its Mr. Schreckling, see here http://www.astrotreff.de/topic.asp?TOPIC_ID=95328&whichpage=4 he tested 2 p 130/1200 with LZOS report of about 97 % strehl and his report of 99% after taking the time of perfect alignments
5. I use a collimator to make the startest in single pass , single pass is what customers see at sky. A startest in double pass kill even the most perfect optics. Customers are able to compare a single pass startest with what they see at sky , thats what is important to me therefore I use a collimator.
6. You can also use a good apo , like the 10" against that you can test perfect any smaller up to 10" diameter apo very critical
他叫我把254APO拿出來作為平行光管 (Parallel Beam) 來做室內星點測試那些小鏡，是否有點過份
