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
