Wer ca. zehntausend Euro zu zahlen bereit ist für ein Teleskop, hätte eigentlich eine Spitzen-Optik mit einem eindeutigen, nachvoll-
ziehbaren Test-Report verdient. Unter diesem Aspekt bekommt der Sternfreund James in USA nicht nur eine Spitzen-Optik, die
handwerklich ohne Tadel ist zu einem sehr günstigen Preis-Leistungs-Verhältnis: Auch als Prüfer hat man seine besondere Freude daran !
Ein Vergleich zum vorherigen Bericht ist durchaus lesenswert!
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This Artificial Sky Test is a wonderful overview to show all optical errors at first: There is no astigmatism, no coma, no spherical, and you can
calculate the optical resolution by this foto and the distance of these three points in the middle. There are lots of reports about this test:

Artificial Sky Test - Anfangsbericht
Einzel-Beispiele zum Artificial Sky Test , F041C Artificial Sky Test bei SC, RC und Cassegrain-Systemen
Das Test-Module bis f/6 Lichtkegel
Refraktor als Foto-Maschine,  Tec 140 +Flattener,
C14-Beispiele; weitere Beispiele; 
F041B Artificial Sky Test Unit für Massimo

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In a second step let's test the quality impression of that triplet lens. Some of us prefere the star test: There is a hardly noticeable colour ring round the
star disc intra- or extrafocal with 270 x magnification.  At the focus you see with 675 x the laser pinhole of 25 micron. The surfase of these discs are white
with no significant texture.

More important are the Foucault-, Ronchi- and the Lyot-test: The Foucault image show at first the Gauß-error (spherochromatism), this one is
bigger than the the Secondary Spectrum, so you'll get sickle-shaped parts of that area: left light blue and right a sandy colour. The Ronchi test
tells you some about the spherical, perfect corrected at green, 532 nm wave the main colour of human eyes. The Ronchi grid is a very small garden
fence with longitudinal slats and gaps between them. This image shows the different surface texture. Otherwise your contrast will break
down with a rough surface.

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Blue is overcorrected, green is perfect and red is undercorrected; http://www.telescope-optics.net/secondary_spectrum_spherochromatism.htm



Foucault Examples,   TS Triplet APO, Foucault different tubes; http://rohr.aiax.de/artifGauss.PNG; http://rohr.aiax.de/@TMB130VuojarviSW_04.jpg
http://rohr.aiax.de/foucault-bilder1.jpg ;   http://rohr.aiax.de/foucault-bilderNeu.jpg ;   http://rohr.aiax.de/FloeVixTMB_21.jpg

Let's get a fringes map at 532 nm wave for a comparison with the LZOS test report.


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The wavefront deviation of that lens: no significant error !


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The typical light energy function - point spread function


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the computer generated fringes map


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differentiated values for astigmatism, coma and spherical



At last my test report at 532 nm wave with the same Strehl value as the LZOS report, next image.


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The Strehl optimum should be at green or e-line (546.1 nm wave) The Gauß error reduces the sprectrum at blue (overcorreted) and red (undercorrected)
This is a feature of all lens optical systems and in our case these a very impressive results.


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I also test the Secondary Spectrum and calculate a RC_index number: http://rohr.aiax.de/@Trav_GW_07.jpg
At first I find out the Power value of every fringes map and convert it to focus difference (FLF)
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In this way I get the Secondary Spectrum and the RC_index number.


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At the end I will compare the lens design diagram, that is ZEMAX generated, an optical design program . . .




. . . and how it could verified by the Artificial Sky Test and by fringes maps for astigmatism and coma errors. At 0.5 degrees
the diagram shows a small astigmatism of PV Lambda/3.7. This means, you can take fotos without any flattener or reducer
till a diameter of 21.22 mm and more. With the Riccardi Reducer this will be corrected for a very large diameter if you will
take fotos of the sky.


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Conclusion:

I was very pleased by testing this extraordinary triplet lens, and James should give me here a short report of these lens, when it arrives him at home in USA.