Gladius CF315 sn 071001 test report – part I

  • Massa, Italy, April 30, 2008


    Dear all,


    First of all, let me tell in a short the history of this telescope as I have records with any.


    The Gladius CF315 telescope serial number 071001 was personally delivered by Lazzarotti Optics company through his own official distributor Unitron Italia to the reseller (and not to the final user directly) on October 22, 2007. The reseller has then delivered the telescope to the final user.


    Lazzarotti Optics received a problem notification by the reseller on November 21, then any appropriate direction was suggested to the reseller to fix the problem. Given the persisting problem, in the Christmas period the telescope was returned from the user back to the reseller for an inspection. On January 29, 2008 Lazzarotti Optics received a report from the reseller notifying the telescope was properly aligned by them and the image delivered was great. From that date on, Lazzarotti Optics heard no longer both from the user and to the reseller until March 26 when appeared mr. Rohr test here.


    According to the reseller, Lazzarotti Optics has returned back this Gladius telescope on April 15, 2008 through the official distributor Unitron Italia because of a persisting optical aberration (astigmatism) was noticed by the user and then verified by mr. Wolfgang Rohr (see mr. Rohr test) throughout this forum.


    On April 16, Lazzarotti Optics found the problem which caused a primary mirror misalignment. Carbon fiber rods used with this telescope had an abnormal ovalization (up to 0.7-0.8mm with the 14mm internal diameter, twice the admitted value here) causing a loosening link between the 2 main parts of the telescope. The aluminum link mechanism couldn’t thus keep safely in place the 2 mirrors from time to time in a random way despite all secondary mirror collimation efforts: the primary mirror misalignment was a not fixable issue by the user.
    The random appearance of this subtle problem explains why it could have escaped both to the Lazzarotti Optics original test and the reseller tests as well.
    Over the following 2 days, rods’ tips were finely rectified and the problem has definitively disappeared over a wide amount of tests performed. The primary mirror holder and other parts involved with mirrors were checked in depth as well and no further problem was found.


    Given the very long Gladius effective focal length (hereafter called as EFL), no artificial star can be successfully used to evaluate such an optical set. A light source placed to close to the Gladius telescope is adding there spherical aberration because the 2 mirrors should work at a different enough distance respect the one established by factory specs. Such a source should be placed at 1/4 a kilometer or so to avoid any aberration adding.
    On April 26, the sky cleared for the first time since the telescope repairing and the stability was good enough to have a decent star test of the repaired Gladius.
    Find it here:



    Some additional note:


    1. Any extraneous stuff added in by mr. Rohr was removed before of the star test.


    2. Images there are a stack of 120 (focus) and 350 (intra and extra focal) raw frames grabbed through a red filter to smooth down as more as possible the atmospheric turbulence. The CCD camera was placed at the Gladius primefocus (EFL=7875mm, image scale=0.18 arcsec/px). More datas are enclosed to the test image itself. A moderate sharpening was applied to put on evidence eventual subtle irregularities otherwise unnoticed in the blurred raw sum image.


    3. The odd diffraction pattern superimposed both to the intra and extra focal images is caused by the circular secondary support and doesn’t introduce any image degradation at all.


    4. Please, take into account this star test was recorded at 8 meters focal length, a 2-4 times bigger EFL than other scopes have. That means a natural amplification of optical aberrations if any is there.


    5. No astigmatism was detected, the 4X enlarged version of the focus image (EFL=31,5 meters!) shows a star as close to the ideal PSF as it could be according to the local seeing conditions. The ideal PSF image was made by Iris software (http://www.astrosurf.com/buil/us/iris/iris.htm) specifying any Gladius parameter (aperture, EFL, image scale, central obstruction and wavelength) involved with the Airy disc drawing process.


    A detailed interferometrical test will follow soon in the part II report.
    Any way, these will just add numbers matching the star test itself introduced here which I personally consider as the key for the true quality estimation. In fact, the star test is made with the telescope working under the real sky looking exactly at the same real objects will be then observed by the users. If a telescope delivers a star image reasonably close to the ideal PSF given for a determined telescope up to an huge focal length (in this case, an amazing 31,5 meters EFL), there is no reason not to be happy with such a telescope, both with the optical set and mechanical parts.


    Lazzarotti Optics sends his deepest apologies to the user who suffered with this problem and it’s promising to have an in-depth inspection from now on also with incoming rods and any else third parts used to assembly a Gladius telescope for the time being.
    Lazzarotti Optics always welcomes any constructive suggestion, comment and feedback to improve his own solutions for You, The very new primary mirror shield (to be released later on next May) just proves that. I don’t like the idea of such a shield (although nicely realized) but I just followed nonetheless what Gladius users wanted.


    Thank you for your attention.


    Paolo Lazzarotti, head of Lazzarotti Optics

  • Basic report: http://www.astro-foren.de/showthread.php?t=9476

    Dear Gladiator_Paolo,

    I just phoned with Massimo, because your zip file didn't work. So I saved it on my server:

    [IMG:http://rohr.aiax.de/Gladius_071001_startest.jpg]

    At first, your star test confirms my simulation with a sphere: Your exposure shows the Poisson dot very impressive:
    http://www.astro-foren.de/showthread.php?p=36137#post36137 This dot I use for aligning Cassegrain systems.

    [IMG:http://rohr.aiax.de/Simulation02.jpg]

    But there is the problem, how to compare our different fotos: My setup was the aligned system in front of a flat and I
    used a 15 mm eyepiece. So I've got a double pass magnification of about 1000 times. (Focus: 7875/15*2 = 1050)
    Would you please tell us, what kind of eyepiece you used for this exposure. So it would be better comparable.
    See also here.
    (I hope, you didn't change the primary. The astigmatism in my exposure looks untypical and we're in doubt, that you can
    solve the problem by rotating the components, what we did.)

    Just one idea: If you take your extrafocal star disk and if you assume this would be a low magnification and if you
    compare this with my extrafocal star disk with a high magnification, these could be comparable and this would be show
    us the same astigmatism.

    [IMG:http://rohr.aiax.de/@315Gladius_16.jpg]

    The next question is: Would you give us a star test of the primary with a short focus eyepiece in Radius of Curvature.
    You can do this extrafocal. May be fixing the primary could be a problem, if so then show me, how you fix the primary
    itself. May be Massimo can take a foto with the Bath interferometer from the primary like this one.

    http://rohr.aiax.de/@315Gladius_09.jpg this was my exposure with the primary in it's "cell"
    http://rohr.aiax.de/@315Gladius_11.jpg this was my exposure out off the "cell" as it shown here.
    I assigned/marked the position of the primary and I didn't change it. Out off the cell, the astigmatism
    was smaller as you see. So fixing the primary in it's cell is a problem. If I test cassegrain systems
    at first I look for the primary in it's cell to exclude any error. So I assume the primary must have
    an astigmatism and I'm interested in testing the primary allone.
    Massimo can do this in this way: http://rohr.aiax.de/@315Gladius_12.jpg
    And this was my result of this fringes map: http://rohr.aiax.de/@315Gladius_13.jpg
    Again the astigmatism is the main problem.

    One more possibility could be that you compensate the primary astigmatism with the secondary by rotating the
    components. If you have a look on my certificate, the main error is definitely the primaries astigmatism. If I subtract
    this, I've got a high strehl value. But if you need a certain position of primary and secondary to one another,
    so make sure, that they cannot rotate in any way. All of it is the reason for the misalignment and not the reseller.

    [IMG:http://rohr.aiax.de/@Beschreib02.JPG]

    You must think about a better fixing the primary, be sure. You cannot say the reseller causes the problems with
    misalignments. Your telescope must arrive the end customer in a perfect state or condition.
    It is only one screw nut what fix the primary and this screw nut is not fixed in any way. This cannot work! The
    primary must be fixed in it's ideal position that it cannot rotate, the secondary, too.

    [IMG:http://rohr.aiax.de/@315Gladius_19.jpg]

    A last note: http://rohr.aiax.de/@315Gladius_02.jpg This connection is not sure and varies the alignment if you move the
    telescope.

  • Dear mr Rohr,


    I had some problem to post here the JPG image directly, I'm not sure why.
    Any way, now you could look at it.


    When a photodetector (still camera, CCD camera, webcam, etc.) is applied to a whatsoever optical device (photo lens, microscope, telescope, etc.) the magnification as used with eyepiece is a nonsense. The image scale is useful for this purpose.
    Just an example: if you apply 2 different cameras featuring very different pixel sizes in the same telescope you'll get 2 different image scales. The camera featuting the smaller pixel size will get a smaller image scale, say an higher magnification. But there's no match with eyepiece magnification. At the best, you can have a rough approximation with an equivalent eyepiece focal lenght, but this leaves much to be desired.


    Of course, I didn't change the optical set for a simply reason: the star test tells it's OK!
    On today I'll meet Massimo and we'll also test the primary mirror by alone, both in its own holder and as from your setup. Exceptionally, I'll attach photos of his own setup showing the Gladius under testing.
    Any way, if the star test grabbed @ f/25 is good, the primary mirror by alone should be theorically 6 times better. Once removed the 6x amplification given by the secondary mirror geometry, I expect a very good optical quality out of that mirror. I'll be back to you soon (part II report) with any test in my hands.
    As told in my reply, I don't care that much of intra and extra focal images - telescopes are never used out of focus!


    I won't get a dedicated star test for the primary mirror by alone, the interferometrical test will be more than enough. The telescope must be used as is (f/25 focus) by the user, not at the f/4 primary focus!


    I can definitively exclude the astigmatism was cleared out by rotating mirrors! While making the star test, I rotated many times the secondary mirror in order to pristine the proper focus position. The original backfocus has changed a lot because I removed the thin film you applied there in the back face of the primary. Further, given the Gladius' very long f-ratio, I had to rotate the secondary mirror also to get such defocused (intra and extra) images. That's a clear evidence the astigmatism is not related in any way to the mirror angular position.


    I agree with you about the threaded golden ring blocking the primary mirror in place. In fact, I just added a mechanism which always allows the same pressure when assemblying/disassemblying the primary mirror for a safe trip.
    I'll send a close-up picture of this modification as soon as possible.


    Hear you later, I've to drive up to Massimo right now!

  • http://forum.astrofili.org:80/viewtopic.php?t=26392

    My dear Paolo_Gladiator,

    yes, a Gladiator is fighting with a gladius :) . . . but here we need good arguments.

    We discuss the accuracy of the optical system at first and later some features of the "optical tube". Both with some
    errors and I just want to help you, to optimize this system - if you accept, I'm not sure!

    At first how to bring fotos in this report:

    [IMG:http://rohr.aiax.de/@image_in_report.jpg]

    Zitat

    When a photodetector (still camera, CCD camera, webcam, etc.) is applied to a whatsoever optical device (photo lens, microscope, telescope, etc.) the magnification as used with eyepiece is a nonsense. The image scale is useful for this purpose.



    You definitely try to make an X for U as we say in German, this is an old Latin saying and I hope, you will understand.
    You are talking up the facts. If you test the primary with Massimos interferometer in the way I showed in all my reports,
    so you will see the optical error. Test your Gladius as consequent as we did, and you will see the problems - otherwise
    no German customer will buy this telescope from you.

    Now the differences: I take an eyepiece of 15 mm in the focuser and put the system in front of a flat. So I get a high
    magnification and in this case I can align the system very exactly and I see all the errors of this system and take a
    foto of it. You take the system without an eyepiece in the focus and so you cover the astigmatism. But your own upper
    exposure extrafocal (see your report) shows the astigmatism in the same matter. The customer in German note this,
    the reseller in German note this too. But you will not note the astigmatism.

    The problem is not our way of testing your telescope (definitely a hard test) the problem is that it didn't work at the
    end customer - and Mr. Ackermann will not pay 7.000.- Euro for nothing.

    Publish the basic fringes map of this telescope in autokollimation setuphere - we can calculate it. If you are
    interested in a certificate with a Zygo, we will do that. Then we'll test with the ZYGO the primary at first and then
    the Dall-Kirkham System in front of a flat with high accuracy.

    I'm more and more interested in your testing equippement . . .

  • Der Sterntest den Paolo gemacht hat zeigt doch ein deutlich elongiertes Beugungsbild im Extra- und im Intrafokalen. Wäre das Astigmatismus, müßte es jeweils um 90° gedreht zu sehen sein. Im Fokus ist davon dann kaum was zu sehen, nur einen ganz leichten Lichtausbruch nach rechts oben gibt es. Das passt doch meiner Erfahrung nach überhaupt nicht zusammen. Habe selber schon zig Sterntest an vielen versch. Teleskopen gemacht, aber sowas komisches ist mir noch nicht untergekommen. Gibts dafür eine logische Erklärung? Handelt es sich etwa um eine besondere Art der Verspannung? Bino-Tom

    Bino-Tom


    <a href='http://www.binoviewer.at' target='_blank'>http://www.binoviewer.at</a>
    <a href='http://www.binoviewer.at' target='_blank'><img src='http://www.binoviewer.at/images/banner.gif' border='0' alt='user posted image' /></a>

  • Darüber, lieber Tom, bin ich ebenfalls gestolpert. Das erste Problem ist die Vergleichbarkeit unserer Messungen.

    Während ich über das Autokollimations-Setup und über das Okular von 15 mm in eine hohe Vergrößerung komme, die allerdings wirklich alle Fehler zeigt (egal bei welchem Test) macht Paolo lediglich direkt im Fokus (intrafokal-fokal-extrafokal) seine Aufnahmen und kaschiert erst einmal eine Reihe von Fehlern. Ein weiteres Mal optimiert er die Situation durch Bild-Addition - während es sich bei mir um jeweils eine Aufnahme handelt bei perfektem Seeing auf der opt. Bank.

    Die größte Ähnlichkeit hätte noch seine extrafokale Aufnahme mit der meinigen, die bei ihm sehr viel freundlicher ausfallen muß. Eigentlich müßten bei seiner Vorgehensweise die Sternscheibchen absolut rund sein. Für den Hauptspiegel bräuchte er dringend einen Astigmatismus-Ausschlußtest, weil selbst der kleinste Astigmatismus über den Fangspiegel kräftig nachvergrößert wird. Und da kommt die Hauptspiegel-Lagerung in die Diskussion: Es geht einfach nicht, die plangeschliffene Rückseite des Hauptspiegels direkt auf eine Metallscheibe zu legen und dieses System durch eine einzige Hülse zu befestigen, die von hinten durch eine Mutter gehalten wird an der wiederum der Fokuser hängt. Damit ist der Hauptspiegel nicht gegen Verdrehung gesichert. Auch ändert sich der Druck auf den Hauptspiegel, weil auch die Mutter nicht fixiert wurde und entweder zu locker oder zu fest sein kann. Daß die Hülse vorne auf die Kante der Hauptspiegel-Bohrung drückt, streitet Paolo ebenfalls ab. Man würde es aber erkennen wenn man sich die Hülse vorne einmal genau anschaut: Der Teflon-Ring muß beim aktuellen Teleskop dicker sein. (Hat er aber alles wieder "removed" und damit in den alten unhaltbaren Zustand versetzt.) Da der Hauptspiegel selbst nicht justierbar ist, es es fraglich, ob der Hauptspiegel wirklich exakt auf den Sekundärspiegel "schaut". Wenn der Hauptspiegel nämlich nicht exakt auf der Achse sitzt, dann stimmt wiederum das Sternscheibchen nicht: Man kann zwar das System exakt kollimieren, bekommt aber dann einen dezentralen Ausschnitt vom Sekundärspiegel und den sieht man dann am Sternscheibchen. (Bei einem Newton kann man das ebenfalls beobachten, wenn der Fangspiegel versetzt eingebaut ist und nicht die ganze Fläche des Fangspiegels verwendet wird.)

    Während von meiner Seite die unterschiedlichsten Tests immer auf den gleichen Sachverhalt hinweisen, vermisse ich bei Paolo ein Interferogramm vom Hauptspiegel selbst und ein Interferogramm in Autokollimation selbst. Daß er sich angegriffen fühlt, ist eigentlich klar. Nur unser Sternfreund Ackermann erwartet für 7.000.- Euro eine Optik, mit der man hochwertige Planeten Aufnahmen machen kann, wie es in der Werbung von Lazzarrotti gezeigt wird. Mit dem aktuellen Gerät jedenfalls war das nicht möglich.

    Prinzipiell geht es um den Versuch, die Kinderkankheiten dieses Teleskopes auszumerzen. Das ist nur leider noch nicht angekommen.

  • Ich habe einen Kunden der hat sich nun einen UK 300 mm OMC zugelegt, kämpft dort mit justierproblemen und hat sich nun von Paolo überzeugen lassen trotz des berichtes hier, der meinem Kunden bekannt ist ein solches Teil zu kaufen, da Ihm Paolo absolut beste Qualität versprochen hat, nur so nebenbei

    grüße
    Markus

  • Hallo Markus,

    Zitat

    Ihm Paolo absolut beste Qualität versprochen hat, nur so nebenbei



    Wurde den Ackermanns auch versprochen, siehe hier. Soll doch Dein Kunde seine Planeten-Aufnahmen hier einstellen. Eine bessere Werbung gäbe es nicht für den Gladius.

    Übrigens sind die beiden Systeme höchst verschieden. Lazzarrotti-DallKirham ist ein f/25 System, das von Orion UK ein f/6.8 System.

  • Hallo Leute!


    Lese bei den Berichten zu diesem Teil schon einige Zeit kopfschüttelnd mit:sad:
    Also, was soll man dazu sagen. Nicht nur daß das Teil optisch alles andere als berauschend ist, auch das Design sagt eigentlich schon alles aus. Das Teil ist nicht für die Astronomie geeignet, sondern für irgend eine Vitrine eines Neureichen, dar nicht weiß was er mit seinem Geld anfangen soll. Ich baue nun schon seit sehr langer Zeit Teleskope und Montierungen. Aber was der da alles an seinen Designdingern falsch macht, das ist auch schon eine Leistung. Allerdings eine schlechte Leistung. Immer wieder gibt es Neunmalkluge, die regelmäßig das Rad neu erfinden. Bevor man etwas Neues entwickelt, sollte man sich mal bestehende Konzepte ansehen. Die Teleskopbauer die früher was entwickelt oder gebaut haben, waren halt auch keine Deppen. Und dann der Versuch, mit allen möglichen Erklärungen das Ding gutzudiskutieren, das ist leider auch der falsche Weg.


    Gruß
    Richard
    www.observatorium.at
    www.gierlinger.cc

  • Dear mr. Rohr,


    I could see more deutsch replies from other german people here which I can't understand at all - on-line traducers don't work, translated contents aren't clear yet at all.
    So, I can reply to you only.


    http://forum.astrofili.org:80/viewtopic.php?t=26392

    My dear Paolo_Gladiator,

    yes, a Gladiator is fighting with a gladius :) . . . but here we need good arguments.


    I've as many arguments as you want! ;)
    The star test I submitted a while ago it's the best one because:


    1. It's clear to everyone, no complex interferograms to decript.


    2. It says how the telescope really performs in its own environment, the sky.


    3. It's easy to reproduce - any user can verify this control. Interferometricals controls aren't accessible to common people.



    We discuss the accuracy of the optical system at first and later some features of the "optical tube". Both with some
    errors and I just want to help you, to optimize this system - if you accept, I'm not sure!


    Aren't you sure yet?
    That's odd, I just wrote in underlined lines I welcome any tip, suggestion and feedback in getting my solutions as improved...



    You definitely try to make an X for U as we say in German, this is an old Latin saying and I hope, you will understand.
    You are talking up the facts. If you test the primary with Massimos interferometer in the way I showed in all my reports,
    so you will see the optical error. Test your Gladius as consequent as we did, and you will see the problems - otherwise
    no German customer will buy this telescope from you.


    I just have a solid certainty: everyone's responsible of his own actions and only people will get his own conclusions. Not yourself or myself.
    My action here is to clarify facts happened around a telescope of mine's and nothing else. This is due by my side.
    In addition to that, I'm taking the advantage of hearing feedbacks to improve solutions which aren't perfect yet and reject any falsity.

    Now the differences: I take an eyepiece of 15 mm in the focuser and put the system in front of a flat. So I get a high
    magnification and in this case I can align the system very exactly and I see all the errors of this system and take a
    foto of it.


    The same I did. That's the procedure.


    You take the system without an eyepiece in the focus and so you cover the astigmatism. But your own upper
    exposure extrafocal (see your report) shows the astigmatism in the same matter. The customer in German note this,
    the reseller in German note this too. But you will not note the astigmatism.


    First of all, whatever you add in the optical train adds aberrations in. That's obvious because simply doesn't exist the perfect mirror and the perfect lens.
    That means my own star test is more reliable than your's one because I captured the signal as coming out from the 2 mirrors the Gladius is made by!:) I'm pretty sure your optical devices are top quality, but the lack of these is better, isn't it? ;)


    Myself and Massimo got stuff enough to tell the primary mirror holder works flawlessly and the primary mirror star test delivered a perfect Airy disc.
    Given the huge stuff to be processed yet, the part II test report by myself will take some time. We got both a star test and an interferometrical test as from your directions. I'll be pleasured to show you any.
    I kindly ask some patience.


    I just want to remember for everyone's clearance that mr. Rohr has tested the Gladius in question with the primary mirror as misaligned (it has arrived here in such a situation), hence the horrible test report.
    Massimo has tested again this telescope (the first time was on last October) with the defective part repaired and optics aligned.
    The huge difference with our own results is so clear.


    We'll have just to clear the difference with the primary mirror measurement because we didn't notice ANY noticeable difference in having the mirror placed in the Gladius holder or held externally to the Gladius as mr Rohr did.
    Once cleared this issue, there will be nothing else to say.

    The problem is not our way of testing your telescope (definitely a hard test) the problem is that it didn't work at the
    end customer - and Mr. Ackermann will not pay 7.000.- Euro for nothing.


    I just sent HERE my PUBLIC apologies to the customer and explained what has happened there to his telescope.

    Publish the basic fringes map of this telescope in autokollimation setuphere - we can calculate it. If you are
    interested in a certificate with a Zygo, we will do that. Then we'll test with the ZYGO the primary at first and then
    the Dall-Kirkham System in front of a flat with high accuracy.

    I'm more and more interested in your testing equippement . . .


    I have interests in having relationships with people making their job as I do. That means persons always wishing to improve themselves through an humble approach to the Knowledge, recognizing their own limits and loving to share their own knowledge to the next door person without imposition.
    Once satisfied this criterion, you'll have my full approval.

  • Dear Paolo,

    let's make it short:

    Whatever you tell us, fact is, your own star test is not OK. This one is your one:

    [IMG:http://rohr.aiax.de/@315Gladius_53.jpg]

    And this telescope causes astigmatism like my star test or like the star test from Ackermann. Therefore Mr. Ackermann did not get the expected telescope. That's all. And I showed with consequent tests what the reseller noted and what Mr. Ackermann noted. And we hope, this was the only Gladius, what did not work.

    You are invited to send me a perfect one - may be the customer you promised a perfect one - and I test this second one again and write a report to show, how perfect the other Gladius could be.

    I allways test individual telescopes - no more.

    http://www.flippi.de/out/oxbas…/dyn_images/1/4653_p1.jpg

  • Dear mr Rohr,


    Yeah, I'll make it even shorter: I'll add nothing but an image which was somewhat promised by myself on April 10 when I wrote:


    I'll fix the problem with the (ex) Ackermann's Gladius and if weather will allow me to get some nice seeing, I'll get similar results. Stay sure.


    On May 2nd I used the old Ackermann telescope (now repaired) featuring its original optical set to take a Saturn image under a fair seeing but low transparency caused by thin cirrus. The poor rendition with belts and colors was due to this.


    http://www.lazzarotti-hires.co…urn20080502_1929_lazz.jpg


    A single RAW FRAME and the unprocessed FIT image can be downloaded HERE


    Right now, I've nothing else to add here about this history. That's all.
    But I'll be pleasured to reply to asking people for their clearance.


    Thank you all for your patience and have fun under the starry sky! :happy:

  • Dear Paolo,

    Zitat


    I'll fix the problem with the (ex) Ackermann's Gladius and if weather will allow me to get some nice seeing, I'll get similar results. Stay sure.
    On May 2nd I used the old Ackermann telescope (now repaired) featuring its original optical set to take a Saturn image under a fair seeing but low transparency caused by thin cirrus. The poor rendition with belts and colors was due to this.



    You create your brilliant fotos in your computer

    first you confess there was a problem with this telescope and four independent persons note this before.
    second what kind of problem was it? I'm interested.
    Third did you think about to avoid this in future? Otherwise they bring their telescopes to me.
    Fourth this is not a proof about the optical quality. Why?

    I know the optical quality of most of the SC-systems. If I compare your saturn exposure with some fotos from any SC' systems and how they optimize the frames in the computer. There is a big difference between the optical quality and how the computer optimize it. So your Saturn foto is a proof of your computer program but not of the optical quality of your telescope. This thread just show you are excellent in taking fotos of planets with "normal" telescopes.

  • Dear Wolfgang,


    I described the problem HERE, please read carefully my first message of this topic.
    Of course, it's in my obvious interest to solve ANY problem. I'm not that sadic to leave customers by alone!


    Last, neither the most experienced and skilled imager can get such an image out of junk. It should be likely to get a diamond out of the glass.
    Softwares running in PCs simply sort raw frames by quality, get those stacked and sharpened. Those are all mathematical operations performed over the original signal. If the signal is good, the final image will be good. If the signal is "broken" by an optical aberration which is costant over the time as astigmatism, the image will show that aberration. If the signal is "broken" by a random atmospherical aberration, the averaging helps a lot in minimizing that "aberration". Here, too, 1+1=2 with no exception or magic. This is the only optimization we get back from softwares!
    Unfortunately, the "magic software" turning an aberrated 100mm telescope into a gorgeus 1 meter telescope has yet to be invented...
    Imagers are still waiting for this piece of software. Myself included.
    Deconvolutions aren't good at all to correct aberrations over planetary images, those are somewhat valid for deep sky objects only.


    I lately added here a couple of raw and unprocessed frames as they were captured by my CCD camera. If you don't believe to the processed image for your own reasons, you must believe to these ones then.
    A 1 lambda astigmatism would turn Saturn moons into crosses, the Cassini division (1 arcsec wide) into a very asimmetrical dark line with ANY raw frame I used! Here you can just notice local atmospherical turbulence effects and nothing else.


    I'm all but saying such mirrors are perfect, I'm just showing those are delivering a quality as from my quality declaration.


  • Dear Paolo,

    is it a problem for you, to repeat the reasons for that astigmatism or to give us a link for the reasons of that?

    How you support your customers I can read it here:

    All the tests showed astigmatism, definitely all and you know that, so I'm really interested how you kick out that error, what is documentated by all persons who tested this telescope from the beginning. I have them all.

    Für die deutschen Mitleser:

    Zusammen mit Paolo selbst sind es fünf Tester, die einen Astigmatismus attestiert haben, deren Ergebnisse mir alle vorliegen. Wie also dieser Astigmatismus urplötzlich verschwinden kann, ohne daß man den Hauptspiegel austauscht, bleibt das Geheimnis von Paolo Gladiator Lazzarrotti. Von Seiten Paolo wurde nie ein nachvollziehbares Certifikat vorgelegt. Tatsächlich liegt mir ein fremdes Interferogramm vor, was meine Ergebnissen (Hauptfehler Astigmatismus) durchaus bestätigt. Nationale Befindlichkeit mag seine emotionale Reaktion noch verstärken. <== In Italien fanden diese beiden Threads hohe Beachtung.

    Paolo Lazzarroti stellt seine Optiken nicht selbst her und muß sich daher auch auf die Qualitätsangaben seiner Lieferanten verlassen. Damit hat das von ihm beigelegte Certifikat keine meßtechnisch Relevanz, die Quantifizierung ist also völlig aus der Luft gegriffen. Eine Bestätigung findet dieser Sachverhalt auch hier:

    Zitat

    My next step is to make it tested by a professional optical institute capable of releasing a legally valid certificate.

    Das hat ihm auch Ackermann dringend an Herz gelegt.
    Die Qualität seiner Planeten-Aufnahmen entstehen im Computer und der Nachbearbeitung seiner Rohbilder. Auf einer der Würzburger Frühjahrstagung konnte ein Referent zeigen, wie man auch mit fehlerhafter Optik brilliante Planeten-Bilder "zaubern" kann.

  • Dear mr Rohr,


    The repaired telescope delivers amazing results as my own Gladius do. Documentations shared here (star test, Saturn image) simply say this telescope is NOW ok, not before when it was in mr Ackermann's (and your's) hands. Again, my apologies to the customer.
    I kicked no astigmatism out of mirrors (if one day I could do so, I would be a superman!), I just properly realigned the primary mirror which arrived here quite misaligned because of the problem widely described here causing the astigmatism you measured. Nothing more, nothing less.


    I repeat nothing because people here might be bored by hearing once again my reasons. Simply look back at my first message where I wrote a very detailed report of things happened.


    My replies here to you have come to an end. I'll be pleasured to let you have the final reply. See you at Essen.
    As latins would have said, verba volant, Gladius manet.

  • Dear Paolo,


    I accept your apologies. But at the end of the road we decided to reject the Gladius. Next time we will choose an other instrument. After all the discussions it is not clear (or believable) to me what really cause the astigmatism. It seems to me that the Gladius was not functional from the very first. Nevertheless, you must improve your outgoing inspections. It cannot be that you must visit every customer for delivery. And I recommend you to support your customers in a better way, independent from nationality. Maybe that Germans more fussy than other.


    Best Regards


    Jörg Ackermann



    PS: Very many thanks to Wolgang Rohr. We have learned many things about optical tests from you. Without your help we had never circumstantiate the problems.

  • Dear mr Ackermann,


    Thank you so much for accepting my own apologies!


    You can learn about the problem with your telescope HERE
    For your clearance, the huge astigmatism was thus caused by the primary mirror misalignment. I state once again the primary mirror has a residual of astigmatism but this is lower than the declared limit I guarantee.
    My next step is to make it tested by a professional optical institute capable of releasing a legally valid certificate.


    Hope you could have looked at the Saturn image I posted here which IMHO is worth of hundreds and hundreds of words. I know you're valued imagers (I still remember your gorgeus Venus image taken with a 180mm Maksutov! Nothing short of amazing, my sincere congs!) so you can better understand the real potential delivered by this telescope once working OK.
    Given the problem occurred (now succesfully repaired), yes, I agree this telescope could have delivered the astigmatism since the first time. I'm not sure yet how this couldn't be detected by the reseller whose knowledge is top notch. My support to him was prompt any time this was asked to myself (the same happened to you directly). Any way, I'll train him to have in depth inspections with the Gladius in order to fix eventual problems as fast as I did. I think this should avoid such an evenience over the time being.


    Of course, the Gladius design allows the mirror alignment to be kept safe also when disassembled and shipped everywhere. It would be a mess by my side if this wouldn't be true, isn't it?
    About this particular item, a part didn't work as expected causing any trouble.


    Any way, I honestly accept your choice not to consider a Gladius.
    I just hope to meet you in person at Essen fair to clarify further. Frankly speaking, there's no better way to do so.


    I always deal with people without looking at their nationality, that's obvious!


    Best regards and best luck with your imaging work!