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Ruud

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  1. Thank you for responding Alexander.

    Part A - windowed mode

    The GL jagged edges problem only exists full screen. In a window everything looks fine.

    This is 0.19.3 open GL in a window at 150% scaling, it looks just fine:


    825822326_GLwindowedat150scaling.thumb.png.aa638538f07ad705570ae39cd350ce7a.png

     

     

     

    Part B - Full screen mode

    The problem only exists full screen. Please view everything at actual pixel size to get rid of the moirée.

     At 150% scaling the difference is obvious in the text and even in the constellation lines. It may be there in everything.

    1004744523_150GLandANGLE.thumb.png.bcdb8cf1feb343fd7bf8a84237c0d5df.png

    zips of  original pictures: 100% scaling ANGLE and GL.zip   150% scaling ANGLE and GL.zip

    At 100% the fonts look fine in both GL and ANGLE. The constellation lines are a little different though, but this is not obvious at a normal viewing distance. See the 100% zip.

    I'll be happy to do more testing if you want me to.

    NB. The pixels are about 0.15mm wide.  I'm trying out purple constellation lines. I think I'll try dim grey next.

     

  2. (Russian below / Русский ниже)

    Hello Alexander, happy 2020, now or if you prefer in two weeks.

    Today I tried stellarium 0.19.3 and noticed that anti-aliasing no longer worked. I use the program on a 4K monitor, with Windows font scaling at 150%.

    So I went back to 0.19.2, but the anti-aliasing did not come back. I installed 0.19.3 again and tried ANGLE Direct3D 11. That makes the fonts look good again.

    The problem is solved, but open GL has always worked fine for me. Is there anything I can do to make Open GL work properly again? I use windows10 64 bit,  NVIDIA GTX 1060 with 3GB memory and an LG monitor (27UD69P). All drivers are up to date.

    Thanks!

    Здравствуйте, Александр, счастливого 2020 года, сейчас или, если хотите, через две недели.

    Сегодня я попробовал стелларий 0.19.3 и заметил, что сглаживание больше не работает. Я использую программу на мониторе 4K, с масштабированием шрифта Windows на 150%.

    Поэтому я вернулся к 0.19.2, но сглаживание не вернулось. Я снова установил 0.19.3 и попробовал ANGLE Direct3D 11. Это снова заставляет шрифты выглядеть хорошо.

    Проблема решена, но open GL всегда работал нормально для меня. Что я могу сделать, чтобы снова заставить Open GL работать должным образом? Я использую 64-разрядную версию Windows10, NVIDIA GTX 1060 с 3 ГБ памяти и монитором LG (27UD69P). Все драйверы обновлены.

    Благодарность!

  3. Hi

    2 hours ago, MartinHiggins said:

    Thanks for the Quickmap link. Is it possible to reverse the poles which is the view I have with my scope? I've read the user guide but can't find a mention of this.

    I looked but could not find any way to do what you want. This may be because all the data is NASA imagery, and NASA traditionally puts North on top in all published images. Who knows, the Quickmap team of Arizona State University might be willing to add a South up option in the next update of the website. Have you tried Quickmap's 3d globe? See here, it gets very 3D even on a normal screen.

    At least the SVS Moon has a South up version. Here's a screenshot of that...
    2020-01-01_.thumb.png.baffd4db50e78b4741486724e901a6cb.png

    • Like 1
  4. An extension tube will give you an upside down view (rotated  over 180°). If the tube is too long you can no longer focus on infinity. The one you link to would most likely work just fine.

    In combination with a diagonal, an extension tube can be used for close range focusing. I use one to turn my scopes into long distance microscopes.

    There are 45° prism erecting prisms, which bring you halfway to straight through. The image quality suffers somewhat from them, which you may not notice at low magnifications.

    Straight through porro and roof prism assemblies are used in binoculars. I don't know if these are also made for telescopes. Again, the light path through them might get too long to reach focus at infinity, but if you focuser has plenty inward travel you are probably OK. If not, use a Barlow instead. A Barlow moves the focal plane of the telescope out.

    The tube you link to looks a lot like a Barlow with the lens removed. If you have a longish Barlow you can experiment a bit, with and without the lens.

     

    • Thanks 1
  5. Thank you Dave, for sharing your impressions. You are no doubt right! Most diagonals perform equally well.

    There's good reason to expect why this is the case. Suppose your old diagonal has 95% reflection and is otherwise good. You will see no perceptible gain from moving to a 99% diagonal. The gain will be 2.5 x log(99/95) = 0.045 magnitudes. You'll not notice that.

    Mirror flatness isn't all that important either. The light of each part of the view reflects off only a fraction of the mirror. Here is the light of one star reflecting of a diagonal that is far from flat:

    Wavefront.png.453fdc61fe3fecb2c3b1ed31882dace0.png
                                                         undulated diagonal surface

    In practice, if a mirror is 1/10th wave overall, it is 1/40th wave effectively when it comes to reflecting the light cone of a star. Even reflecting the light cone of a planet involves only a minor portion of the mirror, though it will be larger than that of a star and some minor image degradation may result from this. Nothing much to notice here either.

    What matters more than extreme reflectivity or extreme flatness is the roughness of the diagonal. The smoother, the less scatter. You will notice scattered light as halos around bright stars and planets. Microscopic scratches from cleaning are a source of roughness on mirrors.

    I bought my first replacement diagonal to take the place of an old aluminium enhanced (overcoated) Televue diagonal. Twenty years of cleaning had taken its toll on its surface. There was a small dull spot to the side. I got a dielectric one because that can withstand casual cleaning without getting scratched. It's wonderful for that reason! It will not turn rough over time an although theoretically a dielectric mirror starts off with a tiny bit more scatter than an especially smooth overcoated aluminium one, in the long run a dielectric mirror is a better choice. (That's a personal opinion, I know, but  star diagonals do require regular cleaning and I want cleaning to be fast and easy without worry.)

    When I got a Nexstar 6SE, I replaced it's diagonal as soon as I could. It suffered from an enormous amount of scatter. Very poor polishing  on that one! Flatness was okay. The dielectric replacement was an enormous improvement!

    • Like 2
    • Thanks 1
  6. I'd go for the Morpheus 17.5 because that's an epic eyepiece which one needs to have anyway (because it is so engaging). It has a nice wide field with good eye relief, a well behaved exit pupil and great contrast and sharpness. It's an immersive and comfortable eyepiece. You'll certainly use it a lot.

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