loading
3
17Instructables55,768Views61Comments
I'm a guy from Hungary. Musician, amateur astronomer, DIY-fan, airplane-fan, etc. My hobbies are important for me. In my home country the DIY-concept is an old tradition, so I became a fan in my early years.

Achievements

10K+ Views Earned a bronze medal
Show 0 More »
  • BigCthulhu's instructable Build Stork, the Easy But Amazing Flying Wing!'s weekly stats: 3 weeks ago
    • Build Stork, the Easy But Amazing Flying Wing!
      2,027 views
      81 favorites
      2 comments
  • SIMPLE BUT PROFESSIONAL TELESCOPE FOR BEGINNER ASTRONOMERS

    Hi, mohanbhai! The formula is simple: if you know the focal lenght of the objective lens (the bigger one toward the sky) and the eyepiece (at your eye when observing) you should do a simple distraction: F obj / F epc = Magn.The diameters are not so interesting when counting magnifications, but the diameter of the objective lens determines the resolution of your scope - the bigger diameter increases the resolution and light gathering ability with a quadrant ratio (sorry, I'm not a native in English, too:-)) - that means the 2x diameter gives 4x resolution and light gathering. The magnification depends only on the focal lenght of the obj. and the eyepiece with their ratio in a telescope.If you have a telescope that you want to determine, and there is not any given value on its case or bod...see more »Hi, mohanbhai! The formula is simple: if you know the focal lenght of the objective lens (the bigger one toward the sky) and the eyepiece (at your eye when observing) you should do a simple distraction: F obj / F epc = Magn.The diameters are not so interesting when counting magnifications, but the diameter of the objective lens determines the resolution of your scope - the bigger diameter increases the resolution and light gathering ability with a quadrant ratio (sorry, I'm not a native in English, too:-)) - that means the 2x diameter gives 4x resolution and light gathering. The magnification depends only on the focal lenght of the obj. and the eyepiece with their ratio in a telescope.If you have a telescope that you want to determine, and there is not any given value on its case or body about the focal lenghts, you can use the "poor man's way" to get the magnification: look in the scope, and find an object to estimate the field of view; a roof with tiles, a distant fence, a brickwall, or any multiplicated object which is repeated periodically. Now count or estimate the number of the parts (bricks, tiles, fence rods, etc.), which are seen at the diameter of your field of angle, and turn your scope, look in it from the larger objective lens, to see a small light circle with a very small image at the end of it. Now you should estimate again the number of the parts, (the bricks or tiles), in this circle. This is the all, the ratio of the two numbers gives the magnification: for example you can see 32 fence rods or roof tiles in the scope at the diameter line of the f.o.v., and 3 rods looking from the other side, then your scope has cca. 10x magnification. For a more exact result try to use a stativ or tripod to avoid the errors causing the hand holding moves.Fhtang!

    View Instructable »
  • BigCthulhu commented on 103366's instructable Super Simple Card Trick2 months ago
    Super Simple Card Trick

    And if you can perform it well, you are better than the Masked Magician, who has failed this trick in a live tv-show. https://www.youtube.com/watch?feature=player_embedded&v=j8tQgHiMGGU

    View Instructable »
  • BigCthulhu commented on Dragwyr's instructable Magic Spell Book2 months ago
    Magic Spell Book

    I made it! Some improvements I recommend: I made a smaller book, with this size my thumb must move smaller (as seen on the pictures), and this is hardly noticeable. I trimmed the edges at the spine from top to bottom, and with this method the rolling edges kept their line, only the angle was changed a bit. And I printed the sheets with ancient fashioned worn and darkened edges, because this may cover the differences between the odd and even pages. When using, I don't roll it at the corners; it's enough to roll the pages with somewhere at the center, upper or lower a bit - nobody can even notice the difference. And my story is the next: the Necronomicon is the most dangerous and demonic tome ever, and nobody can read from it out of a pentagram - I roll the empty pages to DEMONstrate :-) ...see more »I made it! Some improvements I recommend: I made a smaller book, with this size my thumb must move smaller (as seen on the pictures), and this is hardly noticeable. I trimmed the edges at the spine from top to bottom, and with this method the rolling edges kept their line, only the angle was changed a bit. And I printed the sheets with ancient fashioned worn and darkened edges, because this may cover the differences between the odd and even pages. When using, I don't roll it at the corners; it's enough to roll the pages with somewhere at the center, upper or lower a bit - nobody can even notice the difference. And my story is the next: the Necronomicon is the most dangerous and demonic tome ever, and nobody can read from it out of a pentagram - I roll the empty pages to DEMONstrate :-) - and after draw a pentagram with chalk, perhaps light a magic candle, and roll the pages in this safety circle to show the written pages.Thanks for the idea! Fhtang!:-)

    View Instructable »
  • BigCthulhu commented on Dragwyr's instructable Magic Spell Book3 months ago
    Magic Spell Book

    Nice idea, I'll make this book. Thanks for it!Fhtang!

    View Instructable »
  • SIMPLE BUT PROFESSIONAL TELESCOPE FOR BEGINNER ASTRONOMERS

    Thanks for the serious and long comment. In my country the telescope maker Kulin Gyorgy, "the hungarian John Dobson" said that every student and the adults might look in a telescope at least once in their life, to see what Galileo has seen. He called this moment "Galileo-experience" - no serious observations, but a moment when the outsiders can see a small planet disk, some diffuse spots, and recognizing the naked eye star-like, or invisible objects with them (Jupiter, M13, M31, Orion-belt, etc.). With this concept people may turn towards the astronomy, as more other people turn towards the biology when look through a microscope lens observing the so interesting and weird small beings.My scope is for this "experience" - yes, the magnification is about the ...see more »Thanks for the serious and long comment. In my country the telescope maker Kulin Gyorgy, "the hungarian John Dobson" said that every student and the adults might look in a telescope at least once in their life, to see what Galileo has seen. He called this moment "Galileo-experience" - no serious observations, but a moment when the outsiders can see a small planet disk, some diffuse spots, and recognizing the naked eye star-like, or invisible objects with them (Jupiter, M13, M31, Orion-belt, etc.). With this concept people may turn towards the astronomy, as more other people turn towards the biology when look through a microscope lens observing the so interesting and weird small beings.My scope is for this "experience" - yes, the magnification is about the same, but the design - achromatic Kepler-system - is better - wide observing field, and - the most important benefit: no chromatic aberration, sharp and well balanced projection without noticable blue and orange edges around the objects.The contemporary scopes were made with poor optical lenses. A Galilean scope survived the centuries, but its main lens was broken - the examinations revealed its curves and the reconstructed image projection - and they found its optics poor. We may build a replica for some euros using cardboard and the replica lenses - these are normal simple glass lenses, like Galileo's ones - and can try the real Galileo-experience.[http://www.teleskop-austria.at/index.php?produkt=AM-232-HGT]I did, and I can claim its image is enough for the Galileo-experiance. Jovian moons, the disk of Jupiter, the Saturn and its rings - of course not really visible, but something at the disk edges, Mars, Venus phases, and some of easiest binaries... This is the Galileo-replica.By the way, as I remember, in Galileo's observer notes there is a sketch with a planet disk and two smaller disks at the sides of the main disk, and a cyphered note, which says: "I noticed the most outer planet as a three-elements system". This is Saturn, the last of the naked eye visible planets, and his small magnification and poor lenses projected it as a deformed, symmetric thing with "ears" at the edges. The observer couldn't recognize them as a an oval phenomena or ring,With my Kepler-system scope you can recognize the rings, but, to do this a very stable tripod is recommended. No move, no jump for the good observing. But this works only with the double lenses Ploessl eyepiece, with the simple eyepiece the magnification is insufficient for it.The Galilio-story is exaggerated a bit; he was punished not axactly for the theories he spreaded, but for a small but serious mistake: writting his dialogue-form essay about the theory, he personalized the dumb conversator, Simplicius (Simple Man) as the Pope. And, although they were friends and Galileo was a famous person, Vatican had to punish him - there wasn't torture, nor any serious terror, just a cancelling statement (and the ""Eppur si muove!", or "But it moves!" -legend is only the romantic part of the Galileo-legendary) and the house arrest. Other people would be executed for this sin - for example Giordano Bruno, who was burned by the catholicians. Galileo as a pensioner lived in the house arrest, there were friends and pupils around him, he was an old man in this time, and nobody wanted to kill him for his theories.You find Jupiter to be a bright white orb without any detail at all; perhaps one or two darker line is visible as a belt on the disk, when you can sharpen well with the eyepiece. And the moons (or satellits) of it is always visible even in a 4 cm diameter scope."Some amateur planet watchers construct very long focal length (low "f" number) reflectors to reduce the glare and increase magnification." - you say. Yes, but there is an other purpose of this design - with this long focal distance they could decrease the chromatic aberration of the simple lenses. This aberration I mentioned my issue is a very disturbing error of the simple lenses, that's why I always recommend the achromats for any scopes.Fhtang

    View Instructable »