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Ben the Ignorant

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Everything posted by Ben the Ignorant

  1. You should have said that to all who mentioned other eyepieces more than 40 times in this thread, and to yourself, 13 times. Same for you.
  2. The Explore 24mm/68° and the maxvision 18mm/82° have the same true field as the Tele Vue 32mm/50° or the 40mm/43° but with a more panoramic view and more magnification. Both have a maximal diameter field lens: (and cleaner lenses inside the Explore but they rest on a powerful torch so the slightest particle looks enormous) And what about eye relief? Do the pupil on paper test and you can compare with your own. This is a ceiling tube lamp so the pupil looks like a line but the pupil on paper test is valid as long as the pupil is focused sharp on the p
  3. And recoil even more looking through a window but it can be better, and I have photos to prove it.
  4. What should I be able to see? is the most natural question, and it would be very easy to answer if there were no light pollution, and no personal differences between observers, but these factors are too variable. So the answer is look at everything, starting from the brightest things, and build up your own experience. Light pollution maps are not nearly detailed enough; you might live in a theoretically very bad Bortle zone and have real life decent skies if your site is shielded by walls and trees. The closest lamps are the worst enemies, and just having no direct light in your spot m
  5. Yes, this used to be the case but not anymore with recently manufactured windows: To answer your question, Sphenoid, several good scopes can be had for 200£ (230€). The latest nice offers are I've seen are: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p802_Skywatcher-Evostar-90-auf-EQ-2-Refraktor-Teleskop-mit-kompletter-Ausstattung.html https://www.bresser.de/Astronomie/Teleskope/BRESSER-Messier-5-Dobson.html https://www.teleskop-express.de/shop/product_info.php/info/p2705_Skywatcher-Heritage-130P-FlexTube-Dobson---6years--.html https://www.t
  6. An ED lens gives optical designers a large advantage, especially with FPL-53 and FPL-55 glass but these are very costly, and the two other lenses matter immensely. I think they have a choice between twenty or thirty glass types, so if a triplet can be great with lenses of less radical properties but lesser cost, they should go that road. It's probably what they did here, the two ED elements have got to be the more affordable type. Straight Ronchi lines and a white star test are all that matter in a triplet apo, anyway, what glasses do it doesn't count a bit. By the way, it's a shame all t
  7. (speaking of TEC's 140mm f/7 triplet) Well, those who say that should know the facts can be found on the internet to prove them wrong. Rohr tested it and found less than 70µ chromatic spread: A Vixen 130SS I looked through has 150µ chromatic spread and no fringe could be detected at all around the Moon, Jupiter and Mars. The W_gesamt 0.9381 value means the scope is an apo because it's under 1. Between 1 and 2 are the semi-apos, and achros are above 2.
  8. They have an official rep in the US now. https://www.outdoorsportoptics.com/shop/telescopes_pw1_6_1.html
  9. Apo binocs with FPL-51 or equivalent glass are nothing new but this one has an air-spaced objective that should be better corrected. Also, the long extensions are not dewshields, they are part of the optical tube so the objectives are far away from the eyepieces, allowing for a longer focal length and another gain in correction. https://www.teleskop-express.de/shop/product_info.php/info/p11809_William-Optics-22x70-ED-APO-Astro-Fernglas.html Too expensive and long and heavy for me, I'm dreaming of the shorter and more affordable APM 16x70 but good to know what everybody makes.
  10. TS asked Sharpstar to make a shortish 140mm triplet (to compete with TEC's 140mm f/7 triplet apparently), and the result is presented in their website today. To keep the stars tight over a large field at the kinda steep for the diameter f/6.5 ratio, they put two low-dispersion lenses in the objective (Takahashi does the same in some large apos). The focuser is a very large 4" unit, and the scope can operate at f/4.8 with a 3" reducer, imagers will love that. https://www.teleskop-express.de/shop/product_info.php/info/p11814_TS-Optics-140-mm-f-6-5-Super-Triplet-Apo-mit-2-ED-Elementen.html
  11. Sky&Telescope's Pocket Star Atlas (20€) if you need compact paper star charts.
  12. Hello, Armando. You must be very experienced after sixty years.
  13. My red and white torches had uneven light... ...but simply rubbing the lens or the red filter with a kitchen sponge made them so: About 25cm away from my APM binoc's white box, would look the same on a star map. The gradients are because the camera does not have enough nuances, visually the spot is totally blended. It took an awful lot of time with the white torch because its lens is a high quality plastic, had to unscrew it, too. It used to project a very detailed and very annoying image of its yellow LED emitter but now its glow is as smooth as can be
  14. You don't have to sacrifice aperture to get a more portable scope, the question of portability has been asked by users and tackled by manufacturers, and they came up with 150mm tabletop dobsonians. The most affordable is the Bresser 150 f/5. https://www.teleskop-spezialisten.de/shop/Teleskope/Dobson/bis-150mm/Bresser-Messier-6-Dobson-Newton-Reise-Teleskop-mit-Zubehoer::3462.html It costs about 40€ more than the Sky-Watcher but it has a vastly wider field of view, and it's much shorter and lighter. And for the sake of being complete, Bresser also makes a 130mm f/5 tabletop, but t
  15. You need to assess your local turbulence before you spend money and get more gear to store and handle. Make a 150mm off-axis mask for your 400, its reaction to turbulence will be similar to that of a 180mm scope. The obstruction and larger diameter of the 180mm will make it a bit more sensitive to air motion but the off-axis mask costs no money and yields some good info. Also, as others have said, the powers at which your dobs break down seem kinda low so your scopes probably need a little refining of the collimation.
  16. I bought the product so long ago, I'm not even sure that business is still around, but Car Lack 68 gives the tube's paint such great polish, the rings and tube get the right balance between stickiness and smoothness. It works on my brother's 150mm Celestron and my 130mm Sky-Watcher, which seem to have the same black color with an orange peel texture paint job.
  17. That's not normal, maybe the felt Inside the rings is too thick, or they are nor perfectly round.
  18. Another suggestion is this: A couple strong O-rings on each side keep the mounting rings tight enough but the scope can be rotated or slid up and down to keep it balanced when you change between eyepieces of a very different weight. The screws are completely loose except when I carry the scope, their main job is only to keep the O-rings from sliding out. A few rubber bands do the same trick but they don't look techie like black O-rings do.
  19. Hello, Andrea, you'll probably appreciate these resources: http://www.dark-star.it/ http://www.astrotest.it/ https://www.telescopedoctor.com/ http://www.davidesigillo.eu/index2.html http://www.binomania.it/
  20. The Moon is a sunlit rock, so if it is blindingly bright any sunlit lanscape is blinding, too, and needs to be viewed through filters. But I've never seen anyone being dazzled by a sunlit landscape in a large scope, and we used our club's 400mm newtonian on landscapes a few times.
  21. If your lifetime telescope is that Inspire 80, yes. But if you upgrade later a basic narrow-field eyepiece like that 32 will restrict what you can do with your scope. So learn with what you have, and wait before you spend.
  22. I've done that job with success so this might help: But by all means, NEVER dump a telescope, give it to someone who is willing to try to salvage it. Welcome, by the way, and happy cleaning chore!
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