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mikeDnight

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mikeDnight last won the day on March 17

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About mikeDnight

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  • Gender
    Male
  • Interests
    100% happy observing the Moon and planets, and 99% happy observing anything else.

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    Lancashire, UK

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  1. The cell will unscrew anticlockwise, but you may need to grip the cell and the tube tightly. Phone a friend with a strong grip to either hold the tube stationary while you turn the cell, or visa versa. It's best not to attempt to remove the lens itself from the cell if at all possible! I admit to being curious as to why you need to remove the lens, as it looks to be ok in the photo?
  2. In a Fraunhoffer it's usual for the front Crown element to be convex on both surfaces, while the rear Flint element has a concave surface facing forward while the rear facing surface looks almost Flat, though it isn't. If the flint is forward you may have spherical aberration.
  3. For anyone who's still waiting - I've got mine, and it's brilliant! 🤣 And its clear here with a first quarter Moon overhead!!!🤣
  4. A Newtonian will reach thermal stability significantly faster than a SCT, which is far more sensitive to internal heat because of the amplifying secondary mirror. But then a Mak Cass with a much thicker meniscus corrector would likely work at optimum before a SCT, so we come back to the schmidt plate being a problem. At the end of the day it comes down to personal preference, so for me I'd want a scope that performs as quickly as possible. I don't want to wait 2 to 3 hours before a scope gives its best. I'm impatient and as soon as the sky clears and I put an eyepiece in the focuser I want great views. If I were an imager I may feel differently, but as a purely visual UK observer, they are not for me. No other scope design gets such mixed bag of opinions.
  5. Over 45 years Ive only once seen a SCT give a great view of Jupiter and that was an old orange 1980's C8. Other than that, and no matter what the aperture, I've found them to be consistently disappointing as regards planetary sharpness. Schmidt's original design was to be used as a camera and that's where they seem to shine, though how much of that is down to stacking and computer jiggery pokery I've no idea! Maksutov's on the other hand, despite being similar in design other than the corrector plate, give very pleasing views, and once thermally stable, are probably as close to refractor like as it gets. So the issue with SCT's would appear to be down to the Schmidt corrector which is a thin mass produced lens made by sucking a optically flat plate onto a figured master plate. Once ground and polished it takes on the figure of the original. So the Schmidt plate is not an individually figured item, it's pot luck!
  6. I had an unexpectedly great night last night 15/3/24. The fritters drove past and shortly afterwards the clouds cleared. The Moon was well over in the west by this time and normally from my location the seeing is poor towards the west. This night was very different from the norm', as the atmosphere was as steady as I've ever seen it. I had an 18mm UFF & 10mm UFF to give a proper test run. I was using my FS128 and the Moon was breataking in both the 18 & 10mm. Intricate detail was easily seen as sharp as sharp gets in the floor of Theophilus even in the 18mm at 58X. The 100mm giving 104X was spectacular as its field encompassed the entire Moon with room to spare, but giving nothing up to the laser etched detail on show. This eyepiece in the FS128 would make a wonderful addition to any outreach eyepiece collection, but also will hold its own alongside any top end eyepiece costing considerably more. As the seeing was so amazing, I moved onto the SVBony 3-8 zoom to see how it performed with the Moon being at such a relatively low angle. It did not disappoint! At every focal length the 3-8 zoom gave sharp and comfortable views. I like the fact that I could fine tune the magnification by using the focal lengths between the click stops. Eventually the Moon dropped behind the tree line and so I changed target. Hercules was rising on his side in the north east, and looking through the scopes finder I saw M13 was looking good. Starting with the 30mm UFF the Starfield surrounding M13 was littered with tiny diamonds. Through the 18mm UFF M13 was a misty ball covered with a dusting of tiny stars. Even at this relatively low power, I could see variations in the placement of the globulars stars, giving the impression of uneven brightness and a dark lane cutting through the cluster slightly off centre. Then changing to the 10mm UFF the whole cluster came to life in almost 3D. I was observing from inside my observatory and from under a blackout hood so the only thing I could see was the starlit field through the eyepiece and the cluster of tiny stars set against a misty backdrop. It was gorgeous, and it had me looking forward to viewing M13 when its at an even more favourable angle. Again I had to try the 3-8 zoom and it delivered admirably, showing a sharp, contrasty view at every click stop. I'd only observed these two targets this evening but had spent about one and a half hours doing so. By this time I was pretty chilled as I'd been observing in my PJ's, and so called it a night. 😨
  7. Most definitely! I've seen a 120ED give significantly better lunar views than an excellent 200mm Dob; so much so in fact that the observers I was with were in disbelief at first. Then when both scopes were aimed at Saturn, the air turned blue with expletives, as they learned an important lesson - aperture isn't always King!
  8. Visual: 120ED Imaging planetary: C9.25 - though it would be a waste as I'd never image with it! It would make a potentially nice visual deep sky scope though!
  9. It's something to seriously consider! I've found that over the years, the bigger a scope is the less I want to use it. And the less impressive the view!! Big scopes very often leave me cold because I expect more of them, but the smaller ones nearly always deliver beyond expectation. I had a 10" F6 stood in my observatory for a couple of years, but it only occasionally saw starlight because I much prefered the comfort and quality of view through my 4". And years ago I had a Takahashi FS152 which is arguably one of the best refractors in the world, yet due to its size and weight, it lay in its case much of the time. The 152 Tak was an awesome scope, but setting it up, and worse still dismantling it when I was cold and tired, and the tube was caked in ice was off putting to me. I almost dropped it on one occasion after my back gave way during mounting. I'm not sure what would be more painful, my back or the £10,000.00 pile of broken Crystal in my quivering arms!? I'm of the firm opinion that you really can't beat a 4" refractor, unless you have a 5"!
  10. The FC's are terrific scopes, not only because they are optically excellent, but also because they are small and light. That means there's no excuses for not using them, and because of this you are likely to see great things through the Tak. The more you're at the eyepiece the more you'll see! They are not however magical, and are limited by their aperture as far as light grasp and resolution goes, but because of their top class objective, they are able to take magnification very well when seeing conditions permit. A 125mm however will have a noticeable jump in light grasp and will give very good views of solar system targets. Honestly, I think that either scope can be the scope of a lifetime, and both will give high quality views that will not fail to wow you. If your heart was set on the 125, then may be you'll kick yourself for not getting one?
  11. Its definitely a magic aperture for a refractor, and its as good as it gets optically, but it ain't no grab & go! 💪
  12. AstroSystems weren't the supplier when I desperately wanted an FL102. I'd saved the £2250.00 needed to buy the whole shebang, thinking I could buy off the shelf. Unfortunately TeleVue decided to import them into the USA, draining the supply to the UK. Some things are unforgivable and I'm never forgiving Televue! I'd saved the money in three months. Amazing what determination can do!
  13. You can get a 120mm and 130mm Tak. The 130 is a bit of a monster and needs a monster mount to carry it well, but the 120 is just about right for a portable refractor. You definitely need one! The TOA 130 at AstroFest 2007. The True Technology stand. (You'd struggle to smuggle one of these past the wife!)
  14. The one that I really wanted but couldn't buy new because of the appalling and corrupt practices of the then sole UK importer at the time, was the Vixen FL102 with all the trimmings - motorised EQ, set of LV eyepieces, the job lot! If I'd have been able to get that scope I'm convinced I'd never have looked at anything else. It would have been my dream scope for life. I'd be wearing a "Who's Takahashi"? baseball cap permanently? ( For clarity, Baseball is the girls game of Rounders to us Brit's).
  15. Strangely, I've never even thought about looking for it, but I'll certainly add it to my fishing list. Thanks! 🙂 I love prompts like this. The last one, a few years ago, was Whos Seen the Horse Head? or something like that. It got me wondering if I could glimpsed it in my 100mm, and to date it was the single most difficult thing I've gone for and succeeded, though it looked like a dark notch and nothing like a horses head.
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