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About rl

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    Star Forming

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    pershore, worcestershire, uk
  1. It should be absolutely be fine if the collimation is ok. You will need to wait for the scope to cool down before trying any close doubles (closer than 2-3 arcsec) and need steady seeing. Wide doubles, any scope will do The weapon of choice for close doubles is generally considered to be a long focus refractor, for reason of their contrasty diffraction patterns, but I've used all sorts successfully over the years, including short focus Nertonians. The main thing is that the optical quality needs to be good, and the seeing good enough to allow full use of the scope's resolution. Refractors really come into their own on doubles that are very unequal but your scope should not be too far behind.
  2. An excellent result...I'd quit while you're ahead! More seriously, like a lot of things in astronomy, a law of diminishing returns sets in looking at the improvement you get for extra time, cost and effort. And your standards go up with more experience which only adds to the sense of frustration...
  3. If you want tickets for the lectures then book now....they're always sold out on the day. You can still get in to the exhibition.
  4. Hmmmmm...and Astrofest coming up! Can I resist two years running?
  5. Providing the quality of the big lens at the front ( called the objective) is ok, you will see Jupiter and its moons with what you've got. Also the rings of Saturn, lots of craters on the moon. Now, to manage expectations, take a dime and hold it at arm's length. That's a bit bigger than the size of Jupiter in the scope, but you can still read the writing. That's the sort of image scale to expect. Saturn is half the size again..... You can detect a lot of galaxies and deep sky objects from a non-light-polluted sky with what you've got. Note the word "detect"....most of them will look like faint fuzzy patches of cotton wool. You have to learn to spot the detail with averted vision and a lot of patience...but half the thrill is in understanding what you're looking at rather than the brilliance of the view. As for cameras, all you can really do with what you've got is take pictures of the moon. There are adapters available to suit most SLR cameras (but Canon is the astronomer's favourite). To take pictures properly you need a telescope that tracks the stars with a driven mount (equatorial mount). The optics need to be a step up on what you've got for general good results. You need to do some reading on this....but a fast apochromatic refractor will be good for wide field shots of deep sky objects. For planets...bigger is better scopewise and you will need a different camera....modified webcams are popular or their better astro cousins. The idea is to take a lot of frames and then select the best. Then add them up so the details comes out better........ If you're going the astgrophotography route then welcome to a difficult, expensive, frustrating and occasionally very rewarding hobby with a phenomenal learning curve.....the standard recommendation is a book "Making Every Photon Count" By Steve Someone whose name escapes me at the moment. Don't rush into buying kit....take some time reading first. It's just not possible in a single reply to go through all the options. And people would need to know more about your likes and circumstances before giving useful advice. Welcome to the forum, RL
  6. Very nice set of images taken in rather poor seeing. I've seen sharper at that scale but not too often. Just goes to show why the 6" Newt has been such an institution even if it's rather overlooked nowadays simply because they're cheap. In the right hands they are still a formidable observing tool. Nice presentation too..well done!
  7. Nice to hear of a Meade LX with mechanicals lasting so long since the milennium bug was a relevant issue...
  8. The ES17/92 weighs more than a kilogram. Will the scope plus 45 degree diagonal support it without balance problems? It's a great eyepiece on big scopes but can be an embarrassment on small ones.
  9. A few years ago I was mulling over exactly the same arguments. F/5 too short optically, F/8 too long OO-UK made me a VX 6" f/6 specially to order with a 1/10 ultra grade mirror and small secondary. It's very light, easily portable, with stonking optics that really deliver given the usual Newtonian caveats. You can get away without a coma corrector with a lot of eyepieces. It will handle *200 on moon/ planets given a good night with ease.
  10. The ZAOs were made, I believe, about 25 years ago. Unless we’re to settle for vague romanticised explanations about ‘the lens maker’s art’ and the like, their objective qualities are presumably analysable and quantifiable. What’s stopping equal quality from being produced and on offer now? I suspect this comment from above contains more than a grain of truth. I've never looked through a ZAO ortho which probably rightly disqualifies my opinion, but I have had professionally assessed several newtonian mirrors made by famous names of yore. In fact I've got a shedful of them... the results are never bad, but are often very average by today's production standards. But somehow the myths linger on. In this case the real and considerable achievement of the old manufacturers was to get good results with simple test equipment without letting any lemons through. But time, and production techniques, move on. I've no doubt Zeiss were/ are extremely good indeed, but others will see the example and copy, and innovate in turn. Maybe the real question lies in the words analysable and quantifiable. Is it possible to design an objective and repeatable test, say by eyepiece projection on to a CCD camera from a standard image, that will allow scatter and contrast to be compared? There is a similar thing (MTF = modulation transfer function) for camera lenses.
  11. I do wonder whether designers ray-trace their designs for a wide range of eyeball prescriptions. Maybe the acceptable range should be in the spec.
  12. Thanks John.. My comment was directed more to Louis' point about the field stop being in focus. The field stop is generally set up to be sharp for an eye looking to infinity...for a short-sighted person such as myself the correct position would be further in towards the eye...hence I see the dust in-focus and the field stop slightly blurred. But eyepieces like the Ethos, Delos, ES17/92, all seem to have a sharp field stop regardless! Maybe it's something to do with the Smyth lens. Or a little piece of magic from Unk Al. The view in a few eyepieces completely falls apart when used with uncorrected vision...ES25/100 is by far the worst example in my experience But we're going off topic....apologies
  13. Yes, but I guess I'm used to that.... Strangely enough not all eyepieces do that. Don't know why. RL
  14. I had the 40mm XW from new for some years, used it with a 14" f/6 dob and a paracorr. It was seriously brilliant viewing for the Virgo cluster and other deep sky stuff. In the end I sold it for financial reasons for what I paid for it....a few months later s/h prices went through the roof after they were dropped from the range. One minor minus...I have short sight and this meant the eyepiece worked with the focal plane almost on the front surface of the field lens...any dust particles were all too obvious if it was used on the moon, as occasionally happened with a f/15 scope. A total non-issue on deep-sky though..or if I used specs. I'd buy another for the US prices quoted above.. RL
  15. Hmmmm, I recognise my kitchen in those photos!
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