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Putaendo Patrick

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Everything posted by Putaendo Patrick

  1. Buying a decent telescope in Egypt by all accounts is not easy and not simple! In fact, I believe private ownership of a telescope was illegal in Egypt until a few years ago. If you live in or near Cairo, I think there's an astronomy society at the American University so perhaps one of the members can give you some good local advice. I've never used or seen the Voyager telescopes, but to me a 150mm refractor for 520 or 720 dollars (depending on focal length) seems worryingly cheap given that I would expect prices to be much higher than Europe or the USA. I would certainly try to find someone who has one and ask their opinion, or even ask them to let you try it! The Voyager price list does however offer the Celestron 8" SCT and although it's considerably more expensive, it is a known brand with a very good history and a loyal following for this particular model. At the end of the day it might be the better option if you can find the money! I wouldn't compare an 80mm refractor to a 150mm reflector - but as a rough rule, I might compare a 120/130mm refractor to a 150mm reflector, or a 150 to a 200. BUT other factors will come into play such as lens and mirror quality. Chromatic aberration (CA) or fringing is a problem especially with faster achromatic refractors, however it will be less present with longer focal length. 1200mm will give less noticeable CA than 750mm. I don't know how old you are, but the good news is at CA becomes less of a problem as our eyes age.
  2. A lot depends what you want to spend. Prices can range from about 25 pounds for a basic but reasonable quality Plossl to several hundred for a top of the range EP! In addition to the magnification that an EP will give, it's worth considering two other factors: field of view and eye relief. Field of view, measured in degrees, is how wide you can see while eye relief is how close your eyeball needs to be to the EP glass. Many people find extended viewing with their eye very close to the EP can become uncomfortable. Plossls are an excellent EP design but higher magnification versions (with a focal length number lower than 8 or 10 mm) suffer from poor eye relief and also have a narrow field of view. Orthoscopic EPs such as the Baader Classic are also very good indeed but again have the same problems as Plossls. An additional advantage of using a Barlow is that it will keep the original eye-relief of the EP - thus you will get better eye relief using a Plossl 10mm with a x2 Barlow than using a 5mm Plossl on its own. Beware however, a poor Barlow with a poor EP will only double up poor viewing. Celestron Omni, Revelation and Antares all make very acceptable Barlows at about 30-40 pounds. The BST Explorer or Starguider (both are brands of the same EP, along with Paradigm and one or two other names!) is a step up with both better field of view and eye relief - and although a little more expensive, it is still an excellent value entry level eyepiece.
  3. I think the new Altair has a 3" focuser versus Telescope House's 2.5 inch, but otherwise they are pretty similar. so much so that I'm tempted to think the TS version is a rebrand and the optics may in fact be the same.
  4. The larger the aperture of your telescope, the better you can view fainter objects and obtain good resolution at higher magnifications. However there is hours and hours of fun to be had with a smaller telescope, especially when you're starting out. Reflector telescopes which use mirrors are generally cheaper to manufacture than refractors which use lenses - so they are perhaps better value in terms of price/size. Dobsonian mounts also represent very good value. But again, they don't suit everyone's needs. How are you planning to get to Sark? Travelling by air will limit your size and weight, but there are various possibilities. A budget of up to 500 pounds will give several options, including a rich field refractor which would be excellent for wider views at lesser magnifications, or a Maksutov which combines mirrors and lenses which might be better for higher magnification but will give narrower views. Both of these could be used on a reasonably good photographic tripod with an adapter. https://www.firstlightoptics.com/maksutov/skywatcher-skymax-102-ota.html https://www.firstlightoptics.com/startravel/skywatcher-startravel-102t-ota.html Both of these have apertures of 102mm, but there are smaller versions with 80mm which are also very popular as portable telescopes.
  5. You can spend 400 pounds or more on one eyepiece, but you can also pick up a very reasonable EP for about 25 pounds! Two of the reasons that justify this difference in price are optical quality and design, and these influence factors such as field of view, eye relief and image quality in fast scopes. Field of view can range from about 50° in an inexpensive Plossl design to 100° or more, and basically means you can see more. Eye relief is how close your eyeball needs to be to the glass - if your eyeball has to be very close, this can be uncomfortable for extended viewing (and if you need to wear glasses, is just impossible). Most eyepieces should give sharp views in the centre, however many begin to deteriorate significantly as you move out towards the edge of the view. This problem is particularly noticeable in "fast" telescopes. Divide the focal length of your telescope by the aperture (in your case 650mm by 130mm) to get a number known as the focal ratio. F6 is average, a telescope with a lower number (yours is f5) is considered fast, while a higher number is slow. Some eyepieces just won't work well in fast scopes. Collecting EPs can become obsessive, and I warn you there is no known cure . But to start with I would aim to build up a basic range of no more thanthree with low, medium and higher magnifications. Personally I might go for 20mm which would give x32.5 (although you might also look for a second-hand 25mm, these often come supplied with telescopes and are sold off as people upgrade) and a 5mm which would give x130 - great for planets and detail on the Moon. And finally something in between, perhaps an 8mm giving about x80. If you find you are attracted to observing the planets, you might eventually want more magnification - but remember higher power only works with the best atmospheric conditions and in the UK that can be quite rare. Another useful optical tool to increase your range of magnifications is the Barlow. This effectively increases the magnification of an EP by a factor - typically x2 although other factors are possible. Thus, for example, a 20mm EP with a x2 Barlow will perform as a 10mm, giving x65 magnification. An additional advantage is that it will maintain the eye relief of the original EP (higher magnification Plossls for example can have very tight eye relief). Beware of buying very cheap Barlows - combining a poor optical quaity Barlow with a so-so EP will just double up your problems - Ouch! If you stagger the magnifications of your EPs carefully, this can be a very economical option. One further possibility is buying a zoom eyepiece. These usually come in 8-24mm (avoid 7-21mm - for some reason these don't work well) although they perform best in the 10mm to 20mm range. Unless you spend a lot of money, these type of EPs are always something of a compromise - but at 60-70 pounds, there are examples which are quite acceptable and will allow you to determine your most used magnifications. Just a few of the available options you might consider are: Celestron Omni Plossls, about 25 pounds each. Although not the best, good value for the price. Vixen NPL Plossls, about 40-45 pounds. Very good quality. Limited field of view, and tight eye relief on higher magnifications. BSL Explorers (also marketed as Starguiders, Paradigms etc). Very popular here on the SGL forums - about 50 pounds. Explore Scientific 68° and 82° series - now about 115 pounds. Probably the next big step up before hitting painful money! Great performers. Baader Classic Orthos are also very good especially for planetary observing, although eye relief is limited. Nicely flat viewing with minimum distortion for the price - about 50 pounds. Also well worth keeping an eye out for second-hand. Most astronomers keep their EPs in very good condition and savings can be significant!
  6. Looks like you could save a fiver and buy the same in green: http://www.uttings.co.uk/p123743-opticron-adventurer-wp-10x50-dcf-ga-binoculars-green-30067/#.WN-yg1Uw601
  7. A few years ago Orthos almost disappeared from the market altogether. Baader stopped their Genuine line and Circle T (whoever he was) apparently went into retirement. Since then they've made a well-deserved recovery. Baader have now reintroduced the Chinese-made Classics and Fujiyama seem to be supplying a niche demand - basically because these are great EPs without breaking the bank. Baader Classics are now nearly 50 pounds each and Fujiyamas about 80-90 pounds each - and Circle Ts will give both a very close run, some might say better! So while increasing prices may be caused in part by fashion, I feel they're well within bounds and still well worth it .
  8. I rather like this world view from a certain Professor Orlando Ferguson, mid 19th century I guess: Christine Garwood wrote an enjoyable book in 2012 entitled Flat Earth, the History of an Infamous Idea. Although particularly strong on the 19th century religion versus science debate, it has a good overview of many theories prevalent at different periods of history.
  9. As I understand it, in this case the new focuser is significantly shorter so he's adding another component between the OTA and the focuser which is essentially a 3.75" extension tube. Technically I guess this is not part of the focuser, but at the same time it could be considered part and parcel of the overall focusing set-up. If you choose to upgrade, this may or may not be necessary depending on which replacement focuser you go for - I think .
  10. One piece of kit I find is a great compliment to a telescope is a pair of regular 8x40 or 10x50 binoculars - not rubbish but not expensive either, about 50 pounds new gets you some good options.
  11. I don't know if this is actually true, but I've often heard that Japanese astronomers preferred not to use diagonals with refractor telescopes - I'm guessing these would be amateur telescopes from the 1960s and 70s. So perhaps it's just a question of getting accustomed - but my neck pretty well insists on a diagonal! In general, most diagonals which come with Maks are acceptable for most purposes (although a decent dialectic may be an improvement), so if PatrickO is finding the viewing is seriously degraded, there may be a problem, for example with mirror alignment?
  12. Wow - thanks, Moriniboy. My very own Russian nightclub on my wrist - I just feel that after a couple of bottles of Stolichnaya, all that neon might make my head hurt! Actually I was thinking maybe Belka and Strelka - the first dogs who went to space and CAME BACK! (I've never quite forgiven the Russians for Laika). Or perhaps, more human, Gagarin and Tereshkova:
  13. Very nice indeed! I've been scouring ebay for a space themed Soviet/Russian watch but so far haven't found quite what I want
  14. Reflector telescopes do need periodic collimation - fine-tuning the alignment of the primary and secondary mirrors. First time it can be quite a nerve racking experience - but with practice, it really is a simple operation! You will probably want to buy a Cheshire eyepiece to do this, cost about 40 euros. In terms of observing capability, there really isn't much difference between a 6" refractor and an 8" reflector. I think I'd prefer a refractor for planets and a reflector for DSOs - but honestly I'm not at all sure . Quite a bit of your budget is going on the tripod mount with both options. For visual observing, you might also consider a Dobsonian reflector, for example https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-dobsonian.html
  15. The Skywatcher 130/900 is a good enough telescope for basic visual observation. It is, however, an older design which will not be ideal for astrophotography. If you want to get into imaging, take a look at 130P-DS http://www.skywatcher-india.com/Product/ProductSpecFeature/101 This model has a parabolic mirror and an improved focusing system which allows for better fine focusing and also allows you to reach focus with a camera. It is also a "faster" telescope (f5 versus f7.9) which is generally preferred for photography. Many members of this Forum have used it with great success for astrophotography, and it also performs well visually for a 130mm reflector. For visual observation, however, larger aperture will give better results - more definition will allow you to see fainter objects and obtain higher magnification when necessary. In this case 150mm will out-perform 130mm. For imaging, however, there is an improved model which would be well worth considering http://www.skywatcher-india.com/Product/ProductSpecFeature/102 A good mount is very important, and others have said, the EQ2 is not really up to it for the 150mm tube. When you go into astrophotography you will need a considerably better mount, either with motors or computerised go-to tracking. The EQ3 would work well with the 130P-DS, http://www.skywatcher-india.com/Product/ProductSpecFeature/271 (cheaper without the gps), but for a larger tube, however, something more solid would be better - the HEQ5 would be a good choice. And this starts becoming expensive - especially outside Europe or North America, where import costs and mark-up can be very high! Still, this may give you an idea of where you need to be heading.
  16. Be aware that the 102 and the 130 are different types of telescope, each with their strengths and weaknesses. The 102 is a Maksutov design which combines mirrors and lenses, and has an effective focal length of about double the 130 which is a reflector telescope with a focal length of 650mm. In practical terms this means the 102 will work best at higher magnifications but with a much smaller field of view, it would be excellent for example for lunar and planetary observing. The 130 will perform better at lower magnifications with a considerably wider field of view, so very useful for DSOs Both telescopes have relatively narrow apertures - the bigger the aperture the better you can resolve faint objects. Personally I'd recommend something a little larger, such as this with an aperture of 150mm https://www.firstlightoptics.com/reflectors/sky-watcher-star-discovery-150p.html Probably not as compatible with your aps and gadgets, but I think an all round better telescope. Don't know if it's available yet in the USA but Skywatcher are increasing their presence in the market so it might be worth asking around.
  17. Personally I'd go with a better telescope rather than goto if the budget is limited. While goto can make finding targets much easier, learning to find them manually will teach you a whole lot more. Download the Stellarium program for your computer, maybe get a star map ap for your phone, and buy the book Turn Left at Orion and you should be ready to go! I have the Celestron 120 Omni and I'm very happy with it. You might also look at Skywatcher and Bresser who do very similar models. Yes, there are better refractors but at a whole different price level! The supplied CG4 equatorial mount is good enough, and you will soon get used to it. For visual observing, you don't need to set it up very precisely. Be aware, though, that the 120 is a relatively large telescope - I'm not certain that any of the less expensive alt-az mounts would support it. EQ mounts do take a bit of practice at the beginning, lbut you'll soon get used to it.
  18. Both will give quite high magnifications. The 5mm will provide x240 with your scope - this can be useful for the Moon, but in general it is right at the limit of what you can expect with very good atmospheric conditions, and there will probably be many nights when you can't use it. The 7mm will give about x170 and will be much more useful in many situations. Check that these are the XL model - if it's the earlier series without the XL written on the eyepiece, most people really really hate these, not one of Celestron's better designs! The XL series, however, are good and new price is about 65-70 pounds each.
  19. Must be getting late! I thought I was replying to another post completely Thanks Faulksy.
  20. A lot depends on conditions, as you say, and the position of the planet. I generally get best results between x120 and x180 magnifications. In your telescope with a focal length of 1200mm, these extremes would be 10mm and about 6.5mm. The choice of eyepiece depends in part on money, but also on design. A Plossl at 10mm will have a comfortable eye relief at 10mm, less so at 6.5mm. I also like orthoscopic eyepieces, but again the eye relief is limited. BST Starguiders or Paradigms (same EP under different branding) are also excellent mid-priced eyepieces with good eye relief. Personally I don't like wide field of view EPs for planetary observing, I find it distracting - although with a Dobsonian mount, your target will say visible for longer between nudges of the scope.
  21. There's a long thread with some really, really spectacular images taken using the 130pds: Well worth spending a bit of time working through it! But, in addition to the telescope, look at the other equipment being used - mounts, guide scopes etc. My last suggestion, a Dobsonian 200mm, is excellent for visual but not suitable for anything but the most basic imaging
  22. To an extent visual and imaging create a conflict for the ideal telescope. For visual observing, the bigger the aperture (diameter of the tube) the better. This will give more resolution for fainter objects and allow more magnification when needed. For imaging aperture is not so important, and the weight and size of a larger telescope will mean a larger mount which can get very expensive. So, depending on your economics, some of your choices might be: A telescope suitable for imaging, but used for the moment with a manual mount for visual. https://www.firstlightoptics.com/reflectors/skywatcher-explorer-150p-ds-eq3-2-eq3-pro-goto.html A telescope with computerised go-to right from the start. https://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-eq3-pro-goto.html A manual telescope good for visual for now, with a second telescope for imaging later. https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-200p-dobsonian.html
  23. A very nice telescope! Congratulations. By the looks of it, it should clean up very nicely. There's a complete one on ebay http://www.ebay.co.uk/itm/Astro-Astronomical-Refractor-Telescope-F-1250-Front-Lens-Dia-76-2-Kit-Box-Used/332103874620?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D41433%26meid%3D2f992a82a74340bd986faa197e8f362f%26pid%3D100011%26rk%3D1%26rkt%3D1%26sd%3D262184986699 buy it now for nearly 200 quid - expensive, perhaps, but another similar did sell for 149 pounds a while back. Circle K may have been made by Kenko - these small marks were put on most Japanese telescopes I suspect to identify them for a state quality control institute. If it's Prinz, this was a brand of telescopes and photographic equipment imported and sold by Dixons, in it's day a mayor high street chain of electrical goods - although if so, I'm surprised it is not specifically branded as Prinz. In the USA similar telescopes were imported by Tasco, K-Mart, Bushnell etc. John Diebel, the founder of Meade, in fact started by importing these type of telescopes from Japan which he sold by mail-order. I suspect your telescope was made in the late 1960s, perhaps early 1970s. There's some variation in quality, but the good ones are optically superb and, relative to todays prices, were quite expensive!
  24. I guess this story could be just imaging, but I think maybe a wider public will be interested. Former JPL Engineer Honored for 'Camera on a Chip' If you're reading this on a smartphone, odds are its camera uses digital imaging technology developed at NASA's Jet Propulsion Laboratory in Pasadena, California, in the 1990s. Eric Fossum, who led the team that created the breakthrough "camera on a chip" at JPL, is one of four winners of the world's most prestigious engineering prize, the Queen Elizabeth Prize. The award celebrates world-changing innovations in engineering with a prize worth about $1.2 million. This year, Fossum and three other engineers are being honored for creating digital imaging sensors, which have revolutionized the way we capture and analyze visual information. In the early 1990s, Fossum and his team at JPL created the complementary metal oxide semiconductor (CMOS) image sensor -- also known as "camera on a chip." The breakthrough technology, referred to as an image sensor chip, came about while Fossum and his team were trying to drastically reduce the size and power needed for cameras on interplanetary spacecraft, without sacrificing image quality. They invented the CMOS active-pixel sensor (CMOS-APS), which required just 1 percent of the power needed by the previous technology, charge-coupled devices (CCDs). They realized this technology would be useful not only in space but also here on Earth. This breakthrough revolutionized digital cameras, and the sensors are now ubiquitous -- in cameras and smartphones, for example. Fossum led the sensor's technology transfer to U.S. industry. In 1995, he founded Photobit, a JPL spin-off company, to commercialize the technology. Fossum is currently a professor of engineering at the Thayer School of Engineering at Dartmouth College in Hanover, New Hampshire. Other winners include George Smith for his work on the CCD, while at Bell Laboratories; Nobukazu Teranishi for his work on photon counting image sensors for visible light X-ray at NEC Corporation; and Michael Tompsett for his inventions related to CCD technology, also while at Bell Labs. The Queen Elizabeth Prize for Engineering is a global prize that celebrates a ground-breaking innovation in engineering. It rewards an individual or team of engineers whose work has had a major impact on humanity. Full story, photo and links at http://www.jpl.nasa.gov/news/news.php?feature=6735
  25. Generally you should have no problem achieving higher magnifications on the Moon than on other targets. On a good night, I can often push magnification up to about x260 with a 120mm aperture refractor, and the detail is incredible.
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