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Putaendo Patrick

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About Putaendo Patrick

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  1. Putaendo Patrick

    which telescope to choose?

    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. Putaendo Patrick

    6 inch Refractor- recommendation/suggestions

    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. Putaendo Patrick

    Which first binoculars

    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. Putaendo Patrick

    Classic "volcano top" orthos in demand ?

    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. Putaendo Patrick

    Quadrilateral Earth & convex sky dome

    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. Putaendo Patrick

    Show us your space stuff

    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. Putaendo Patrick

    Show us your space stuff

    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. Putaendo Patrick

    Which telescope to buy.

    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.
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