tripod tipper Posted July 25, 2016 Share Posted July 25, 2016 Hi all, I've just re entered the astronomy hobby. I have a Celestron PowerSeeker 80EQ refractor with a motor drive. It has great clarity but the eye pieces have plastic lenses, I would like to go with coated glass lenses and filters. When I bought the 80EQ it came with a 20mm, a 4mm and a 3X barlow. I would prefer a 2X barlow and a better range of eye pieces. I do understand the magnification formulas. Could anyone direct me to a reasonable source for a kit, I have to restrict myself from buying the best and overstocking myself with more than I need, (a personal challenge). Link to comment Share on other sites More sharing options...
Timebandit Posted July 25, 2016 Share Posted July 25, 2016 Hello and welcome to SGL. The BST seem to have a good following on here and good performance. Good field of view and a sharp performer, so well worth a look. I think they are around the £50 mark. I hope this helps☺ Link to comment Share on other sites More sharing options...
Putaendo Patrick Posted July 25, 2016 Share Posted July 25, 2016 Upgrading your EPs will be an enormous improvement. Generally the rough maximum magnification you can expect from a telescope is double the aperture in millimeters, in your case about x160. Much above this and the quality of viewing will defeat further magnification. So really a 5.5mm eyepiece is probably the top. EPs vary in price from about $20 up to nearly $1000 for really premium glass, so an idea of your budget would be useful. This difference in price is largely due to the complexity of design as well as the quality of polishing, coating etc. Plossl EPs are very good value at the lower end of the market, with a wide range available at about $30 upwards, however they tend to have quite short eye relief especially at higher magnifications. The Vixen NPL series is excellent for the price: http://www.vixenoptics.com/Vixen-Telescope-eyepieces-s/115.htm Although again with short eye relief, othographic EPs are very good for higher magnifications, for example the Baader Classic Orthos: http://agenaastro.com/baader-classic-ortho-eyepiece-6mm-2954106.html Another type of design is the Paradigm (also sold in Europe as the BST Explorer or Starguider etc.) which gives much more comfortable eye relief: https://www.astronomytechnologies.com/astro-tech-paradigm-dual-ed-eyepieces_c17.aspx The Antares x2 Barlows are very good for the price: http://agenaastro.com/antares-1-25-2x-barlow-lens-twist-lock-adapter-t-thread-ub2stl.html For reference, this gives you a basic idea of some different EP designs: Link to comment Share on other sites More sharing options...
beka Posted July 26, 2016 Share Posted July 26, 2016 Hi tripod tipper, if you are new to the hobby I would not go for expensive glass. I used the eyepieces in the Celestron 1.25 inch eyepiece and filter kit for a long time with my first telescope (Firstscope 114 f8 reflector) and also my CPC 1100. If you don't wear glasses you will be able to see a lot with these while you refine your observing skills and determine the kinds of objects (planets, deepsky etc.) you are more interested in. You will be in a much better position to determine which accessories (or scope) you may want after some months or longer of observing. Link to comment Share on other sites More sharing options...
tripod tipper Posted July 26, 2016 Author Share Posted July 26, 2016 Thanks beka, Thank you for the response. I do wear glasses. I have always had reflectors, this time I bought an 80EQ from Celestron. it's been a long while since I've been in astronomy. The eyepieces I got with the kit only had a 3X barlow, a 20mm and a 4mm, no filters. I found them to be plastic lenses, I did purchase coated midrange eyepieces to widen the usefulness, a 15mm, a 9mm, a 6mm, a 5.5mm to add to it. I also purchased filters that didn't come with the scope, a 15 deep yellow, 58 green, an 80A blue, an oxygen-III nebula and a moon filter. I figure if I do go bigger, I will have what I need. I did spend more than I would have aloud myself (please don't tell my wife), however I now can re familiarize myself with the ranges of observation. Thanks again Link to comment Share on other sites More sharing options...
beka Posted July 27, 2016 Share Posted July 27, 2016 16 hours ago, tripod tipper said: Thanks beka, Thank you for the response. I do wear glasses. I have always had reflectors, this time I bought an 80EQ from Celestron. it's been a long while since I've been in astronomy. The eyepieces I got with the kit only had a 3X barlow, a 20mm and a 4mm, no filters. I found them to be plastic lenses, I did purchase coated midrange eyepieces to widen the usefulness, a 15mm, a 9mm, a 6mm, a 5.5mm to add to it. I also purchased filters that didn't come with the scope, a 15 deep yellow, 58 green, an 80A blue, an oxygen-III nebula and a moon filter. I figure if I do go bigger, I will have what I need. I did spend more than I would have aloud myself (please don't tell my wife), however I now can re familiarize myself with the ranges of observation. Thanks again Hi tripod tipper, sorry I misread your original post and though you were just entering the hobby rather than re-entering. Good luck with your new collection! Link to comment Share on other sites More sharing options...
Dave In Vermont Posted July 28, 2016 Share Posted July 28, 2016 To go with Patrick's post, here's another EP chart for you to peruse: Enjoy! Dave Link to comment Share on other sites More sharing options...
tripod tipper Posted July 28, 2016 Author Share Posted July 28, 2016 Becka, No problem at all. After 30 years absence and the change of technology, I'm bound to need some help adjusting I appreciate your input. Buy the way, isn't spellcheck great?. Link to comment Share on other sites More sharing options...
beka Posted July 28, 2016 Share Posted July 28, 2016 13 hours ago, Dave In Vermont said: To go with Patrick's post, here's another EP chart for you to peruse: Enjoy! Dave Hi Dave, nice chart but I don't understand the key. Link to comment Share on other sites More sharing options...
Putaendo Patrick Posted July 28, 2016 Share Posted July 28, 2016 They are the different types of glass used in construction: Key to the glass types: names examples A) Phosphate Crown B) Borosilicate Crown BK7 C) Hard Crown K5 Zinc Crown D) Soft Crown (C, D: Crown) E) Crown Flint Telescope Flint Short Flint F) Extra Light Flint (or E and F) LLF6 G) Light Flint LF5 H) Dense Flint F2 I) Extra Dense Flint (or I and J) SF8 J) Double Extra Dense Flint SF10, SF6 K) Light Barium Crown L) Medium Barium Crown BaK4 (K, L: Barium Crown) M) Light Barium Flint BaLF4 N) Barium Flint (or Q and R) BaF N10 O) Dense Barium Flint Borate Flint P) Dense Phosphate Crown Q) Dense Barium Crown (or L and M) SK2 R) Extra Dense Barium Crown SSK N5 S) Lanthanum Crown T) Lanthanum Flint EK-325 U) Dense Lanthanum Flint Phosphate Flint V) Dense Lanthanum Crown W) Fluorite Crown FK51 X) Titanium Crown Y) Extra Light Titanium Flint Z) Light Titanium Flint AA) Medium Titanium Flint BB) Dense Titanium Flint Link to comment Share on other sites More sharing options...
beka Posted July 28, 2016 Share Posted July 28, 2016 7 minutes ago, Putaendo Patrick said: They are the different types of glass used in construction: Key to the glass types: names examples A) Phosphate Crown B) Borosilicate Crown BK7 C) Hard Crown K5 Zinc Crown D) Soft Crown (C, D: Crown) E) Crown Flint Telescope Flint Short Flint F) Extra Light Flint (or E and F) LLF6 G) Light Flint LF5 H) Dense Flint F2 I) Extra Dense Flint (or I and J) SF8 J) Double Extra Dense Flint SF10, SF6 K) Light Barium Crown L) Medium Barium Crown BaK4 (K, L: Barium Crown) M) Light Barium Flint BaLF4 N) Barium Flint (or Q and R) BaF N10 O) Dense Barium Flint Borate Flint P) Dense Phosphate Crown Q) Dense Barium Crown (or L and M) SK2 R) Extra Dense Barium Crown SSK N5 S) Lanthanum Crown T) Lanthanum Flint EK-325 U) Dense Lanthanum Flint Phosphate Flint V) Dense Lanthanum Crown W) Fluorite Crown FK51 X) Titanium Crown Y) Extra Light Titanium Flint Z) Light Titanium Flint AA) Medium Titanium Flint BB) Dense Titanium Flint Thanks Putaendo, I understood that they were different kinds of glass but I do not fully understand the numbers on the axes. I imagine the vertical one is refractive index but I have no clue what the horizontal is. Link to comment Share on other sites More sharing options...
Louis D Posted July 29, 2016 Share Posted July 29, 2016 11 hours ago, beka said: I imagine the vertical one is refractive index but I have no clue what the horizontal is. I believe it is dispersion. Link to comment Share on other sites More sharing options...
DannyLee Posted August 10, 2016 Share Posted August 10, 2016 to be honest, who cares what the glass used is? Unless you actually make your own, The point is does the eyepiece work or not? I know I have no idea and no interest in such details Dan Link to comment Share on other sites More sharing options...
beka Posted August 11, 2016 Share Posted August 11, 2016 13 hours ago, DannyLee said: to be honest, who cares what the glass used is? Unless you actually make your own, The point is does the eyepiece work or not? I know I have no idea and no interest in such details Dan To some (like myself) in the hobby, its as much about the equipment as the astronomy itself. Like in other hobbies (cars, watches and so on) it is an appreciation of the the precision manufacturing processes and skilled workmanship that is involved in the creation of these products. On the practical side, the types of glass are sometimes mentioned in the specifications of equipment like ED of FPL so if you know these, you are more informed about what you are buying. Link to comment Share on other sites More sharing options...
John Posted August 11, 2016 Share Posted August 11, 2016 It's not the glass thats used that matters, it's the combination of glass types that is key together with the quality of figuring, polishing, coating, mounting and baffling. Get any of these wrong and optical performance suffers. It's also rather difficult to work out exactly what glass types are used in eyepieces, and some scopes, because the manufacturer / brand regards this as proprietary so won't reveal them other than in general terms. Link to comment Share on other sites More sharing options...
tripod tipper Posted August 12, 2016 Author Share Posted August 12, 2016 Hey, I thank you all! In middle school, I learned much about optical science. The grafts and pic's in this thread are actually re acquainting me with the optical sequencing of the telescope and microscope. At the age I am now and from suffering a depilating cranial event, I'm just glad the technology has progressed to a point that I can enjoy the benefits. I try to make sense of it, it just want to look again at the spectacular scenes of our galaxy. BTW, optics were mastered several decades ago. I remember looking at a photograph of New York City from 50 miles away and at an altitude of 40,000 feet. Absolutely crystal clear. In my opinion, the progression of optics is already settled. There are no proprietary solutions. Just enjoy the view!!! Link to comment Share on other sites More sharing options...
tripod tipper Posted August 15, 2016 Author Share Posted August 15, 2016 I was just re reading this thread, BTW, I did find proprietary combinations to be true, (I stand corrected). coatings and lenses do add an element of precision and ads to the cost. I am an obsessive person, I read everything I can about astronomy as I have for many of my past hobbies. There's just something about knowledge that an obsessed person as myself finds satisfying even in the indulgence of this science. Please keep the info coming! When it's cloudy I research and learn. Thanks, Dennis Link to comment Share on other sites More sharing options...
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