very happy. Second? In the 1990s Meade instruments came up with a new design for the Meade 4000 line similar to Plossl that added a fifth glass element on top of the two pairs (4 total). The 5-lens-element pseudo-Masuyamas that telesonic mentioned are/were fine eyepieces. This 10 mm Orion Sirius Plossl Eyepiece is a great, moderately high power ocular for observing small planetary nebulas and globular star clusters, as well as for planetary probing when seeing conditions don't permit higher magnifications. Kellner eyepieces use three glass elements in two groups to minimize color fringing. Disclosure - If you buy something via our link, we may earn a commission with no additional expense to you. Im just starting out with astronomy and this really helped my understanding. Plossls cost a bit more than the Kellners as Plossls are expensive to manufacture because they require good optical glass and precisely matched concave and convex doublet surfaces to prevent internal reflections. I think you will change your mind. https://telescopicwatch.com/celestron-8-24mm-zoom-eyepiece-review/. As long as you take good care of them, Plossls can last you a lifetime, and you will be able to use them with your next telescope if you upgrade at some point. Note to spectacle wearers: Plossl eyepieces with 15mm and longer focal lengths are good choices for spectacle wearers but for shorter focal lengths the Celestron XCel LX series have greater eye-relief so are better suited. Plossl eyepieces have wider fields of view than Kellners. About Us | Privacy Policy | ContactLittle Astronomy is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. For what it is worth, a slow scope like your CPC9.25 (f/10?) Are there any good low-cost 2 EPS out there? Then there is the rule of thumb to avoid duplicating focal lengths when acquiring eyepieces. 1.25" 6.3mm 32mm 40mm Plossl eyepiece set give you a good variation in magnification for a wide range of targets with extra sharpness and long eye relief. For our experience level, would you recommend changing anything right now? 11 = 163 = .5 The Baader offers wider fov, but at quite the price premium. It allows each eyepiece to provide two magnifications. Now we can establish a target magnification range. We have compared Plossl against Kellner eyepieces in a previous article. I can say that most of my plossls have been replaced by other eyepieces for various reasons. If I had to give them all up and keep only one eyepiece, It would be the BH Zoom. Plossl and Kellner eyepieces are two very common examples of a simple eyepiece design, and they are probably the most common type of eyepiece you are likely to come across when eyepieces have been bundled with a telescope; they are also a very common aftermarket accessory. Aspheric and Plossl Plossl are both lens designs that can be used in most telescopes. Simple Plosels work well and unless you have money burning a hole in your pocket, I would start with simple affordable eyepieces. Which is Stronger? But I think you will feel more confident about your purchases and be less likely to be disappointed if you read through the guide. For astronomical observations, such as viewing craters on the moons surface from Earth, high-magnification models are preferred because they offer more detail. They also offer more eye relief than Plossls at the shorter focal lengths. These "other" ones I speak of, aren't technically that, they are a 5 element eyepiece, of a different design. Once I knew how much I liked the zoom I upgraded to the Baader Hyperion Zoom. Differences and Similarities. Something in the 30 to 38 mm range with a 65 to 70 degree AFOV. Most of Celestrons entry-level telescopes are sold with Kellners (and other cheap but reasonable-quality designs like RKEs or Konigs), whereas their more expensive SCTs tend to come with a single 25mm Plossl. Offered in both 2 and 1.25, these are excellent eyepieces. In 1860, Georg Simon Plossl invented the Plossl eyepiece. A 32mm Plssl is worth it. Put the zoom on the Barlow for the high range. Can You See The ISS With A Telescope? It appears to be a custom-made 90 degree binocular built from two 90 degree diagonals and binocular-size objectives attached in place of the usual OTA. Celestron - 1.25" Eyepiece and Filter Accessory Kit - 14 Piece Telescope Accessory Set - Plossl Telescope Eyepiece - Barlow Lens - Colored Filters - Moon Filter - Sturdy Metal Carry Case. One of the main drawbacks of this eyepiece, though, is the eye relief. You have to decide how fussy you are about the edges and what your budget can tolerate. I have personally tested a few Super Plossl and compared them to their regular counterparts by the same brand. The result in magnification is the same and the eye relief associated with the eyepiece is retained or, in some cases, actually lengthened a bit. I agree with your comment on zooms for kids. Their eye relief is limited to about 70-80% of their focal length. Understanding and using a Barlow Lens It comes with 1.25 Plossls 25mm (26x) and 10mm (66x) eyepieces. All the rest will likely be 1.25. Lets give an example. They are just OK, but I dont recommend them, especially in a low focal ratio scope. That is a really interesting picture. There are three types of Plossl eyepiece: the regular, Super, and Orthoscopic. i did buy an astro-tech 3.2 paradigm ed from a cloudynights.com forum member. In the world of eyepieces, when you want the very best, turn to Tele Vue, but be prepared to pay a truly premium price. Note that the full moon appears to be approximately .5 degrees across, so use that as a mental reference when looking at the numbers. Kellners can be as little as half the price of a Plossl in the same focal length, but they are generally very comparable, especially in recent years as telescope prices have fluctuated in response to changing supply chains and demand. 1200 mm FL scope / 10 mm FL eyepiece = 120X, 40 degree AFOV / 120X = .33 degrees (less than 1 full moon wide), 60 degree AFOV / 120X = .5 degree FOV (about one full moon with no space around it), 82 degree AFOV / 120X = .68 degree FOV (about one full moon with a star field around it to frame it). It sounds cool, they must be better than regular Plossls with that name, right? I guess my curiosity is mostly about the diagonal. If you cant use 2, that 32 mm Plossl, which has a 50 degree AFOV, will give you about as wide a field of view as you can get in a 1.25 eyepiece. Interesting points Philip. The view being presented to your eye in a low power eyepiece minimizes everything from optical aberrations in the telescope, to distortions from thermals or atmospheric conditions. Learn more about our story and the team behind the scene. You will see these under many brands, including Orion, Celestron, GSO, and others. So its best for use during duller times when there isnt much brightness visible. PS. Required fields are marked *. These are effectively simple designs like Plossls, Kellners, Konigs, and RKEs, with long focal lengths, that have a lens included to increase their focal length. If you upgrade the telescope or add a second one, the eyepieces will work on that telescope too. Some brands will add better lens coating, darker edges, or a higher quality case to their Super Plossl products, but strictly for performance, there isnt a difference between the two. Optics manufacturers began selling and popularizing Plossl eyepieces, albeit with a generally simplified design where each achromatic doublet had the same focal length. I do not miss beating my eyelashes against a 9.7mm Meade Plossl that I used to own. Eye Relief: This refers to how close your eye has to be to the lens in order to see the full field of view. Plossls are the clear winner here in most cases, unless you have one of the wider-field 50-degree Kellners. An Austrian inventor Georg Simon Plossl came up with the Plossl eyepiece design in 1860. The Plossl's are very easy to modify, allowing me to use the bino-viewer on, all my refracting telescopes without having to cut down the tube length, p.s. I beleive this is the same as they ones you asked about. You could say Super Plossls are not much more than a marketing tactic these days. I am considering buying another eyepiece, maybe 6mm, and a Barlow, maybe 2x, to give me a wider and higher range of magnification. The reason a plano-convex lens is good for using with a telescope is that it provides for both magnifying and erecting the images. You might be able to find a Kellner, or perhaps a high-quality Orthoscopic. I did sell them all when I adopted Dioptrx, and the Naglers are amazing! dnrmilspec is right. Omni 12mm Eyepiece - 1.25" Learn More. If you do choose to go with a Plossl eyepiece, I highly recommend spending some extra cash to get yourself a decent good quality branded Plossl eyepiece rather than going for a cheap, generic eyepiece which is a Plossl only for the namesake. 32 mm = 18.75X12 mm = 50X8 mm = 75X6 mm = 100X4 mm = 150X3 mm = 200X. I am not aware of an ES branded 70 degree series in the USA, but they do have a Bresser branded 70-degree series. Meade went back to the drawing board and they removed the fifth element, keeping the original Plossl design, however, they kept the Super Plossl brand and added some premium materials. In the next section, we will talk about the AFOV of an eyepiece. This is a good thing, because normally the shorter the focal length of the eyepiece, the less eye relief you have. Im fairly picky so would extend budget for better eyepieces if its worth it. Even though the design has existed for more than a century, it has stood the test of and is still today the standard against which other eyepiece designs are measured. High-quality Plssl eyepieces provide high contrast and sharpness across the entire field of view. I want these as possible as wide, magnification and astrophotography purpose. Best suited for telescopes with f-ratios f6 or slower. You have a very wide choice of brands and styles to choose from. Note that we also gained a 16 mm magnification at no additional cost. https://telescopicwatch.com/best-barlow-lens-and-how-to/, Celestron 8-24 Zoom Review Pentax K-70 Astrophotography: The Ultimate Camera on a Budget! In this case, I am going to define this by the focuser and eyepiece size. Yes, eyepieces is a large and complex topic. Do you need a 10 mm planetary and a 10 mm DSO eyepiece? Thanks for going through the entire post. So I sincerely hope that this article helps you understand the similarities and differences between Plossl and Kellner eyepieces so that you can an informed decision and choose the best one for yourself. A zoom eyepiece works like the zoom lens on a camera. Note that the price categories are approximate, as prices can vary between retailers. They include links to them where they can be ordered. I just added the 4.7 mm. No results, please adjust your filters. now it all makes sense, you did a great job explaining all this information it was a lot to take in but i have it now. Many thanks. You have selected a very good starting telescope that will serve you for many years to come. That said, I should also tell you that not all Plossls are created equal. Better edge correction with a short-focus telescope is one of the things you pay extra money for, and sophisticated eyepiece designs have as many as eight elements. Despite one being fundamentally superior to the other in terms of image correction, Kellners and Plossls are generally quite comparable in terms of the image you actually see. Gosky Plossl 40 mm Telescope Eyepiece - 1.25inch This is probably the worst eyepiece I can recommend. I must say Im quite confused about eyepieces. So, for your 30 mm, 82/60 = 1.36 degrees. Rating (max 5): These are highly sought after ep's, and hold their value well. This is where the second formula comes into play. I have an SCT and my eyepiece case only hasPlssls (and one Ortho) in it. Edited April 23, 2010 by russ teh_orph Members 28 198 Author . This will give you a maximum target for planning purposes. So speaking of the Barlow as if it modifies the FL of the eyepiece, while technically not correct, does provide an easier model to understand the net effect. They are also really sharp. I would expect it to be similar to the Celestron in image quality. 4mm Eyepiece vs 20mm Eyepiece. Look those up, seeing and transparency in the context of astronomy. Age is not part of the equation. A Plssl is probably as good as any 32mm eyepiece in a 1.25 inch focuser. I generally use my 40 to search for DSOs so Ill probably replace that one at some point too. Are plossl eyepieces still worth it? I also like to have my face physically in contact with the eyepiece (or the eyepiece cup) so the tight eye relief of the shorter focal lengths actually works really well for me. The Plossl was also called a Kellner Type III in some earlier references; in the 1950's, Edmund Scientific sold a "Kellner" eyepiece made from war surplus lenses, but it actually consisted of two achromats in the classic Plossl configuration. If you do upgrade, youll probably want to go for a different eyepiece design than a Plosslsomething with a sharper image or a wider field of view or a longer eye relief (or all three.). When I was getting my start in the hobby, I bought an ultra-cheap ($15?) If you are very demanding and must have the very best, this is where you want to be. They deliver sharp images in almost all telescopes. The only one not in the article is the Orion Q70 which is available in 38 mm, 32 mm and 26 mm. I possess an embarrassing array of fine eyepieces with names like Ethos and Nagler and Delos. So, even if you have a Maksutov-Cassegrain scope, you should get a good experience from this eyepiece. The Astrovid 40X60mm Zoom Telescope Camera Lens Kit is a great choice for those looking to get a variety of lenses, at different magnifications. If you read the article you know how to calculate the magnification and field of view. NEW. The Big Bang Optics is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. The design uses a planoconvex, two cemented-element eye lens and a large convex field lens. When discussing eyepieces, you will hear people comment on how well the eyepiece is corrected. If you stumble the first few uses, dont be discouraged. This is the link to the eyepiece I am looking at potentially buying, would you recommend this over the Orion one or vice versa do you think? It should list what size eyepieces you can use. Depending on your budget, if you only have limited funds and are just starting to fill out your eyepiece collection I would go with the zoom, then zoom with Barlow. This is important to keep in mind because it means brands have to try really hard to one-up each other because the competition in a niche hobby such as astronomy can be fierce. When selecting the best eyepiece for you, consider: Eyepieces are standardized so whatever investment you make today, the eyepieces will continue to serve you in any future scopes you may own. I purchased the Celestron Starsense 102mm refractor, focal length 660mm, stated highest useful magnification is 240x; it should arrive in about 2 weeks. This eyepiece was even better at correcting false color fringing, but because of internal reflections, the glare was even worse. The first group is made up of a convex lens and concave lens, while the second one has four small cylindrical lenses that work together to magnify what you see through them for your viewing pleasure. Choose three focal lengths. As we go along, I will refer back to these, so dont worry if you cant answer the questions or understand the formulas now. Depending on how fussy you are about having a completely clean image across the visual field, if you have a lower focal ratio scope you will want to look for eyepieces with a reputation for being better corrected in low focal ratio scopes. But with 2 eyepieces and a Barlow, you have the full effective range of your telescope. Another really helpful article, Ed. Worth it is a tough question to answer. Kellners are the other popular design for amateur stargazing, go ahead and check out that article if you want to dive deeper into the subject. In that respect, they are similar to the Explore Scientific 82 degree mentioned earlier. The Expanse is a lens that provides an extra sharp image, and it also has a wider field of view compared to the Plossl eyepiece. When a beginner is choosing eyepieces on a budget, there are a number of possible designs they may choose between. - 32mm plossl. This four-element Plssl design is the most popular eyepiece optical design that gives you excellent image quality, good eye relief, and a 50 to 56 degrees apparent field of view. THANK YOU x 12! Was $38.99 - $99.99 Now $31.19 - $84.99 Compare Orion Edge-On Planetary 1.25" Eyepieces https://telescopicwatch.com/?s=barlow, Best of luck with your new telescope. Its made up of four lenses in two groups. As you learn more about astronomy and you gain more experience with time, you may want to move to Plossls or even higher-quality eyepieces. Regular Plossl eyepieces with maybe just a slightly better coating or build quality. The ES is actually slightly cheaper than the Orion but my understanding from your reviews and replies is that ES might actually be the better eyepiece have I got that right? Omni 32mm Eyepiece - 1.25" Learn More. I can recommend these with confidence. Inexpensive Plossls that are manufactured using low-quality lenses are susceptible to internal reflections when viewing bright objects at high magnification. Not everything in the sky benefits from high magnification. Thanks for your comment. They have a 60deg apparent field, long eye relief, adjustable eye shield and extremely well corrected. Plssl's were top of the line at one time, and are still being sold today, so that says something too. However, i can read very well without my glasses with almost microscopic vision and can use my binoculars without glasses. A large field lens makes the ocular easy to look into. Each eyepiece gives you a unique magnification based on the formula listed at the start: Why do you need more than two eyepieces? This determines how much light the telescope will gather. To achieve a maximum of 200X (2X the aperture of 100 mm), we solve for the focal length. These lenses are connected together. A Plossl eyepiece has a lens thats plano-convex, which means it is flat on one side and convex on the other. Explore Scientific 68 34 mm or ES 82 30 mm would also be good choices at a significantly higher price but with better edge correction. A common problem are eyepiece kits, which are big boxes that some telescope suppliers will sell you with half a dozen eyepieces, most of which include annoyingly short focal length Plossl eyepieces. This number can range from 30 degrees to 120 degrees. 6.5-ish mm (100x & 200x) They also have good eye relief, making them comfortable to use for extended periods. I think Id really enjoy a zoom for all the reasons you mention, But Im having a difficult time assessing how much weight to put on the field of view of given eyepieces. Where a difference can show up is that a lower number focal ratio scope will make it harder for an eyepiece to provide a uniformly good, in-focus image all the way across the field of view due to the steeper angle that the light arrives at the edges of the eyepiece with a low focal ratio scope, as compared to a high focal ratio scope. Outstanding job Jack. Eyepieces under $100 each are generally considered budget or low-cost eyepieces. OK that makes sense, many thanks. I also have a 25mm plossl and am happy with that. While I also have the Baader Hyperion Zoom, mentioned later, I continue to make use of the Celestron, especially in my smaller scopes. This is my all-time favorite eyepiece and the one I use more than all the others put together. 2019-2023 Little Astronomy. I would suggest you also get a 2 low power wide view. SVBONY Telescope Eyepiece Set Telescope Accessory Kit with 2x Barlow Lens 4 Element Plossl Design 6.3mm 32mm 40mm for Astronomical Telescopes. The ocular for your highest visual acuity - for viewing deep-sky objects and the like - should have an exit pupil around . Do I need an adapter if my scope has a Plossl lens? Omni 9mm Eyepiece - 1.25" Learn More. The telescope comes with a 2x Barlow so I was thinking of getting one of the zooms you recommended. As we continue, what would you recommend adding first? However, for your extra money you get the finest manufacture, the best polish and coatings available. https://telescopicwatch.com/best-astrophotography-telescopes/. eyepiece shows signs of use with caps and bolt case, 32 mm Plossl very good cond. Would a higher magnification eyepiece help do you think or am I already pushing my telescope (XT8) to highest sensible magnification I can with BH zoom on setting 8mm and 2x Barlow? If you go this route, you can always add single focal length eyepieces along the way to serve specialized purposes. A good modern eyepiece like a BST starguider 12,8 and 5mm are excellent eyepieces. Good value. With your glasses on, you simply cant get your eye close enough to an eyepiece that only has 10 mm of eye relief. ES 82 degree series plus 1 meade uwa @20 mm with 1800 focal length optical tube lowest mag 51 x / highest mag 300. The Wiki article(s) were very good if anyone else is confused. Here we have very good eyepieces with some extra features. In the case of the Celestron, you get all the focal lengths from 24 to 8mm in one eyepiece that costs $100. Understanding and using a Barlow Lens short answer: yes. Plossl eyepieces are perfect for astronomical viewing because the field of view is wider. Most modern telescopes use a focuser, or diagonal, that accepts 1.25 eyepieces. The big problem with Plssls is that the eye relief is about 0.75 times the focal length. Do you need to have the best to enjoy astronomy? Besides fov, How would you compare the optical quality of the Celestron to the Baader? But the longer FL units are certainly useful. Does having a 70 vs 52 fov make a noticeable difference for double the price? These are things you will want to know and use. FOR SALE! I havent been into the hobby for long but my experience is in line with whats been said. What Is A Barlow Lens For A Telescope? My own lineup (with a C8) is 32mm Plossl, 18.2mm DeLite, and 10.5mm Pentax (the last one not chosen to match, but rather because it belonged to a deceased friend). It is as simple as that. Another way to look at it is that a 30 mm eyepiece in a 3X Barlow works like a 10 mm eyepiece. The only reason it's in this list because of its price and a long focal point. I have to say that your questions are answered in the article. Some will offer longer eye relief which can be important to eyeglass wearers. I think some of these kits even include 4mm eyepieces, and thats ridiculous! Thank you so much for taking the time to provide all this information! Very worth it for me, as I like to use bino-viewers. Tele Vue has eyepieces that approach $1000. If youre still wondering between a Kellner vs Plossl, my advice to you would be invest a little extra cash and go for a good quality Plossl. There are certainly much better options out there but at a significant cost. https://telescopicwatch.com/best-telescope-mounts-for-astrophotography/, https://telescopicwatch.com/best-astrophotography-telescopes/, https://telescopicwatch.com/best-barlow-lens-and-how-to/, https://telescopicwatch.com/celestron-8-24mm-zoom-eyepiece-review/, https://www.amazon.com/Orion-8879-1-25-Inch-Enhanced-Telescope/dp/B000BMPBLK/ref=sr_1_8?crid=3KKUJRXYYN7DI&dchild=1&keywords=telescope+diagonal+1.25&qid=1610887695&sprefix=telescope+diagonal%2Caps%2C512&sr=8-8, https://telescopicwatch.com/orion-skyquest-xt8-intelliscope-review/, https://www.rothervalleyoptics.co.uk/baader-hyperion-mark-iv-8-24mm-universal-zoom-eyepiece.html, https://www.amazon.com/s?k=Orion+Q70&ref=nb_sb_noss_2, https://telescopicwatch.com/best-telescope-eyepieces/, https://www.amazon.com/Orion-8829-Wide-Field-Telescope-Eyepiece/dp/B000M89H7C/ref=sr_1_2?dchild=1&keywords=Orion+Q70&qid=1606584502&sr=8-2, https://www.amazon.com/Explore-Scientific-68%C2%B0-40mm-Eyepiece/dp/B007LMG3F6/ref=sr_1_1?dchild=1&keywords=explore+scientific+68&qid=1606584676&sr=8-1. But for AP you should really start your planning with the mount. ORION SIRIUS PLOSSL 10mm telescope eyepiece 1.25" - $17.01. As you saw in the article, they eyepieces that would be best for you, or your child, is based on your budget and what your goals are. This means you will be able to see a greater expanse for the objects in space but with fewer magnification levels than Kellner or Plossl lenses. They are all made by the same OEM manufacturer. However, if you want to optimize your viewing experience, youll need to invest in a better-quality eyepiece. Omni 15mm Eyepiece - 1.25" Learn More. No price limit? But you may only be able to achieve that rarely. I once had to use a 6mm Plossl to attempt to perform a star-test collimation for a telescope at the observatory. The Big Bang Optics is compensated for referring traffic and business to these companies. Plossl against Kellner eyepieces in a previous article, 5 Budget Telescopes That Are Sneakily Powerful. Features : 5 superior-grade Plossl eyepieces: 1.25-in, 4-element design with a 52 AFOV (32mm has 44)4mm, 6mm, 9mm, 15mm, and 32mm . Brilliant article and I thank you for it, I was literally really confused prior to reading it. You will get varying opinions on this but I would not worry too much about this. In the box you'll receive 5 1.25 eyepieces at following sizes, a 32 mm Plossl Eyepiece, 17 mm Plossl Eyepiece , 13 mm Plossl Eyepiece, 8 mm Plossl Eyepiece, 6 mm Plossl Eyepiece, a 2X Barlow Lens 1.25. Your email address will not be published. The category is over $300 and some of these are way over $300. Remember that visual and AP have very different requirements, so plan on at least two different optical tubes. One more thing if you havent purchased a telescope yet, I would recommend a tabletop version, since they are easier for kids to move than the fiddley ones with spindly legs and complicated dials. Generally, Plssl eyepieces are best suited to Newtonian and fast telescopes. 5-Minute Read, How To Increase The Magnification Of A Telescope; 5-Minute Read. Are Plossl eyepieces any good? These low-quality Plossls lack an internally blackened lens barrel with thread baffles and blackened lens edges and sophisticated anti-reflection multi-coatings, all of which are a necessity to produce an excellent image. The biggest advantage is much better ER in a large ocular. If you are a glasses wearer and plan to keep your glasses on while you are observing, then you will likely want eyepieces with at least 17 mm of eye relief, and some glasses wearers prefer at least 20 mm. By correcting for aberrations, the field of view of these eyepieces could be much larger than the soda-straw field of view in a Ramsden or Huygens, around 40 or perhaps up to 50 degrees. philhas Members 61 459 Location: North East England No surprise there. Imagine you are looking at the moon with each of these eyepieces and consider what you would see. The TFOV of the Hyperion will be greater than the TFOV of the Plssl, but the magnification will be about the same. A four-element eyepiece was made by putting together two achromatic doublets with different focal lengths. How does that field of view impact the viewing experience? I dont dabble in AP. > Click here to jump to the Best Eyepieces section. You see the object in a wider expanse of space with more stars. Most likely it will be used as a loaner eyepiece to go with one of my two loaner telescopes. The eye relief is the distance between your eyes and the eyepiece where you are able to view the whole image comfortably. Again, this is more noticeable in lower focal ratio scopes. I recently purchased the SVBony 7-21 zoom from Amazon. They also offer a generous 16 mm of eye relief which is most important in the shorter focal lengths. 130 mm scope will have a max of 260X for planning purposes. Also, as the apparent field of view gets wider, the image will require more correction. (Focal ratio is a term that refers to the telescopes focal length divided by its aperture. I took notes and now can shop with confidence But, if you have a plan, you can fill in those slots, working toward a well-balanced set of magnifications. In my scopes a simple zoom eyepiece like the Celestron 24-8mm or the Baader has replaced the higher powered plossls. As we go up in price range, we gain capabilities that may not be immediately obvious. Because of this setup, you might also hear a Plossl eyepiece referred to as a symmetrical eyepiece. Tip Its almost always cheaper to buy directly from Agena Astro. There are many more designs that are associated with specific brands, but the ones above are designs that are produced by many companies in one form or another. There is the 56mm Meade Plossl which magically turns my short FL refractors into their own finder scopes. Any 1.25 diagonal should work.