SVBONY Telescope Barlow Lens, 5X FMC Barlow Lens, 1.25” Telescope Accessory

My telescope is 5'' f/5 newtonian reflector. Its usable maximum magnification is about 260X. But, bundled high power eyepiece gives only 65X. Whenever watching moon surface, I wanted more magnification. In theory, 4X barlow lense should be ideal, utilizing maximum potential, but not more. In reality, even 3X barlens was out of reach with its prohibitive price. (Considering the price of telescope itself.) With the help of amazon's powerful sorting by price (from low to high), I met this lense. The price is good and seller's specification says it is APO design, which is typically high quality. But, there was a very negative review from other user. Anyway, I wanted utilize all the potential of my telescope, and I bit the bullet and tried it myself. Fortunately, the result was rewarding. It is a little long and heavy, but it gives high magnification power and clear image quality only for $25. Considering its wonderful price tag, I give it 5 stars. Con This lens is a little long and heavy that it easily breaks the weight balance of telescopes. (So, negative review from other user who mentioned focal length has its own value.) With weight balance broken, the telescope get unstable and pointing get a little tricky. High magnification power of this barlow lens, make the problem worse. Even the slightest movement from unstabilization also get magnified, And the target gets out of the field of view easily. There are 2 common ways to recover the balance. 1. Re-balancing - Loosen the bolt holding the dovetail and adjust the positon and tightening the bolt. - Check if balanced, and if not repeat it again. - No additional monetary cost but irritating. (You should go through this procedure whenever attaching this barlow lens.) 2. Attaching some magnet to the rear part of the telescope, fuctioning as a counter-weight. - Purchasing some magnet means additional monetary cost, but remember?, this lens is such a bargain. - Attaching some magnet is much more convenient than loosening & re-tightening a bolt, and if the OTA does not have dovetail plate, this is the only way. - In theory, about the same weight (as that of this lens) of magnet will be needed. If not sure about the proper size of magnet, purchasing multiple small magnets and adjusting the number of magnet attached, is a safe choice. (Small magnets easily get sticked to each other as a bundle, so handling a large number of small magnets is manageable.) There is also a problem with too high magnification. With 5X, it is so easy to go over the maximum capability of the telescope optics. (Maximum usable manification is usually 2 * aperture in mm.) And after the maximum, image get blurred. In my case, this barlow lens and bundled high power eyepiece together gave about 120% of the maximum, and image quality get degraded a little. Pro At such a bargain price, it gives 5X magnification power with good enough image quality. With low power bundled eyepiece attached to this lens, image quality is quite good. With high power bundled eyepiece and this lens gives 120% of the maximum magnification, and image get blurred a little, but I am happy to utilize all the potential of the optics. Detailed view of the Moon surface is very satisfying. It is good to keep portability with low focal length, and get high magnification, too, with this lens. Caution You need stable mount and well-aligned finderscope (or red dot finder). It feels like the telescope got 5X more sensitive with this lens attached. Unstability of the mount and misalignment of finderscope get also magnified. That's why weight re-balancing is important. Conclusion. A little long and heavy. Easily breaks the weight-balance. But after recovering the balance, it gives 5X magnification with good image quality. It is a perfect fit for short focal lengh telescopes, which typically lacks magnification power. If you need higher magnification, but worried about additional expenditure, I definitely recommend this lens.

Great 5x Barlow. I see that other reviews claim it’s not 5x or 3 element however I disagree. This is a solid 3 element that most certainly is 5x. It is a great addition to my nexstar 8se. There are some sacrifices that you make when using a Barlow of this magnification though. You will see images that are less sharp, sometimes color accuracy will be off, and overall field of view will degrade. That being said, you have to know what you are getting into when you start looking at a Barlow that is more than a 2x.

Poor quality cheap made👎

I have been viewing celestial bodies for over 40 years and yet to come across a 5X barlow lens until now. Wow, that lens doubled the size of Jupiter and Saturn. Moons of Juipter were clearly visible and not just four but six or seven. The moon is awesome; indeed, because I get bored with looking at the craters and mountains. Cannot wait for Mars to be visible and Orion is not at 5a.m. in the morning. Lens is well worth the purchase.

It arrived today and I had it out tonight with my 120mm f5 refractor. I got it because I've never had a 5x barlow and it was on sale for $17. And it's advertised as a 3 element apochromatic. I have 3 other 1.25" barlows, an excellent 3x Celestron 3 element, an equally excellent Astromania 2x 3 element and a very good Astromania 3x 3 element which I couldn't resist because it was so inexpensive. Yeah, I'm cheap. So I immediately did a compare and contrast test with the new toy. If it's a 5x, it's a 5x that produces an image that is exactly the same size...using a 15mm eyepiece...as my two 3x barlows. Just not as sharp and contrasty. Like Lincoln's joke, "If you call it's tail a leg, how many legs does a dog have? Four. Because calling a tail a leg doesn't make it one." This barlow has 5x etched on the side but produces 3x images. It's advert says it is a 3 element lens but I doubt it. 3 stars because for an okay 3x achromatic, $17 bucks is a good price. But the advertising could use some revision. .....3 days later.... This is becoming a bit of a saga and I's not sure it's justified by a $17 dollar purchase, but it speaks well of SVBONY and their desire to be and be seen as a responsible and reputable company. Within hours of posting the above review, I received the following reply: Dear Joseph S Lambie,sorry to interrupt you. You bought SVBONY Barlow Lens 5x from our store and give us Neutral product review:If it's a 5x, it's a 5x that produces an image that is exactly the same size...using a 15mm eyepiece...as my two 3x barlows. Just not as sharp and contrasty. I am really sorry for your inconvenience.It's may be the problem of the whole magnification of the connection of Barlow lens and telescope eyepiece,if the Barlow lens' magnification is high ,when install on the telescope, it may exceed the valid magnification and the observed scene will became blurred, it's not clear, so the Barlow lens is not as bigger as better, Barlow lens and telescope eyepiece are connected together for use, they need to control the effective rate range, in order to clear the effect of observation. There has 3 points about Barlow lens: 1.The Barlow lens ,its role is not just to improve image quality, but also for the comfort 2. Even a well made Barlow will little damage on the imaging quality 3. In order to reduce the influence of imaging, careful selection of Barlow at different magnification,In general,you can make choice of 2x on it. So,the Barlow lens 5x' using effect is not as good as the 2x Barlow lens',dear friend,would you like to try our SVBONY Barlow lens 2x? I would like send you a free new replacement 2x Barlow lens and the original need not return back.You can send me your detail shipping address, so i can send you the new replacement one as soon as possible. Follow up your reply Sincerely, Angela Obviously, Angela's English is a second language, but it's a hell of a lot better than my French. And I got what she meant. If you try to push magnification beyond the capacity of you scope, the image degrades regardless of the quality of your scope, eyepieces or barlow. (Which is something I didn't know when I got my first scope @30 years ago and something most beginners don't know today.) To assure her that my "tests" took this into account...that I tried to make an apples-to-apples comparison...I sent her this reply: Angela, Thanks for your concern. The scope I was using...I have several... is, as I said, a 120mm refractor with a focal length of 600mm. Under optimal conditions, it's maximum magnification is 240-250x. I was comparing my other barlows to your product just to see how yours compared in contrast and sharpness. I was comparing them all at 200x as the seeing tonight was good. That is to say, the 2x barlow with a 6mm plossl, the 2 3x barlows with a 9mm plossl and your 5x with a 15mm plossl. So in effect, all of the barlows would be 3mm eyepieces which would produce 200x magnification in my scope. I immediately saw that your barlow was producing a smaller image than the other 3. When I swapped the 15mm from your barlow to to my 3x barlows, the image size was the same. A 15mm eyepiece with a 3x barlow produces 120x magnification or half my scope's maximum useful power. And the comparisons were made at that power. I conclude that your 5x barlow is, in fact, a 3x barlow. It was also apparent that the image produced by yours was less sharp and the contrast was softer; the background was not as dark. Since your barlow, though roughly the same dimensions as my others, is noticeably lighter I concluded that it probably was a 2 element achromat rather than a 3 element apochromat. Whcih would explain the quality of the image as compared to my other barlows. And for an inexpensive, 3x, 2 element barlow, it's not bad at the price. But it is manifestly not what it is advertised to be. Thank you for the offer of a 2 power replacement, but as I already have an excellent apochromatic one, a mediocre achromat would be of little use. I actually have Meade and GSO 2x achromats gathering dust. Yours would make #3. Assuming that you know your business and that your supplier for your 2 and 5 power barlows is the same, it appears to me that you may have received some mislabeled merchandise. Perhaps you should run some tests of your own. Best regards, Joe Lambie She followed up with a note which says she's sending me their T-adapter equipped 5x barlow anyway and hopes I like it. Dear Joseph S Lambie,thanks very much for your valuable message. It is particularly important to improve our products and we will re examine and upgrade our products, although this process may take a long time. How about that we have the other Barlow lens 5x, the Ads Asin is:B01M15HA0G, i have sent you this new replacement,you can try if this one work well.There i would like attach the screen shot to tell more details about the new replacement. Sorry for your inconvenience again, and please understanding our sincerely mood that want to follow up and solve the problem, so if there anything,please contact me freely and i will be always here for you. Sincerely, Angela Conclusion: Obviously, this company is doing it's best to take care of it's customers and provide decent equipment so I would not hesitate to try them again. The reason I'm amending this review is that I read a bunch of the other reviews of this barlow posted here which I had not done before I purchased it. I seldom read reviews of anything involving the subjective judgement of the reviewer as they nearly all come down to "l liked it" or "I didn't like it", an opinion, without an explanation of how the opinion was arrived at. And when it comes to opinions, I prefer my own. Which is a hold over from 45 years as an actor reading the most egregious nonsense about work and people I was involved with. Finally, what I'm pursuing now, for my own amusement, is is an ongoing experiment to see what can be achieved from a light-polluted site with minimal investment; i.e. low-end equipment. And I am having fun, which, at 73, I try to have as much as I can on a daily basis. For obvious reasons.

I bought a 2x to 3 x adjustable Barlow from Orion for 3 times what this cost, and this Barlow is FAR SUPERIOR! I am recording video on the surface of the moon at a CLEAN magnification of 600 X (see note below) - "ZEKE!!! - THAR BE ALIENS IN THEM THAR HILLS!" (or maybe not) but I can sure see things I have NEVER SEEN BEFORE up there! I am recording it with a $20 bare Sony Effio-E 1000 line resolution CCD Image array crudely (but carefully) mounted to the end of my best 10mm eyepiece and it looks pretty darned good! (eyepieces seem like a crap-shoot to me - getting a good one at a decent price is a gamble, at best) . The video is slightly wavy (as always) from the atmosphere (I need to head for the mountains), but it is still VERY MUCH USABLE! I did increase my chances of this working by collimating the telescope and cleaning a few mirrors and and lenses (it helps). NOTE: Magnification = Barlow Mag. Power TIMES (Telescope focal length in mm ÷ Eyepiece focal length in mm). For my 8" Orion Dobsonian Reflector, that is 600 = 5 TIMES (1200 / 10). I am not sure what the lens material is, but it is WELL ABOVE AVERAGE for quality (for the cost). No, it is not a finely crafted Japanese or German lens, but by golly, whoever is making these things is pretty darned good at LENS WORK, and the machining on the housing is decent quality, as well. I am VERY HAPPY with this Barlow! WAY MORE THAN I EXPECTED. I will add one of my videos in the near future (I need to edit to cut clips out since they are all about 1 Gigabyte - which is a wee bit more than Amazon allows) This Barlow is HIGHLY RECOMMENDED. I'm tickled!

Nice price, but kind of weird effect when i use it with the moon and my dslr camera. The image was really dark, still trying to figure why. 02/03/2019 - I have to apologize, i am new to astronomy and didnt realized the more magnification, the more light is lost. The problem was the magnification, i was expecting the same amount of light, but its working just as expected. I bought a 2X barlow from SVBONY too, the light was better and the maginification was right for the job. So its a 2 thumbs up for the Barlow.

Inexpensive and works just like the celestron version.

Es tal como se esperaba, es lo que yo necesitaba.

ACTUALIZACIÓN El vendedor después de leer mi opinión se comunicó conmigo y me brindó opciones para solventar mi problema. Excelente servicio postventa y puedo asegurar que su prioridad es la satisfacción de sus clientes. Contento con el producto y soporte. ********* Es de buen material y viene bien ensamblado, el detalle es que el cristal viene sucio y no incluye un paño limpiador. Al parecer el cristal no está dañado, pero tengo que esperar al realizar las primeras observaciones con el.

SVBONY telescope accessories are quality with reasonable prices. On top of that, customer service is amazing, specially Angela is a gem, very attentive to questions and requests. I cant recommend enough.

You require a really steady and sturdy mount. It high quality. Not incredible optics but on a budget yes!

Es muy bueno puedes ver con buena amplitud el espacio y en el caso de júpiter lo puedes ver con sus lunas visibles.