The 5 power barlow surprised me. I was weird it would be blurry but it is not . It is sharp and I have been using it to image Saturn and mars . It dose have a down side through it is supposed to be treaded for filters but I have yet to find one to fit and I have orion filters and celestron and mead and opt and zwo filters and they want fit what little treads the the barlow has. That's why I gave it 4 stars
One of my favorite scopes and perhaps my most used is an 80MM, F7.5 APO. It is the perfect grab and go. None the less there is an obvious problem; obtaining high mag looks from planetary objects. Understand that this scope can easily produce good views at 200X and when the sky permits it can be pushed to approx 250X. It is not the scope that is the problem. It is the oculars necessary to achieve that magnification At a focal length of 60MM, the problem is a matter of numbers. To reach 200X I need to use a 3MM eyepiece or an equivalent barlow/eyepiece combo. So, I can go with my 6MM Celestron Elux or my Orion 6.3MM plossls paired with my Tele Vue 3X barlow. It works, but the eye relieve and FOV are pretty restrictive. The answer was either a very expensive 3MM eyepiece or.... a more powerful barlow. So, I noticed the OPT 5X APO barlow. I purchase it on sale for $39.99. I hoped it would help. The results exceeded my expectations. First the construction; the barlow looks and feels well made. It has an unusual cone shape, with a compression ring to hold the eyepiece in place. Even with the normal price of $69.99 it has the presence of a much more expensive ocular. So, I took the barlow out for a test run the first night I had a chance. Last night Jupiter was up and ready for viewing. I paired the barlow with my 20MM Meade Series 4000 plossl. This produced a mag of 150X. The view was great. It was crisp and clear without any distortion. With a FOV of 52 degrees and very nice eye relief it seemed as if I were using a much more expensive eyepiece. I upped the mag to 166X (an 18MM Celestron E-lux) and than again to 177X (a 17 Orion Sirius plossl). The views were pristine. At 200X the images began to break down, but I believe it was due to the sky conditions and not my equipment. The only problem I could discern was the tightness when inserting an eyepiece. However, I believe this will clear up with use. In not way did the barlow did not hurt the views. In fact when combined with a simple plossl it gave me images that one would believe came from a far more expensive eyepiece. So, I can easily recommend this barlow to anyone who has a need to somehow produce high mag from a smaller scope. At the price I paid, it was a steal...
After reading mixed reviews i was unsure about purchasing this 5x. It was on sale so I took a gamble on $35. When it arrived I noted that the inside tube was shiny so I unscrewed the top and painted the inside with chalkboard paint. It is now a rough textured dark tube. That night I tested out the barlow with an 80mm triplet refractor. Every ep was able to resolve well down to 10mm. smaller than that and my refractor becomes diffraction limited. Next I placed a mono qhy5 on the barlow and ran video. It was incredible to almost fill the frame with craters on such a small scope . I would recommend this barlow.