Zhumell 2" 2x ED Barlow Lens with 1.25" Adapter
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About this item
- Extra low Dispersion glass for sharper views
- Double the magnification of any eyepiece, both 2” and 1.25”
- Brass compression ring Adapter is gentle on eyepieces
Reviews
★★★★★
Verified Purchase
Great Barlow. But some things to know.
Love the Barlow. I am pretty new to telescope astronomy, but with my Orion SkyQuest XT8i Dob, it seems to do its job beautifully without diminishing the view. It is made in Taiwan with ED glass, so it seems to be identical to the GSO one that gets excellent reviews on Cloudy Nights and elsewhere. Mine arrived in a nice padded box, in good condition, in about 2 days which is impressive during Corona Time.
BUT it came with no literature at all, nor is there any manual on the Zhumell web site. So here are some things I have learned in my first few days of using it.
—It works as a 2x Barlow in any telescope that takes 2” eyepieces. With the 1 1/4 inch adaptor in place at the top, it also works as a 2x Barlow with any 1 1/4” eyepiece.
—If you use just the black bottom segment that has the lens in it, you can screw it onto the bottom of a 2” eyepiece and it becomes a 1.5x Barlow. This cannot be done (as far as I can tell) with 1 1/4” eyepieces unless they have a 2” adapter as the Baader Hyperion Mark IV Zoom does. (I bought the Barlow mainly to do this with that zoom eyepiece, which yields a perfect range for lunar or planetary observations with my 1200mm focal length scope.) This also cannot be done (as far as I can tell) with the higher power Televue Ethos eyepieces, because the inner 1 1/4” ring would hit the lens. (Do NOT remove that inner ring on the Ethos eyepiece; I tried that once and a lens of my very expensive borrowed 13mm Ethos eyepiece FELL OUT ON THE GROUND. Oops.)
—Another Big Oops: last night I got confused and instead of removing just the thin upper 1 1/4” adapter, I also removed the thick black bumpy section below it, and slipped just the lower 2 sections (silver and black) into my 2” focuser, thinking that might work as 1.5x Barlow with the Ethos eyepiece. It DOESN’T work with the Ethos because the silver part of the Barlow doesn’t fit into the Ethos’s 2” diameter silver part. Worse, there was nothing to hold it so it FELL ON THROUGH, HIT THE SECONDARY MIRROR AND SLID ON DOWN TO HIT THE PRIMARY MIRROR. Don’t make the same mistake! I still need to inspect for damage now that it’s the next day, and recollimate.
-With my SkyQuest XT8i, the Barlow is the same as any 2” eyepiece in that I cannot focus unless I leave about a finger’s width of the silver part exposed. Gotta get me an adapter one of these days. But the silver part of this Barlow is quite long and has the bottommost black lens section adding to its length for a total of 2 1/2” sticking into the focuser, so it is quite secure even without inserting it the whole way. And since 2 1/2” of the Barlow’s total 4 1/2” length is (normally) INSIDE the focuser, it only adds about 2” (of the bumpy upper black section and maybe the uppermost skinny black 1 1/4” adapter section) to the length of eyepiece sticking up from the telescope. Not bad.
Result: I love the Barlow and thus far with my 8” Dob I am quite satisfied that I didn’t spend more money for a higher end one. Very easy to use as a 2x, and with most 2” eyepieces also as a screwed-in 1.5x. To attain 6mm high power (200x on my scope) in combination with for instance a Celestron or Baader zoom 8-24mm eyepiece, it SURE beats switching to my 6mm Plossl, with its narrow lens and only 5mm of eye relief!
★★★★★
Verified Purchase
Can also be used for 1.5X magnification!
This is a nice barlow and I enjoy using it with my larger 2" widefield eyepieces. It produces clean views, minimal to no perceptible light loss, and also has a bonus 1.5x magnification-- you can unscrew the nosepiece of this barlow and attach it directly to your 2" eyepiece for 1.5X magnification rather than the full 2X. I do notice some chromatic aberration when I pair this with some eyepieces. Nonetheless, this is still a very good, useful barlow, intended for your 2" eyepieces.
★★★★★
Verified Purchase
All metal design.
I'm relatively new to backyard astronomy so I can't really compare this barlow to other makes But what I can tell you is I was impressed by the quality and feel, not cheap plastic junk. After viewing with it on a 2" 30mm, it works quite nicely to give me mid-power range. Dims just a little with a 10mm 1.25" but still can see clearly to me. There are threads on the bottom side so you can screw in filters too. Overall, I think it good for the price, I'm happy with it.
★★★★★
Verified Purchase
Great price and great quality optics
Nice product, well finished, great optics, and super great price. I was a little nervous that this product may be a waste of money, but it turned out too be super. Its optics are perfect, no distortions of stars or DSOs, great clarity and no coma, nor aberrations effects when in use. It has been a great purchase. I strongly recommend.
★★★★★
Verified Purchase
Phenomenal addition to the astrophotographer's kit!
Fit and finish on this barlow is great. It is well machined and, as odd as this sounds, is a pleasure to hold. The clarity of the lens is stellar and and fit my scope perfectly. The 1.25" adapter that comes with it is so well machined that it slowly drops into place when pairing it with the main lens body. It also allowed me to finally get focus with my t7i. Overall ga really great value.
★★★★★
Verified Purchase
I would buy again
It is made in Taiwan. It comes in a nice matte black cardboard jewelry box with foam insert. The appearance and touch of this Barlow lens gives a good feeling about quality. Optionally, you may remove the lens and attach it directly to the bottom of eyepiece to achieve lower magnification. The visual quality was excellent when I tested it with my Astro-Tech 80ED scope, 2 inch Astro-Tech dielectric diagonal and 2 inch Meade 56mm super plössl eyepiece for terrestrial viewing at day time. I cannot wait to use it for astronomy at night.
★★★★★
Verified Purchase
Makes math more difficult!
I haven't received mine yet, but I have to comment on the amazing math skills of the person who wrote the description. "Example: an 18mm eyepiece used in a telescope with a focal length of 1000mm has a magnification of 180x (1000 divided by 18 = 180). when you use your 18mm eyepiece in a 2x Barlow, you will achieve a magnification of 360x"
★★★★★
Verified Purchase
Great Barlow
Awesome fit and finish. Love that the lens can be removed and screwed directly on the eyepiece for a 1.5x in addition to the 2x if left on the tube. Doesn’t leave marks on eyepiece barrel
★★★★★
Verified Purchase
Good addition to lens set
Wanted to add some more magnification to some lens. This Barlow does job the job. Nice clear, display and well made.
★★★★★
Verified Purchase
Solid 2" Barlow
I was looking for a Barlow for my sole 2" eyepiece but they can get expensive at this size. The Zhumell 2" Barlow was at the right price point and is solidly built. I've been very pleased with the overall performance.
Question & Answer
Question :
Is this threaded for a 2" filter?
Answer :
YES!
Question :
What is the focal length of the barlow?
Answer :
It doubles the focal length of your telescope and in effect doubles the magnification of any eyepiece you put in it. If you take the lens off of the Barlow tube and screw it directly to a 2” eyepiece it multiplies your eyepiece by 1.5x.
Question :
I can’t see anything with this barlow lens connected to my apertura ad8 dob with either the 2” 30mm or 1.25” 9mm. what can i check?
Answer :
Not sure what you have tried this far, but keep in mind a Barlow lens will change the focal point through your eyepiece. You might have to start with the focuser all the way out and slowly focus it in until you find where the new focal point is.
Its also possible your focuser is limited by the amount of travel it will allow. I’m not familiar with the dob you have, but I’m assuming by the model name it’s an 8”? Your focuser might not allow enough travel inside the tube. Try seating the Barlow lens into the focuser, but don’t seat it all the way. Pull the Barlow lens out of the focuser approximately 1/4”, then tighten the screws. This will lengthen the focal point and might do the trick. That is the Achilles heel with Barlow lenses and dobsonians that are smaller than 10”.
In any case, you just have to fiddle with it and find its sweet spot. Also, the 9mm eyepiece might be too powerful to pair with a Barlow in an 8” dobsonian. Do some research online to find out how to calculate the “useful magnification” for your specific scope. The 9mm might be pushing if not exceeding that.
Hope this helps!
Question :
Can it be used on Nexstar 8SE's 1.25" diagonal and eyepiece (both ends)?
Answer :
No, the Zhumell 2" 2x ED Barlow Lens will not fit into the NexStar 8SE's 1.25" diagonal or 1.25" visual back.
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