Celestron - Zoom Eyepiece for Telescope - Versatile 8mm-24mm Zoom for Low Power and High Power Viewing - Works with Any Telescope That Accepts 1.25" Eyepieces

I purchased this in April 2011-after the March Supermoon and it quickly became my primary eyepiece! AFOV is wider than my standard MA (Modified Achromat) eyepieces and the wide exit pupil allows for an easier stance over whatever telescope I am using at the time of viewing. I will admit that while adjusting the zoom the view would often show some distrortion, but, in the beginning, I was able to spin the zoom function back and it would self correct. Over time, that 'self-correction' stopped unless at either stop (8mm or 24mm focal length). Problems: 1) See above for distrortion issues. (Mine may have passed QC by mistake). 2) Weight. Small, beginner scopes are impacted severely. Most impacted are refractors, as they 'balance' on the mount. 3) No clicks during focal length. Must turn on light to see where length is. 4) Overall EP assembly gets loose. I needed to tighten the chrome sleeve to the body of the assembly every time I used it. 5) Mine cracked during use on a cold night? The focus changed and the view went distorted. No visible broken glass, but, something went loose (I can hear it when I shake the EP!) With these things noted, I must say that while it worked- it worked great. I'm not sure if all of the glass was mutli-coated because I did get quite visible reflections- but, the view was clear with a nice big exit pupil. So large in fact, I was able to use a high quality, multi-coated (multi lens) 3x achromatic Barlow lens with it- creating very crisp lunar views under exceptional seeing conditions. However, that only worked on my largest GOTO scopes: a 90mm refractor & 114mm reflector-both of which needed to be balanced with all of that weight mounted. Anything smaller was at risk of toppling over and could not be locked down hard enough to bear the excessive load. So, if you have a smaller manual refractor, say 60mm, 70mm or 80mm or even a smaller manual reflector- make sure that your mount will bear the load and that you can acheive balance prior to buying one of these. Otherwise, you'll be very frustrated! I strongly recommend this EP to someone who has limited funds for buying a variety of high quality lenses. If purchased with a very high quality 2x Barlow, it will cover many lenses that can be purchased separately. I think mine passed QC in error, or was dropped during shipping because my distrortion issues & constant need of tightening haven't been mentioned by other reviewers. Also, I cannot imagine that mine would 'crack' during use, unless something was already defective. Now, I'm hoping that Celestron will repair or replace mine (it's still under warranty), but, I don't want my issues to prevent someone from seeing the value in this pretty high qaulity eyepiece. The glass is very clear, the exit pupil is very forgiving and the views can be tremendous! Clear skies to all! Dave

This zooming eyepiece does a great job, but you need to be aware that somethings do not appear as well as others when zoomed in. This is an inescapable fact of life. Additionally, as with any zooming optical piece, the more you zoom in the smaller the field of view becomes. This means that the object can become too big to see all of it in the eyepiece when zoomed in depending on how big it appears to start with. The moon, for instance, will go from filling the whole eyepiece to just 1/6 of it filling the whole eyepiece. This is, again, just the nature of optics and is no fault of the manufacturer. But for viewing much farther away objects this zooming eyepiece is excellent at making them appear larger, which can greatly increase the detail visibility. Note: there are many objects for which the optimal view is a finite point in the range of zooming. For those objects, it's best to find that sweet spot and not try to zoom in too much. Also, it's best to turn the barrel, the zooming, slowly to find that right spot. The main reason for having a zooming eyepiece is to avoid having a dozen different sized eyepieces, any eyepiece within the range of this eyepiece becomes redundant. Thus, it's fine to have a 4mm eyepiece as this one only goes down to 8mm, or to have a 32mm since this one only goes up to 24mm. The base of this eyepiece has a threaded adapter which allows filter inserts to be mounted to the eyepiece. And, it comes with its own nice protective container. The container has a threaded lid that screws on, and the lid has an extension that fits the bottom of the eyepiece -- the eyepiece fits in the container upside down. The bottom and the top of the eyepiece also come with rubber dust caps. All in all, this eyepiece is very much worth buying for its convenience, function, and the fact that with it one does not need a handful of specifically sized eyepieces.

I'm using this on a Celestron 102mm F5 telescope. While heavier than a standard eyepiece, it eliminates having to change out eyepieces with the chance of dropping one. (I have a old 40mm with a chipped lens from just this). On the Celestron it gives 21x to 63x. Eye relief is ample for eye glass wears at the 24mm end, but shortens down to where you won't be able to see the entire field of view (with glasses) at 8mm. I haven't had much chance to use this yet under the stars, but on things that I could view, the view appeared just about as sharp as with a regular eyepiece. The one major difference you will notice when you receive this is that it is larger and heavier than ordinary plossls. The rubber eyeguard can be reversed so that you don't need to turn it down if viewing with glasses. You may have to rebalance your telescope due to the somewhat greater weight compared to ordinary three and four element single power eyepieces. Stated weight is 4.8 ounces. It also comes in a real nice case with a screw top as well as a rubber top cover and a plastic slip on cover for the bottom. The image appears sharp over the field of view (an F5 telescope is a bit more demanding of eyepieces than say an F10 refractor). So this is a good eyepiece considering that it zooms from 24mm to 8mm. Apparent field of view is 40 degrees at 24mm and 60 degrees at 8mm. Refocusing is necessary in going from long to short or vice versa, but it isn't too much trouble. Much easier than swapping out eyepieces in the dark anyway...

If you're new to the hobby, this is a fantastic eyepiece. You can use the 24mm setting for the widest field of view, and then once you've found something, you can easily and leisurely zoom in up to 4x bigger without changing lenses. "Without changing lenses" is the biggest appeal for newcomers. If your target is centered well, then you might lose your target when physically switching lenses. Even better if you're using a filter -- you don't have to put the filter on and off each individual eyepiece. Just slap it on the adjustable and you're good to go. They say "Jack of all trades, master of none," and that applies here. It's not perfect. It's a little dim at the smaller levels, and (again at the smaller levels) the focus is not quite as clear as a standalone 8mm lens would be. Make sure you're gripping in the right places when adjusting. You wouldn't want to accidentally unscrew the lens. But if you're starting out, and you don't want to spend a couple hundred dollars on a complete set of lenses, this is a fantastic alternative.

I have a 4-year-old son who absolutely LOVES all things space. While he has an over-abundance of adorable curiosity, he has the patience of, well, a 4-year-old. So, changing out eyepieces is a big no-no. By the time I found the object I was searching for in my 25 mm, properly focused, swapped my 25 mm for a 10 mm, and performed any necessary adjustments, my son would be a good hundred yards away playing with something else. Once I would get him back and excited to see what I found, let’s just say it can be difficult to get a 4-year-old to look through an eyepiece without touching/moving the scope. There was too much heartbreaking disappointment and overall frustration while I was trying to harness my son’s curiosity while he played with what is no doubt a “big boy toy.” This zoom eyepiece has been a problem-solver of epic proportions. Not only am I enjoying it myself, but the combination of quality and convenience while also being able to keep my son engaged has been absolutely priceless. It truly is the best of all worlds for the enjoyment of adults and children alike. The quality is shockingly excellent (I purchased in a bundle with a 2x Barlow, which made a HUGE difference), and the ease of use without having to change out eyepieces is priceless. My son’s adorable ooohhhs and ahhhhs when he was able to see the phase of Venus and its proximity to the Pleiades (you’d be shocked what this kid knows already!) followed by the Orion Nebula were worth 10x the price I paid, easy. My only “criticism” is the sheer size and weight of the eye piece. Make sure you secure it well, and I would not be shocked if this eyepiece had enough weight to slowly pull down on a telescope either of lesser quality or that has been “used” a lot. Gravity and such. All-around, I got EXACTLY what I paid for, and this has thus far exceeded all of my expectations.

I’m a novice and this is a great optic for a medium strength telescope. I have a Celestron StarSense Explorer DX and this optic is great for those who are looking for a god quality eyepiece with flexibility. At higher powers you loose some qualify due the additional glass being present in the eyepiece but for those of us who are just starting out and want to easily find, focus and observe stellar objects this is a great choice. It also offers a large eye relief (hole you look through)which is great for anyone who wears glasses or if you have small children. My problem with some of the budget optics I’ve found is that at higher powers the eye relief (hole you look through) is very small and impossible to use for kids and those with glasses. This makes it really easy for my small children to observe objects, even with the clarity reduction at higher powers. It also helps not needed to mess around in the dark changing eye pieces and messing with Barlow lenses and all that jazz. I highly recommend this for anyone who is looking for something to start them off on their viewing journey or for anyone who wants a space saver when taking a trip.

Wow! This eyepiece might never leave my scope! The optical quality is great throughout the zoom range (as much as seeing will allow), requiring only tiny adjustments in focus on my Celestron 8SE. The field of view is noticeably tighter than the standard 25mm piece that comes with my scope, but that actually helps me center objects when aligning. The field of view is still large enough for the goto mount to put the object in view, especially if you know how to use the precise goto function, so that should dissolve your one worry about using this. The zoom is magnificent. Saturn was stunning at mid-high power (the highest power in my scope is over 250x, which is not going to look good in anyone's scope without good seeing), and the view is crystal clear at lower power. I was able to spot at least five moons around Saturn from the light polluted skies of Pasadena, CA where hardly any stars are visible. Higher power dims the image, but I did not notice any strange optical peculiarities. I'm sure there are some, but for me this eyepiece is a dream come true. I was even able to view the ring nebula from my front yard, and with medium power I was able to discern the two protrusions from the edges, a big step up over the meager 80x offered by the standard eyepiece. The ability to zoom on the fly makes keeping the target in the field of view incredibly easy. The piece is quite heavy because of the extra complexity, but doesn't feel overly bulky. The zoom is controlled by twisting the textured part of the outside, which others have reviewed to be rather stiff and difficult to turn. I can't join that chorus, as i have no problem zooming out so long as I grip the smooth base and twist the textured sides. The action is smooth and holds firm. Basically, this thing is amazing. I would pay twice as much for this and still feel like it was a bargain.

Couldn't be happier.Good quality,saves time,space and money if you are just starting out in astronomy and telescopes and are looking for an all in one eyepiece and not ready to spend ALOT of money buying multiple different eyepieces and having to change them out and carry them around then,this is a great starting point that will get you going easily and for much less cost. Image is clear and sharp.Easy to zoom in and out and good eye relief.As a noob myself,I can say this really has made my viewing sessions alot better and less of a hassle.

I first could not achieve focus with the scope I have. This is probably because of the nature of Newtonian reflectors. However, with a zero-profile adaptor, I was finally able to achieve focus. It may also help to use an adaptor that is recessed (negative profile). The zoom feature is great, but image quality deteriorates rapidly at higher magnifications. Still, it is convenient to have the zoom feature, where you don't have to change eyepieces and re-focus while holding the telescope steady in the meantime. The build quality is excellent, although a bit on the expensive side. Recommended, if you have the right eyepiece adaptor (or scope).

Excellent

Great eyepiece to have when you feel like 'surfing the sky'. The 24 mm focal length is nice in viewing the 'bigger picture'. Not quite the 'wide angle' view of my 40 mm plossl, but definitely effective for viewing smaller star clusters. Being able to 'infinitely adjust' the focal length down to 8 mm is considerably easier than changing oculars and having to re-focus, making sure the object being viewed was solidly in the middle of the field of view before zooming in, of course. Images were sharp at the high magnification as well, something I was pleasingly surprised to find. Wish my zoom microscope was as effective. It's a great eyepiece for casual sky viewing with a Newtonian scope; the 'only lens you need' for the most part. The almost-par zoom capability meant little re-focusing adjustment between low (24 mm) and high (8 mm) magnification, so I could quickly explore objects of interest without a lot of need for adjustment. Worked well with the 2X Barlow lens as well, although the light reduction at that magnification with dim objects was very noticeable. Zoom action is a bit stiff; my hope is it's just a built-in 'tightness' as opposed to a lubricant which may become stiffer with winter temperatures. There were no 'click stops' for separate focal lengths, just markings on the outer barrel . . . which isn't a big deal, just an observation. Zooming was always smooth but tight. Solid mechanical arrangement. As is typical for zoom lenses the effective aperture decrease at the higher magnification (8 mm) results in a noticeable dimmng. It was necessary to increase the focal length a bit to be able to still discern a dim spiral nebula in deep space. Viewing the moon was a delight, however, as that is normally so bright a neutral density or double-polarizing filter is necessary to reduce the intensity. Images remained sharp at all focal lengths. Great addition to my accessories . . . but too long to fit into the space I have left in my larger accessories kit. However, don't usually take that with me unless I'm planning a long observation session.

Si bien su precio es elevado, las prestaciones son excelentes. Gracias al zoom evitas el engorroso cambio de oculares durante la observación. Muy recomendable.

super zoom celestron! le modèle qui équipe les longues vues ultima 80.images lumineuses très bon rendu des couleurs un idéal pour tout instrument de qualité . le champ visuel de 40 a 60 degrés est dans la norme pour tout les zoom de haute qualité . le seben 8/24 est l' équivalent! la digiscopie avec le nexyz de chez celestron , /et aussi le apexel tout métal , en xyz ! - est parfaitement adapté ! la longue vue celestron ultima 80 est une valeur sure et son oculaire zoom 8/24 aussi...ce modèle a une jupe en 31.75! génial avec un maksutov 90/1250mm! et autres lunettes achromatique ou apochromatique .à recommander sans hésiter: je pratique l'astronomie visuel avec ,il permet une très grande plage de grossissements! exellents résultats avec un omegon 80/400mm , ,et skywatcher ST80. formidable pour la digiscopie et pensé pour les porteurs de lunettes de vue avec un dégagement oculaire de 18mm à la focale de 24mm , et 15mm à 8mm de focale ! à recommander !! génial : merci à AMAZON pour y avoir accès ; et à ce prix !!