93230 1.25 inch / 8-24mm Zoom Eyepiece, Black/Silver

Very good

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).

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

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.