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

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 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.

This is probably a very good buy if you don't already have some fixed power lenses. If you do have a few good ones, I would recommend a 2X Barlow lens.This zoom is very good even on my Explore Scientific ED80 - the low end version, that is. Criterion's and Explore Scientific's scopes can be pretty nice even around the $150 level. I favor refractors over reflectors, as reflectors are quite subject to getting out of line and needing collimating, which is not for the faint of heart.