Celestron71017 SkyMaster 25x100mm Porro Prism Binoculars with Multi-Coated Lens, BaK-4 Prism Glass and Carry Case, Black

BACKGROUND:I am an amateur astronomer and Vice President of the local Astronomy club. I ownseveral pairs of large binoculars and have looked through many more. My needs werebeautiful images of deep sky objects at a price I could justify. The Celestron 25x100Skymaster Binoculars meet those needs.GENERAL COMMENTS:The binoculars arrived July 2004 and had a collimation error of about 1 degree (verybad collimation). Celestron support was contacted at the request of Amazon supportand confirmed what I already knew, factory repair was required. I lacked the skillsand equipment to collimate and refill with nitrogen. Amazon promptly picked up thebroken pair and delivered a new pair in just a few days. What a difference a few daysmade. The new pair was packaged inside a secondary box and arrived in pristinecondition. Daytime collimation was excellent. We tested the binoculars afterastronomy club on a distant lighted sign and found them to be essentially flat to theedge of the field of view with a minor vignetting at the edge. Everyone was impressedand several members wanted a pair. During the club meeting I suggested thateveryone who wanted a $500 pair of binoculars for $250 needed to go to Amazon andpurchase one before the price went up.I sky tested the binoculars a few nights later and they performed very well. I had onlyabout 20 minutes till the clouds took over. Due to the high humidity and generallypoor observing conditions we were unable to use the binoculars for an extended timeand get a really good test.A tripod is pretty much required for astronomical observing although you can lay onyour back and observe the zenith. You have to hold your breath and squeeze up tightto get a steady image. I was able to hand hold the binoculars during daylight andlook at distant trees, etc. It was very difficult to hold the binoculars with one hindwhile adjusting the focus with the other. Leaning the binoculars on a steady objectsuch as a fence would probably work. Note that not just any tripod will work (readbelow), so if you used these in the field you will be packing a lot of weight. Irecommend that they be used pretty close to home or car.CONCLUSION:But, based on what I have already seen, this is the best buy for the money I havemade for astronomical equipment.CAVEATSI highly recommend purchasing these if:1. you can handle the weight (these puppies are heavy)2. you want to see bright images of distant objects3. you can deal with lack of center focus (not good for moving objects)4. you are very careful not to jar them out of collimation (big binoculars are easilyknocked out of collimation5. you want excellence, and also a bargain (better binoculars are availablefor an order of magnitude more money. 6. you have a sturdy tripod(I have a Bogen which cost over $100 25 years ago and it seems barely adequate).IRRITANTS:1. First pair arrived in only the product box and I suspect that may have contributedto the collimation problem. You should be ready to send a pair back if they do notdeliver a good image.2. the "built in" 1/4-20 threaded adapter which attaches to the tripod head isundersized and has movement. There is a single screw which was not tight on bothpairs which when tightened would slow the play of the center shaft. There is a plasticsleeve between the adapter and the shaft which had play and this could not beremoved (again, same problem with both pairs). When the know was tightened to themax the binoculars were still not very snug. The result is that if there is anyunbalance in the weight on the tripod then the adapter is unable to hold the weight ofthe binoculars and the binoculars will swing to a more balanced position. I believe thatthe solution to this problem is to build one of the "binocular holders" seen in "Sky &Telescope" or "Astronomy" magazines which will hold the binoculars steady whileproviding a counter balance. Otherwise, you will have to be extra careful. Also, thetightening know should be larger for people like me who do not have the strength ofsuperman.3. there is an old adage that the mount is half the price of the telescope. A mountwhich fully supports the binocular tubes at both ends would perform better than theinadequate mount provided. For those mechanically inclined, the solution is straightforward and inexpensive. It could take 10-15 hours of time (at least for me).

This was my first pair of any kind of binoculars. After researching and combing reviews for 2 months in all sizes and configurations applicable to stargazing only, I purchased these knowing they might go right back...and three sessions with this thing was all I needed to get the refund process started.Why?BECAUSE THE VIEW IS GORGEOUS AND I WANT MORE LOLHonestly, I love these, but I knew that if binocular stargazing gave me a considerable experience to go with my Cassegrain, I would want more than 25X. Even at that power, these 100mm's made starscan sweeps that peppered your view with 10X more stars than you'll see naked eye viewing in remote locations. I'm positive that a smartphone holder and motor mount would have pulled up a few nebulas straight to my gallery, but it's already on its way back.I'm 6'4 with an IPD of around 68-70(?), quick pivot adjustment and I confirmed collimation was A+ out the box. That seemed to be the biggest complaint with these larger binoculars during my research, Celestron came through on that part. The nylon carry case is adequate and sensible, I see other brands with hard cases and as a 25+yr Pelican user, I honestly would get my own Pelican for something this big and valuable instead of trusting a no-name brand case to hold up. You need a parallelogram mount. I also lift and stay active regularly, I was able to hold these steady, but it was not as enjoyable as me mounting them and things being a lot smoother. Do not use a regular tripod unless it's something super heavy duty. I used a Bosch construction tripod meant for laser levels, it was overkill, but imagine this precious beauty smacking the ground. No lolAll all in all, Celestron delivered here, my thing is for the size, weight, and mount/tripod integrity investment, once I personally commit to that level, I'm okay with spending a bit more to get more power. If all you want to do is stargaze and not view nebulas or planetary rings in real time, these are perfect and priced with considerable value in mind for that purpose. If you want more than that, you can stick to telescopes the same price or a little cheaper that will give you a bit more power or you'll no doubt jump up to the $1K-2800-5K+ binocular offerings that allegedly give you the best of both formats, accept 1.25 eyepiece variations, filters, etc.I conclusion, you're not losing here, there is value and quality, you will get an eyeful of stars and lunar mountain ranges...but once you get hooked, you will want more.I would have kept these if I felt I would get at least 2yrs satisfaction without any immediate urge or ability to upgrade before then.