I purchased the Celestron 71008 SkyMaster 25x70 Binoculars on a whim when they were available for $59.99. I already own several pairs of binoculars including the Celestron 15x70 SkyMasters. The 25x70 SkyMasters are very powerful, and have decent optics. There are several drawbacks though. The 25x70 Skymasters have a very narrow field of view, even compared to the 15x70's. For astronomical use, you're going to need a good tri-pod, as they are very heavy, and next to impossible to hold steady enough by hand. Even with a good tri-pod, the included tri-pod bracket is not very good, and will cause the binoculars to shake with any kind of vibration. The optics on the binoculars are good, but not great. In this price range, the optics are more than satisfactory. If you're on a budget and looking for very powerful binoculars, then I recommend the 25x70's as long as you know the limitations. Personally, I think the Celestron 15x70 SkyMasters are a better choice. They have a much wider field of view, and are a little easier to use without a tri-pod.
Edit: Just to add 1 tip. Regardless if you wear eyeglasses or not, if you roll down the eyecups, you'll get a much wider/better field of view. The eyecups aren't an issue on the 15x70 Skymasters, but rolling them down on the 25x70's makes a great deal of difference.
on December 5, 2013
I originally gave these four stars because the focus has play in it. I bumped them up to 5 stars because of the low price and the fantastic astronomical views. They stay in the focus you put them in, but the play occurs only during adjustment. My 16x50 is much better for daytime sight seeing.
1. The eyepiece lens is 23mm, vs 18mm for my Nikon Aculon 16x50, 16mm for my Celestron 10x50, and 13mm for my Tasco 7x35. Despite this, they have the same eye relief as the smaller binoculars, and also a moderately smaller apparent field of view.
2. I followed the exit pupil, drew a triangle, and quickly and accurately measured the apparent field of view of the Celestron 25x70 to be only 57.5 degrees, and that is the maximum no matter where your eye is. My Nikon's are 61 degrees, my Celestron 10x50 is 60 degrees, and my Tascos are 58 degrees. Visual observation confirms these math measurements.
3. They are noticeably heavier than my other binos, but not a lot.
4. They are easy to hand hold very steady in the day time, without resting my elbows on anything. At night it is much better to have something to brace my elbows on.
5. They look like they are good quality, other than the thin strap.
6. They are 10.4 inches long, and 8 inches wide.
7. There depth of focus is less than that of lower powered binoculars, so I really have to adjust them as I aim around at stuff terrestrially at different distances. These are better for astronomy than for birding. My 10x and lower did not need to be adjusted much unless I looked at something really close. My 16x is in between, but still pretty forgiving.
8. The focus is smooth but has a short lag, and requires diopter adjustment of the right eye to compensate for the lag. In cold weather, the focus wheel is tighter than any of my other binos, but still reasonable enough to turn.
9. I am a bit near sighted, so I get a closer near focus at around 50 or 60 feet instead of the advertised 75 ft. My nikons near focus at 18 ft, not their advertised 28 ft.
As many other reviewers already said, the eyepiece barrels seem too big around, and pinch my nose if I try to get closer to the eyepiece. However, if I carefully measure the interpupilary distance, I can place them so I see the full field of view without the pinch. It just does not come as naturally as with my 10x50. I separated them to see if getting one eye closer would give a bigger field of view, but it did not. I guess how close I get is close enough. It just feels weird them being that far out on my nose and making that third point of contact like that. Edit: next day: I'm getting used to the new feeling.
The correct place to hold these binoculars is by the barrels in front of the prisms. That is how to get steadier views. Better yet, slouch down in a chair and put your elbows on the arm rests. Then all you'll see is your heart beat.
I looked at a distant light, and compared its size to the Nikon's 16x. I find it very believable the Celestrons are 25x.
The field of view is not as wide as advertised. The apparent field of view is 57.4 degrees, not 61. The belt of Orion just barely fits in the view. The moon is 30% of the view. The true field of view is 2.4 degrees, not the advertised 2.7 degrees.
The arms of the eyepiece adjuster also have some wiggle in them causing a 1/4 inch delay when turning the adjuster wheel. I have had to re-adjust the right diopter even when I did not touch the center wheel, indicating it might be moving a bit. But it does not take long to get back into focus. There is also a flare visible off to the side of the exit pupil, though I don't see it during astronomy.
Despite these flaws, I can't subtract a star at only $70 shipped. These binoculars are a league above my 10x50 for astronomical viewing, at least in terms of looking at individual targets. A telescope has many advantages, but these are grab and go. However, to see the phase of Venus, you need to stop down the aperture and sit down to brace your view.
I easily saw the correct shape of the Orion nebula on a half moon when my 10x50 could see nothing.
I could see the dark side of the half moon, whereas my 10x50 could only see the bright side. My 16x50 also saw the dark side.
Jupiter looks much bigger in the 25x70, but I may need to reduce the aperture to see the stripes. I can see bands on Jupiter 114mm f8 Newtonian telescope at 28x, but I can't see bands at 25x in the binoculars.
The Pleiades look much better in the 25x70 than in the telescope or my other binoculars.
The double cluster in Perseus is clearly visible in the 25x70, and looks tiny with an almost stellar core in my 10x50.
Andromeda, M31, looks better, with M32 and M110 noticeable by it, and very hard to see in my 10x50.
I can see a tiny ring around Saturn at 28x in my telescope, but at 25x, I sometimes see a ring around Saturn and sometimes I don't. On the day that I could see a ring, my 16x50 detected ears.
I can see M13 and other globular clusters as small fuzzy balls. I could find them in my 16x, but smaller. In my 10x, I can locate most of them, but they look like stars. Maybe I can detect a little fuzz on M13. In my 7x, I can't locate most of them, but I can see M13 and maybe a few others, though I don't remember.
All of my observing was hand held, unbraced.
I could point them at whatever I wanted and hit my targets just fine. I had trouble hitting Andromeda right away because I could not see it naked eye.
M82 and M81 are easy to identify in my 25x70 as I sweep over them. I can see the cigar shape of M82 in my 16x50 too, though I can't find either one in my 10x50.
I can see a mountain range on the moon in the 25x70 when my elbows are braced. I've not yet found it in my 16x50.
Airplanes look bigger but take longer to find in my 25x70.
At 25x, you can't tell where you are in the sky from the star orientations. You just have to point and look, and you know where you are when you see the object you are looking for. At 16x, I can pan around from bright star to bright star and figure out where I am by memory. At 10x, I can see some bright stars in the same field of view, but have to pan for others. And at 7x, you can easily see where you are.
I actually think my view of M31 was more enjoyable in a 15x70 than in these 25x70, though I know the Orion nebula is better at 25x. It keeps getter better even at 60x.
M33 can be located at lower power, but the 25x70 gave the best view, giving maybe a hint of spiral structure.
on October 18, 2015
The 3rd large Skymaster Binos I've acquired and likely to become my favorite. Also have 15x70 and 20x80. About the same feel as my beloved 15x70 and I can hold steady enough for short glimpses without use of tripod. Apart from the next two sentences, my comments regard casual astronomical use. Did take it with me yesterday on the Blue Ridge Parkway for scanning faraway features. Excellent performance and reach for terrestrial viewing yet not as convenient to handle nor as portable as my 10x50.
As others point out, a tripod is recommended if you intend on lingering longer than several seconds. A Bakelite tripod adaptor is included yet I still utilize the traditional metal Celestron one because it provides an extra inch of vertical clearance which eases visual access. While the view is 2.7 degrees, an expansiveness is remarkably maintained. Some observational notes follow, especially in comparison with the 15x70 and bear in mind my suburban skies suffer from light pollution: Saturn was a tease as it is definitely seen as elongated. However, it may be that at opposition the rings just might be inferred. I saw it closer to the setting sun so not a good circumstance. Jupiter was a bright disc and there was greater separation between its moons and disc. Could not resolve it's two dark belts. Venus was a very bright morning star and I could not be assured I could detect its shape with certainty.
The Pleiades (M45) fills the field of view with breathtaking magnificence!! Orion's sword plus the cluster NGC 1981 can be seen simultaneously. The Orion Nebula (M 42) approaches what I can see in my telescope and some of the Trapezium stars can be viewed. NGC 1981 is truly a charming cluster. The very rich open cluster M35 in Gemini is partially resolved while the Wild Duck Cluster (M11) seems just under threshold, appearing more like an irregularly shaped hazy area. However, it might be partially resolved with darker skies. Globular clusters M13 and M22 are larger fuzz balls than in the 15x70. Double star Albireo in Cygnus can be resolved. The great Andromeda Galaxy (M31) truly resembles a comet which provides insight into the false alarms it likely triggered for historical comet chasers like Charles Messier who put it down as #31 on his list of stellar distractions to avoid. The delightful Beehive (M44) open cluster is contained in one view and I can now relate to the imagery of, "The falling tears of Christ" earlier observers reported. The open clusters of Auriga,(M36, 37 & 38) are tantalizing yet, for me, on the verge of resolution. The asterism Coathanger (aka Brocchi's Cluster) fills one field.
All in all, for under $100, the 25x70 Skymasrter is an excellent investment when not seeking higher priced premium binoculars. It is recommended to be used with a tripod; yet quick, informal views can be relatively easy to accomplish hand held, especially while grasping it by the objective ends. The lenses are situated deeper on the front end than the 15x70, possibly suggesting a type of dew/sun shade purpose. Other differences to keep in mind in comparison with the 15x70 include the smaller observational field of view (of course) and the merely point and look aspect of the smaller bino is diminished in the 25x70 (of course) with the greater magnification coupled with that narrower field. These are just part of the game and should be of no surprise. With more use, I am inclined to suggest this may become my preferred set at first use. BTW, my 20x80's, apart from increased weight, are hardly used at home due to light pollution. Its larger objectives, at 80mm, bring in more light so are reserved for observation under darker skies. It was because of this suburban atmospheric limitation that I sought an alternative for increased magnification beyond the 15x70 and settled on the 25x70.