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Garrett Optical 25x100 IF Binoculars

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About me

I’ve been observing in my home area of Virginia for about 5 years. Over the years I’ve owned a Celestron C90, an Orion Xt8, an Orion Xt12i, a Celestron C102 short tube, a Stellarvue 115mm APO, and a 10” Teleport. More recently I’ve been doing a fair amount of binocular observing using (at first) various Marine binoculars (from my other expensive hobby) then some Meade Travelviews, an Oberwerk 15x70, and most recently I’ve had the urge for something a bit bigger. This review describes my experience in acquiring and using a Garrett Optical Gemini 25x100 IF binocular. I have no connection with Garrett Optical other than the contact described in this review.

Why 100mm?

I already had a nice pair of 15x70 Obies, a 100mm short tube refractor and a big 12” dob. I had sold off a larger refractor and EQ mount because they were too complex for travel and were beat out by my dob for “at home” viewing. So why add the 100mm binoculars? I like the simplicity of my Obies – no decisions to make on eyepieces, no left-right reversal of image - and straight through viewing just seemed to connect me more with the night sky. I kept the Obies on a monopod – they seemed too small to warrant the complexity of a tripod and fluid head. But I wanted to try some “serious” tripod based observing with the same simplicity as the Obies. 20x80 seemed too small a step up and there was a nice selection of 25x100s on the market. So it was time for the “big glass” and I just needed to decide which one.

Why the Garretts?

The 25x100mm market seems to fall into a few categories. At the least expensive end there are the brands that seem to be based on the frame most often marketed as the Celestron Skymasters. The Celestrons come with a robust lifetime warranty; the other variants like Barska and Fotar seem to be trying to establish themselves as the low price leader. These are typically sold for anywhere from $175 to about $300. Many people swear by them and there’s no denying the value. There do seem to be quality control issues with these; there are many stories of having to return 2 or 3 defective pairs before getting an acceptable one and I didn’t want the worry or the hassle.

I tend to think of the next tier up as the Oberwerk tier. Oberwerks are retailed in the US by Kevin Busarow at BigBinoculars.com. Kevin and Oberwerk have established themselves as quality suppliers with a reputation for outstanding customer service. Their 25x100 IF has been favorably reviewed many times. Similar looking binoculars have also started to appear under other brands like the Anttler “Skysweepers” (their 20x80 LW got a positive review in CN) and, in the fall of 2005, by Zach Garrett as the “Garrett Optical Gemini 25x100 IF”. The Garretts "appeared" to be identical to the Oberwerks (and by appearance I mean every specification I could find as well as reports from users) and the Garrett 20x80 triplet was reviewed and rated the equal of the similar model by Oberwerk. At the time I bought them, Garrett was new and trying to get a foothold in the market – they were discounting their products and offering them on ebay at auction with low starting prices. I "won" them at auction on eBay for $300 (plus $30 shipping) which, at the time, was $110 less than the Oberwerks (the price gap is closer to $20 today). Zach Garrett seemed as committed to quality as Kevin Busarow is, and Cory Suddarth, Garrett’s resident optician, has a reputation for optical expertise that’s as good as it gets.

The next tier up in the 100mm market seems to be a big jump. There are the Obie BT100s and the rest are premium Japanese or German optics. Pretty as all of these might be, they are simply out of my price range.

Technical Specifications (copied from www.garrettoptical.com)




100mm f/4.5; 2 Elements, 2 Groups


4 Elements, 3 Groups




16mm useable (18mm total)






2.4º (126 ft./1000 yds.)


10 lbs., 0 oz.




Fully Broadband Multi-Coated


99.0%-99.7% per surface; >85% total


Yes, for up to 5 min. at 1m depth



First Impressions

When I ordered the 25x100s, I sent Zach Garrett a note explaining my expectations and what I hoped he or his staff would check out before shipping. Zach replied with reassurance that everything I asked about (and lots more) would be checked out as part of their “normal QC procedure” and guaranteed by him personally. I like being able to have that kind of conversation with a knowledgeable business person who has a vested interest in his product and his firm.

They were shipped about 36 hours after ordering and arrived 5 days later. They arrived in triple layers of packaging - a box filled with "peanuts" around another box which contained a bubble wrapped aluminum case which contained the binoculars packed in plastic and form fit foam. I seemed to be unwrapping forever – it was like Christmas.

Once out of their packaging I got a chance to inspect them. The overall level of fit and finish was very high. The rubber armor was perfectly smooth and pleasant to the touch. The hinge for adjusting the IPD was stiff but solid and smooth. The focusers moved with precision – there was a hint of “stiction” but once moving they were smooth, easy to adjust, and quiet with no “grainy” sounds I hear in some of my other binoculars. Peering down the objective barrels in various lights showed even and deep colored multicoating with hints of green and purple; reflections were minimal. From the eyepiece end, the coatings seemed equally effective and the exit pupils appeared sharp edged and perfectly round. The hinged eyepiece cap is a terrific improvement over anything else I’ve used. The objective covers are rubber and fit inside the objective barrels with a lip that extends over the outside edge.


When I ordered the binoculars I’d also ordered a one inch extension post from ScopeStuff (part #BINX) since I’d been warned from reviewers that the center mounting post was simply too short. The binoculars, the extension post and the tripod mounting plate came together easily. Mounted on my Amvona AT-6907 (a Bogen 475/501 clone) they looked impressive - like some great glassy eyed bug - and seemed steady enough. Adjustments damped out quickly as did accidental bumps.

The mounting post has ¼-20 threads as does the Scopestuff adapter as does the tripod’s quick release mounting plate. The quick release plate will also take a 3/8” captive screw and I’d have preferred that the binoculars and adapter used the larger threads. Hanging ten pounds of precision (and expensive) optical equipment on a ¼” bolt doesn’t feel right and, in my opinion, is a weak spot. I plan on drilling out and re-threading both in the near future.

When mounting these, it’s important that you balance them for your own observing tastes. This is the first pair of binoculars I’ve owned with a mounting post and I immediately adjusted the post position so that they were balanced horizontally on the post. This turns out to be a mistake for astronomical use and, I’ve since learned, it’s a mistake that many people make. Anytime the binoculars were elevated to any angle they "wanted" to keep climbing - the Center of Gravity (CG) shifts back with elevation and the imbalance gets greater with increased elevation. There’s no way to avoid this with a traditional tripod setup – the CG is not on the axis of rotation as it is on, say, a Helix Alt-Az mount – but there is a way to minimize its impact on your observing. The binoculars should be mounted on the tripod and then adjusted to balance at an elevation angle that is about halfway through your typical range of use. I have lots of viewing obstacles in my neighborhood so I rarely drop below 30 degrees and I'm often close to 90. I adjusted the position on the post so that it would balance (with no tension on the elevation knob) at about 60 degrees of elevation. That means at horizontal it's inclined to sag toward the ground but it also means that it takes very little effort to control through most of the useful range.

First Light

The first night offered only a little bit of clear sky. It was about 0°C and the wind was blowing my whole setup pretty hard when I started putting it through its paces. The first thing I noticed - this is a whole different beast from my 15x70s. It took a lot of effort to set and control the elevation (this was before I’d rebalanced them as described above). And it was hard to find things – sighting over the top of the binoculars just didn’t give me enough perspective to readily find even bright objects easily. Remember this is only a 2.4 degree Field of View.

With that wind blowing, stability matters and my setup felt pretty stable. Even with the center column cranked way up, the 10 pounds of weight seemed to damp out a lot of vibration. One scary moment – the wind blew the binoculars hard enough to cause them to unwind half a turn from the mounting plate. Seeing them turning by themselves with the objectives swinging toward the ground was enough to get the adrenalin pumping. I’ve since added a bit of loctite between the post and extension and some rubber cement between the extension and the tripod plate – the friction contact alone just isn’t secure enough.

These problems aside, in an hour of viewing I saw some beautiful sights – and keep in mind that this is in well lit suburban skies. M36 and M38 showed lots of stars – not something I’d seen before (in my local skies) with my 15x70s. M42 had its well known shape and appeared wispy and delicate and M43 showed some faint nebular glow. The trapezium was actually separable into three and sometimes four components. I did a quick turn through the Pleiades, the Beehive – both impressive but actually better framed in the 15x70s. Saturn’s rings were clearly separated from the planet – but there is a bit of flaring that distracts from the view.

I came away from that first night with a mixed impression – more work, harder to use, better views.

First Week

In the first week I managed to get out four times and my impressions steadily improved. Once I rebalanced the binoculars at 60 degrees it became much easier to manipulate and control them. I also added the second arm that came with my mount’s head and reversed them so they were pointing away from me – I’m not sure why this seems better but it does (at least for me).

My ability to sight directly to bright objects improved but was still challenging. I actually sight along each barrel from the top with only one eye and then along the side of the barrel – it works, but it’s time consuming.

On my second night out - with better skies - I carefully adjusted the focus. This is the first binocular I’ve owned with individual focusers and I found using them intuitively easier than the center focuser/right diopter adjustment that I’m used to. Both focusers were smooth and easy to adjust. I then went through two sessions over the next two days without touching the focusers - they held focus through break down and set up twice and I just didn’t need to adjust them.

I keep the binoculars set up on the tripod in my garage. When I head outside I just pick them up extend and lock each leg, remove the covers and start – the whole process takes less than a minute. Breakdown is just as easy and quick.

I started to become a bit more methodical in my observing and went after objects that I hadn’t been able to find before. I hunted down a bunch of galaxies in the Virgo cluster (just smudges but very visible) and then revisited objects that I’d only before found with much work - galaxies M81 and M82 were easier to find, brighter, and M82 showed some elongation and definition and both showed brightness at the core. Star hopping with this is just a pleasure using a Sky Atlas 2000. The field of view is big enough to make star hopping easy and bright and contrasty enough to use even very dim stars as guideposts – I found myself puzzling over asterisms that were not visible in my SA2000 simply because they were too dim to be shown.

I stayed out late one night and got to admire the color and clean separation of Albireo and the many double and triples in the Lyra/Cygnus constellations. The Ring Nebula in Lyra was readily visible with brightness on the outer ring but no star at the center.

To me, the Garretts seem sharp all the way to the edges left to right in the FOV with only the smallest bit of blurring and darkening at the extreme edges. But I noticed that the top of the FOV seemed to elongate stars vertically and the bottom seemed to (very slightly) elongate them horizontally. At first I noticed only the elongation at the top and I thought it might be an off axis sharpness issue but the bottom distortion seemed to suggest something else. I exchanged emails with Zach Garrett about this and he seemed genuinely puzzled – he had checked these out himself and didn’t notice anything like that. I tried experimenting with different viewing angles and different eye positions and could often eliminate the distortion. I also compared them with my other binoculars and could now see similar distortion in those instruments. I’ve tentatively concluded that this is an artifact of either my eyes or of how I observe. It doesn’t detract from my viewing and I’m continuing to experiment with new observing behaviors to minimize or eliminate it. I do not believe it is a characteristic of the Garrett optics – this is just the first time I’ve routinely observed through tripod mounted binoculars.

The optics do show some CA on bright objects perhaps most noticeable on lunar observation. Planets and very bright stars exhibit flaring making the view a bit frustrating – I’m always trying to shift my eyes to eliminate the flaring and it often shifts from one eye to the other. Ah well – that’s really not what these are for and it’s why I have my small refractor.

First Month

I've now been using the Garretts for almost a month and I'm more impressed by them everyday. After two weeks of using them I added an index finder (a Burgess MRF) and at that point I just stopped noticing them; nothing about them distracted me from the viewing which is what this is all about. Aiming them is now trivially easy and, once at my starting point, my ability to star hop in bigger hops is improving all the time. The whole setup feels like a natural extension of my ability to see.

I haven’t measured the FOV, but I use charts with a 2.4 degree circle drawn around my targets and the views seem the same in the Garretts – I have no reason to think they are any more or less than claimed. And the brightness, contrast and sharpness of the FOV is more than adequate across the whole field to make star-hopping easy.

Similarly, I haven’t measured the eye relief, but I’m able to observe comfortably with and without my glasses. I rarely use glasses when observing but sometimes I forget to remove them when I switch from chart to eyepiece. Sometimes I notice them and other times I don’t – which to me means the eye relief is adequate.

The Garretts have become my observing instrument of choice. I still use my handhelds (8x42 that are always within easy reach) and my 15x70s (always in my car with the monopod for quick stops on the road). If I’m at home I’ll often have the big dob out along with the Garretts for better views of some DSOs - there’s nothing like seeing M13 in a big dob. But the best is tossing (figuratively) the Garretts in the back of the car (maybe along with my small refractor) and driving out to dark skies. It’s here that the Garretts really shine and you can start to appreciate the difference that the additional aperture and magnification give you.

Under Dark Skies

Out in Delaplane Virginia, the skies are quite a bit darker than at home. I’d been doing some practicing for the Messier Marathon and, using only the Garretts, I was able to run a list of 21 Messier objects in less than an hour. Started with the easy ones M45, M42, M43, and, as the sky darkened, moved along to the Auriga clusters, the Crab, M78 in Orion, the clusters of Canis Major and Pupis, and ending on the Galaxies M81, M82 – both strikingly visible as galaxies instead of the elongated smudges I see from my home skies. This was an unhurried pace – I got to pause and admire each of these and spent some time with averted vision counting stars in M36 and M46, and I spent a long time admiring the M81/M82 pair. These are all relatively easy objects to find and I’d found them all at home as well – there was just a lot more to see out here. Once again, the focusers might have been tweaked just a bit (or not – I honestly can’t remember) but they’re normally untouched in these sessions.

Two hours later I was able to run the 16 Messiers in the Virgo galaxy cluster in less than an hour. Starting with a visual on Vindemaitrix and using the B1 insert in the Sky Atlas 2000, I was able to “circle hop” the images in the FOV to quickly cover the territory between objects. The index finder allowed for an easy visual jump to Chertan in Leo and in ten more minutes I’d added the five galaxies in Leo to my check list. Unlike the previous list, I’d only seen about half of these at home and they only looked like the faintest of smudges. Here, these were clearly galaxies with definition, shape, and varying brightness.

I don’t normally race around the sky like this – but a Messier Marathon is just that. The combination of the Garrett’s great imagery and focusers, the steady mount, and the index finder made this an enjoyable relaxed tour instead of the frantic and uncertain pressure cooker it can sometimes be.


The Garrett Optical Gemini 25x100s are the real thing. They give great views of stars, clusters, Galaxies and Nebulae. They exhibit a very high quality of build and Zach Garrett inspires confidence in his readiness to stand by his product. They’re not for Lunar or Planetary observing – they’ll do an OK job there, but the color (Chromatic Abberation) on the moon and the flaring on bright objects like planets will prove distracting. If you decide to acquire these make sure you’ve got a mount that will easily handle the ten pounds, do take the time to balance them correctly, and seriously consider adding an index finder. So configured and equipped, they will provide outstanding and memorable tours of the night sky.


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