William Optics 1.25" Binoviewer Package (with 1.25" Wide Angle Eyepieces and 1.6x Barlow)

Bought this for use with an Orion XT8 Plus newtonian reflector. The William binoviewers are a solid, high quality piece. And the two 20mm lenses are excellent. Came in a custom cut-foam box. I'm very impressed with the entire kit. All the components are top notch. Binoviewers appear to be in good collimation, and the individual eyepiece focusers and the hinge for adjusting eye separation are both smooth and with sufficient friction to easily hold adjustment.There are caveats with using bonoviewers with a newtonian telescope, but the benefits of seeing with both eyes is so great that I thought it would be worth figuring out a way to make it work. And it is. I'll explain one way to get it working with the XT8, as well as some limitations.Because the binoviewers move the eyepieces so far aft of the usual focal point (because they extend out of the focuser and have an even longer, bent light path), it was not possible to attain focus on the XT8. There is not enough inward travel on the focuser. The solution is to use a barlow. At first I used the included 1.6x barlow from the WO binoviewer kit. But it was not strong enough to allow focus. So, I tried the Orion Shorty 2x barlow that comes with the XT8 Plus, and that worked. But what is even better is unscrewing the lens section from the barlow (the short piece at the end; the rest is just an open tube extension) and screwing it onto the binoviewers directly. With this, I was able to attain excellent focus.Once working with the XT8, the binoviewers rewarded with breathtaking, seemingly stereoscopic views. The brain wants to use both eyes, and it integrates the two inputs into an image that simply can't be emulated with a single eye and eyepiece, regardless of optics quality. The image can't really be stereoscopic -- because it is coming from a single input -- but it looks it anyway. If you've ever used astronomical binoculars (which also can't really be stereoscopic when looking at astronomical objects because the eye separation is irrelevant compared to the distance to the object) you will know the feeling. It's much easier to observe for long periods of time. I just relaxed and stared, no squinting. Mountain ranges at the edge of shadows on the moon were amazingly 3D. Orion nebula was nice, too, but seeing was lousy (haze, and I live in the LA area, so light pollution). But this is not the binoviewers fault.Downside is that the magnification using the barlow is even greater than 2x due to the long extension from the binoviewer. I'm thinking 3-4x. And there will be a limit on how big of eyepieces you can use to compensate due to the diameter of the light path through the binoviewers. The included eyepieces are 20mm, but I doubt you can go much over that, maybe 25mm? Hope I'm wrong, that is just a guess. Won't know until I try, and I'll have to buy or borrow some eyepieces to give it a go since I don't own any eyepieces greater than 20mm in 1.25-in dia. All my low power eyepieces are 2-in.My goal is to get the binovewers working with the 1.6x barlow. The fix is to place screw-on extensions between the barlow lens-cell and the binoviewer, without extending the binoviewer any further out of the focuser. So the stack needs to screw on to the binoviewer and extend down into the focuser. I tried stacking a couple of filters (~0.5-in) in front of the 1.6x barlow, and *almost* achieved focus. The magnification was clearly *much* less than when using the 2x barlow. It might actually be 1.6x because the barlow is designed to deliver that magnification when using the binoviewers, whereas the Orion 2x barlow provides 2x magnification over a shorter length, and 3-4x when working in front of the binoviewer. Going to buy a couple of short 1.25-in dia screw-on tube extensions to move the 1.6x barlow a bit further down the focuser tube, and that should do it. Hope for no vignetting.Anyway, IMHO every telescope should have binoviewers for doing eye observations. There is no comparison between it an a single eyepiece view. The brain want to use both eyes, and some grey-matter processing is going on that delivers dimensionality and characteristics to the image that don't exist in a single-eye image.I'm totally happy with these from both a quality and function standpoint, even though I'm using them for a telescope type they are not intended for. Getting such things to work is part of the hobby.

Pound for pound, weighing these binoviewers against other more expensive ones has showed me that these are a great economical choice. Why? Your looking at pair of binoviewers that cost 1/4 or less of the price for an expensive pair. They perform just the same, with the exception of a smaller prism and other asthestic and operational shortcomings. I measured the prism size at 25mm, with the internal barrel "feild stop" being at ~23mm. So in theory, you could machine out the feild stop to marginally increase light intake. There are some minor flaws I will point out near the end of this review. To be fair, these binoviewers do cut light, but in large telescope apertures 200mm or more, the difference is very slight, depending whether or not your using the included barlow lens. The eyepieces work great in some of my faster scopes, f/4 to f/6. One night I tried a single 19mm Panoptic and ended up getting a pair of them for these binoviewers. The panoptics correction makes stars tack sharp with the binoviewers and enables me to use them on faint DSOs. So if you notice a blurring effect, it's not the binoviewers, it's the 20mm WA eyepieces. Yes I could have purchased a TeleVue Bino for the combined money, but in larger telescope apertures only marginal light reduction differences between the two become apparent. That being said in smaller aperture telescopes theTeleVue binoviewers blow these away. So deciding to buy the WO binoviewers is dependent on what your going to,use them for and how big your telescope aperture is. For planetary and double stars/clusters, these binoviewers are great. They will work on most DSOs provided you use them in a large aperature telescopes. There are a few flaws. The diopter adjustments have no markings. I find this irritating when I have friends looking through, and not knowing what their numbers are, so getting good focus takes up a bit of time. The diopter locking screws interfere with each other if the interpupillary distance is close. It is difficult to use most heater strips because of the locking screws. So that sums up some minor issues. As for the collimation, mine arrived dead on. All the glass is fully multi-coated. There are coating differences between the prisms for each eyepiece. I'm not sure why though. I will point out though that William Optics intentionally set out to produce an affordable binoviewer option for most amateur astronomers without cutting too many corners, and they did a good job at that. If your looking for a planetary binoviewer or have a large aperture telescope, this is a great option. For small telescopes below 200mm I would reccomend a binoviewer with a larger prism.Update: I have to say that I was initially overzealous about these binoviewers when I gave them a three star rating. They really are good quality binoviewers. I mean they definately could use some improvements for the money bieng asked for them. But after using them for a while now I'm now giving them a four star rating since these binoviewers have always given me good and consistent results.

I'm new to binoviewing and chose these W.O. Binos for my latest 127mm F9.4 achromat. The W.O. are in the low price range and have a restrictive field stop due to smaller prisms. I understand that you can't go much wider than the supplied 20mm eyepieces before vignetting sets in. They hit their price point by restricting prism size and field stop. But that price point is a sweet spot in the market and these are really nice instruments! I'm amazed what I got for this price. The eyepieces alone should be worth the total price. Then you get a very well made binoviewer and 1.6 barlow to make it work with most scopes. Last night I went to my club field to photograph Comet Lovejoy, A waxing crescent still had a few hours to set so I put in these W.O. Binoviewers without the barlow to have a look. My homemade telescope has a generous 3" diameter draw tube so reaching focus was no issue at all. It took a few minutes to focus each eyepiece separately then a little fiddling to get the pupillary distance correct. It was then I experienced what they call "merge". The moon snapped into super sharp focus, it was three dimensional and strikingly beautiful. My eyes (and brain) relaxed. I grabbed a chair and spent a lot longer just looking at every detail than I would ever with a single eyepiece. I like photographing the moon but I've never spent so much time just looking at it! Later, I examined M42 with these and had a similar experience. Binos are a must have for the visual observer and these William Optics are really good at their price point.