1.Introduction
Today I am pleased to present to you my latest creation - a pair of ultra-wide angle 4.6x 30 binoculars with Afov of 100°, Tfov of 21.7°, EP6.5mm, and a weight of approximately 2.5kg. These Spacewalking binoculars have come a long way since their first generation and are now in their fourth generation. Over 4 enthusiasts in China have been working closely to advance this amazing project, and by the end of 2024, we aim to finalize the design for the 5th generation.
2.Specs at a glance
Aperture:30mm.
Magnifications:4.6x.
Apparent field of view:100°.
True field of view:21.7°.
Weight:2.5kg.
Demesion:280mm×130mm×87mm.
3.From idea to reality
A few years ago, while stargazing with my son in the suburbs, he asked me a question that sparked an idea within me. He wondered what it would be like to be in space, getting closer to the stars and looking around. This made me realize that we needed a new type of binoculars - one that provided the most beautiful image, a wider field of view, and a immersive sensation as if you were jumping right into the space you see before your eyes. Unfortunately, such binoculars were not available in the market, so I decided to take matters into my own hands and build one by myself.
4.Story behind
In early 2023, the Spacewalking binocular had reached its fourth generation. However, the first generation was the most challenging as it required starting from scratch. The very first prototype(3.8x35) had a magnification of 3.8x with a 26° Tfov, consisted mainly of Ethos 13mm eyepieces and Nikon ASI 50/1.4 lenses. It took me six months to design, purchase and construct it upon completion.
In the second generation, 2047 Studio helped me addressed the mechanical and durability problems of the central column, resulting in better image merging. The 3rd generation was a giant leap foward. Because the stars in the Nikon lenses looked like a sea urchin when looking throught it, thus, an alternative was sought. And eventually, the Schneider Super-Cinelux 60mm lens had replaced the Nikon. The upgraded lenses offered a much better image with pinpoint stars and an overall better appearance.
Mr Zeng's ingenious idea to incorporate an Amici prism in front of the objective lens was a groundbreaking innovation that energized me to put my maximum effort to the 4th generation. Bimuniu, a pro optical designer in China, sent me his latest Amici prism for testing, and his product proved my concerns about prism transmission unnecessary. However, there was a critical issue. Every time you made inter-pupil adjustments , the binocular collimations would be lost, and it had to be collimated manually again and over again, which was a fatal flaw. Hence, I am proud to announce the forthcoming 5th generation, where all issues will be resolved. The preliminary design for the 5th generation is now completed, and 2047 Studio has taken over the remaining work in progress. Additionally, I am consistently refining the previous versions as I have got more spare time to upgrade them. Please refer to the attached photos. Figure 1 is first-generation, figure 2 is second-generation, and Figure 3 is the third generation, Figure 4 is fourth generation, Figure 5 is 5th 3D model rendering.
5.Characteristics
Spacewalking binocular is ideal for outdoor activities like observing landscape, birdwatching in the daytime, or Stargazing in the nighttime. It provides excellent optics with crisp stunning view, making it as sharp, translucent, flat, low CA, contrasty as a pair of Swarovski. Thanks to the 100°Afov and huge depth of view, from 5 meters away to infinity, you don't have to refocus at all. When you go out for stargazing with these binoculars, a feeling of immersivness surges through you as if you were travelling into space. Perfect rounded stars, even on Jupiter or the brightest stars, 80% pin point stars in field of view are guaranteed( field is flatter than Swarovski, equivalent to Nikon WX) . I am glad I 'd realized it and my son's dream came true.
6.Observation experiences
Before the 3rd generation, the view through binoculars was inverted. This means that when you looked through them, closer objects appeared farther away and vice versa. This created a fascinating sensation for the viewer, especially when stargazing, as it made stars appear closer and within reach. This special sensation is why I plan on keeping one of the 3rd generation binoculars. Here are some of the observation experiences to share:
(1)Endless immersiveness. Owe to thinner barrel of Eye lens, stars in＆out of field of view had merged into one, a true feeling of space walking. Mr Zhang Wuzhou was quoted as saying :" it feels like there was no lens at all between you and stars, you were in space, nothing could compare with it favourably". "it's like watching a pair of bino-nightvision with colossal Fov, and it deserved more attention".
(2)21.7° Tfov is meant to fit everthing into it easily,Orion, Auriga,Cygnus, Gemini, Cassiopeia etc. Orion is looking crystal clear , and you can some pick up open clusters in Auriga as well.
(3)Sweeping the Milky Way ,contrast between bright areas and dark patches is visible in background, kind of like fluffy cloud. No conventional optics like Skyrover constellation bino or Swarovsky SLC 8x56 can really come close to competing with it.
(4)Challenging M81&M82, is visible but subtle.
Professor Mok, an experienced observer from Macau, describes Spacewalking bino as an unique, ultra wide binocular he has been chasing once in a lifetime. And he said: "you can't see the forest for the trees is utterly avoidable using Spacewalking binoculars".
7.Conclusion
To summarize, I would describe Spacewalking binoculars as having a 3-5x power, a 20° Tfov or greater, and an diameter of 6mm exit pupil. However, achieving these specifications is tough due to two main factors. Firstly, a large 6mm exit pupil requires a larger and faster lens with a F-ratio around F/2.0. Additionally, finding high-quality lenses that are transparent, sharp, saturated and have a flat field can be very demanding of your time. While I have tried several excellent lenses, I have only found a few that meet these criteria, and they are both rare and expensive. I recommend considering Schneider and ISCO projection lenses, but it's essential to test them to ensure they are in focus with the eyepieces. Secondly, there is only a few millimeters of space between the objective lens and the eyepiece, leaving no room for a traditional erect prism. Fortunately, Mr Zeng's innovative idea has successfully accomplished this.
I am planning to use the Schneider Super-Cinelux 80mm lenses along with the XWA20, Ethos17, Ethos13, and Ethos8 eyepieces for my project. These eyepieces offer an impressive apparent field of view of 100° and can be used for anyone with a interpupillary distance greater than 63mm. It will come in four available specs (4.0×40, 4.7×40, 6.2×40, 10×40) and can be used as replacements for MK43 and Nikon WX. When combined with low-power, ultra-wide, and large exit pupil, these optics really push the boundaries of the industry." Welcome everyone to make this special binocular together.
8.Acknowledgments
The team behind the Spacewalking binocular are all optics enthusiasts from Chinese astro-communities. I am Rogan Yue from Beijing, the first one to design and construct Spacewalking binos, and soon more teammates joined in. I'd thank 2047 Studio, Mr Zeng, Mr Bimuyu, Prof Mok for their huge support to the project, and Spacewalking binocular wouldn't be possible without their contribution. I also welcome friends from all over world to join us, carrying Spacewalking binoculars foward.
Rogan Yue, 2024-3
Beijing, China
