Why do I need image stabilsation? There are a few reasons why you might want to consider image stabilised binoculars and spotting scopes.  Minimising hand movements or shakes plus improving the view First of all, as you increase the magnification of binoculars, not only does the size of the view get magnified, but also any hand movements or shakes. Everyone has some degree of hand shakes when using binoculars and while adjusting the way you position your arms and body, this is not something that will improve as the years go by. <sigh> If you find the time spent in the field, particularly when you're out birding, is becoming more demanding, then image stabilised binoculars might be a way to help avoid this.  There are many situations where higher magnifications really bring out the best views as well. Taking in details in distant scenery or close up observations of nesting birds are two examples. The other thing to consider is that our mind spends more time removing the "jiggles" and less enjoying the view.  What you see from image stabilised binos not only appears still, but also much brighter and sharper. Less tiring for extended viewing Even at "regular" magnifications such as 8x or 10x, you will start to tire during long observing sessions while you concentrate on the view. Removing the need to pay attention to holding your binoculars still move will make these sessions more relaxing and enjoyable.  Not exactly new Image stabilisation binoculars are not new and have been around for a while. There were models from Canon that went back to the late 90s and ones from Fujinon that were from about the same era.  Originally stabilised binoculars were popular for marine use and helped solve the problem of an unsteady platform beneath your feet and everything around you moving by using mechanical movement of the lenses to correct for shakes. These worked, but weren't especially compact. There were also some limitations on the optical capabilities of these earlier stabilised binos compared to other non-stabilised models. (I'll make a special mention of the ZEISS 20x60 T*S Image Stabilised Binoculars which are a purely mechanical design, masterful optics and super rugged.  The most expensive binos we've ever sold! They even use them on the International Space Station! Full details here.) Recent developments  The move over the last few years has been away from binoculars that move their lenses to keep the view steady to ones that use sensitive gyro sensors to subtly and quickly adjust their internal optical paths.  By quickly responding to movements detected by small, fast acting sensors, recent image stabilised binoculars  offer buttery smooth damping of shakes and bumps. These now offer at least two to three times the correction of older models.  Diagram showing how Fujinon's gyro stabilised binoculars work The more recent miniaturization of the stabilising system have not only made them fast and more accurate, it's also reduced the size of the binoculars as well to the point where they're not dramatically larger than non shake reducing models. This is very important if you're out birdwatching or travelling.  As their main lenses are always kept in alignment, the quality of the optics are now right up there with traditional binoculars. This was something older models struggled with slightly.  More compact mechanisms. As manufacturers further miniaturised the stabilisation systems, they were able to add the technology to even  25mm sized binos.   What model is best for me? Here's some of the popular image stabilised binoculars available from BINTEL Compact viewing options. Nikon STABILISED 10x25 and 12x25 These image stabilised binoculars are small enough to go anywhere with you while making long observations as comfortable as possible.  These are tiny, foldable image stabilised binos. They weigh only about 460g even with batteries and fold up into a tiny package.  The newer generation Nikon STABILISED binos are not much larger or heavier than regular binos of the same optical specification. Ideal for bird watchers after portable binoculars that are conformable to use for extended periods.    Nikon STABILIZED 12x25 S Binoculars Kenko VC Cellarto 10X30 Stabilised Binoculars WP Another range of compact image stabilised binos are the Kenko VC Cellarto. These offer about 28 hours of use from a single AA battery. Kenko VC Cellarto 10X30 Stabilised Binoculars WP Kenko have incorporated a dual mode system.  They steady the view if you're making long, sweeping movements for example when searching for birds or other wildlife and then automatically switch to another mode to minimize hand movements when you've found your critter and are now viewing it for an extended session. They're well priced and have a higher powered 15x42 model as well.  Higher end options.  The two premium line ups worth looking at are from Kite Optics and Fujinon Fujinon TECHNO-STABI  Fujinon are one of the pioneers of image stabilised binos and their latest models continue this tradition.  TECHNO-STABI models have correction ranges from ±3° in the compact models right up to ±6° in the flagship TS-X 1440. These high correction rates make them a great choice for anyone heading out on the water.  The compact TS 12x28 has been popular with our BINTEL customers.  It runs up to 30 hours on a single CR2 battery   Fujinon TECHNO-STABI Binoculars TS 16x28 The larger TS-X 1440 (14x40) adds the full ±6° correction range and a buoyant, water-resistant chassis. This means that if the go overboard, they float. No need to go diving in to retrieve them! Fujinon TS-X1440 TECHNO-STABI Binoculars The new Fujinon TS-L series have 16-x40 and 20x40 models, both with ED (Extra-low Dispersion) glass for ultra sharp views.  They weigh around 850g, which makes them very manageable for use in the field.  Kite Optics APC Kite have been big hit with our birding customers as they make large high quality binos that have remarkable image stabilisation capabilities.  Their optics are also right up there with non-stabilised offerings from premium optical companies. Kite Optics binos are made in Japan, with final testing at their head office in Belgium. They've also nailed the power side of things as well. Both AA-battery and Lithium-Ion options are available.  It's sealed to IPX7 waterproofing so no dramas if you get caught in a heavy sudden downpour.  Check out the full Kite Optics range here.  Kite Optics APC Stabilized 18x50 ED Binocular (Li-ion) Kite Optics also have small and interesting new gizmo, the Kite Optics STABI ONE 10x20 Stabilised Monocular. This provides a tiny 10x20 monocular that is about as "go anywhere" as any optics could be. It runs off a single AAA battery that lasts for months.  An interesting accessory is a phone attachment allowing it to greatly add to the photographic abilities of your phone while taking up very little space. Basically, a telephoto phone lens with rock-steady views.  Kite Optics STABI ONE 10x20 Stabilised Monocular Image stabilised spotting scopes While image stabilised binoculars have made binoculars much easier and more comfortable to use, the image stabilising tech that has been introduced to spotting scopes recently has radically changed how these optics are use and added new options for those heading out to observe wildlife.  Traditionally spotting scopes have needed tripods as with their much higher magnifications, humans must use a tripod with them as we can't hold them still.  By removing the need for tripods, you're now able to use high power spotting optics without having to carry and setup a tripod.  The Kite APC 60ED with 17-35x magnification was the first to offer these features and caused a lot of interest from our customers.  Complete with rechargeable battery it weighs just 1300g.  Kite Optics APC Stabilised 60 ED Spotting Scope Recently the Swarovski AT/ST Balance were the first of the traditional leading European optical companies to get into the stabilisation market. Their two models, AT Balance (angled, 18-45x65) and ST Balance (straight, 14-35x50), bring the renowned Swarovski optical quality and a new SWAROBALANCE stabilisation system, which measures movement more than a thousand times per second for a super smooth damping of any hand movement.  Having tried these out in person, these new Swarovski image stabilised spotting scopes are almost uncanny in the views they produce. Your mind essentially says to you "this can't be real!" Swarovski AT Balance 18-45x65 Can I use image stabilised binoculars without the stabilisation? Yes.  They'll behave like normal binoculars of the same optical size if you switch it off or the batteries are flat. Image stabilised spotting scopes can still be used, although you will need to put them on a tripod to hold them steady. Downsides? There's two mainly. First of all, due to the inclusion of electronics and batteries, they will be slightly heavier than normal binoculars. They will also be more expensive.  Bottom line Image stabilising technology has spread from specialised, large binoculars in recent years to smaller and more capable optics. It's gone from something that holds binos steady when out boating to an option for many birders and nature viewers. The new image stabilised spotting scopes have opened up a new way of viewing and exploring nature.  We're always happy to chat with you about the best options to suit your interest and lifestyle! Cheers, Earl White BINTEL 17th July 2026      

JWST Marks 4 years of stunning images and tantalizing discoveries Time flies fast when you're observing the Universe!  Hard to believe that the James Webb Space Telescope (JWST) has been observing the Universe for four years. To mark the occasion, NASA has released new images of the galaxy, Centaurus A (NGC 5128). This is a spectacular galaxy that is a favorite of astronomers of all levels, and its dark dust lane can easily be seen even in small telescopes.  This is the result of two (or possibly more) galaxies colliding about 2 billion years ago. Centaurus A was first observed from Parramatta in Sydney's western suburbs a smidge over 200 years ago. (We celebrated this anniversary in a blog article in March.) This is how astronomers usually see Centaurus A from Earth: Image by Lefty Wright taken with a Celestron EdgeHD 8" and posted to the BINTEL Society Facebook Group here. You can see the stars in the centre of the galaxy is heavily obscured by the vast dust clouds.  In contrast, this is how Webb now allows individual stars to be resolved.  Webb’s infrared instruments can see through much of the obscuring material to reveal individual stars, nebulae and other structures towards the centre of the galaxy.  This is because the dust clouds that block large amounts of the visual light but is far more transparent to the infrared wavelengths picked up by Webb's instruments.  It's well worth exploring the full suite of images at the NASA site here.  NASA's New Horizons Spacecraft wakes up after a long snooze It's been in the news. It's a pretty routine procedure. The famous spacecraft that gave us close up views of Pluto is starting the next phase of its mission. You probably remember the amazing images of Pluto that the New Horizons probe sent back to us in 2015. Following its close encounter with Pluto and its moon, Charon and the extended period it took to transmit that data back to Earth, the mission was granted an extension. Where has New Horizons been? The first objective was a flyby of the Kuiper Belt object Arrokoth, which hadn't been discovered when New Horizons was launched in 2006. The close approach was in January 2019 and brought the spacecraft even closer than it had been to Pluto.   Arrokoth as seen from New Horizons in 2018 If you're asked what's the most distant object visited by a spacecraft from Earth, it's not Pluto nor did either of the Voyager probes encounter any outer Solar System bodies. It's in fact Arrokoth!  Following this flyby,  New Horizons carried out some observations of Proxima Centauri and other stars. In between these sorts of tasks New Horizons basically powers down into a hibernation mode to silently collect data while conserving power and resources.  On June the 23rd, flight controllers successfully "woke up" New Horizons following a 321 day deeps space snooze. It began transmitting data it had collected during this time. The spacecraft is 9.5 billion km from Earth and even at the speed of light, this data took nearly 9 hours to arrive back to its home planet.  New Horizons received a full health check and some software upgrades What's New Horizons going to do now? There's hopes for another encounter with a Kuiper belt object even further away from Arrokoth. The problem is that involves flying towards something that hasn't been discovered yet.  I had a chat with Dr. Alan Stern who is the principal investigator of the New Horizons mission to Pluto.  Essentially New Horizons is observing the outer edges of the Solar System while scanning the sky for possible to destinations. "We are currently doing outer heliosphere observations and awaiting a crossing of the heliosphere’s termination shock sometime in the next 5 or so years. We are also searching for a new flyby target using data from the Vera Rubin Observatory and preparing to make new KBO (Kuiper Belt Object) observations next year." he told me.  While the Voyager probes continue to function somewhat and continue to provide observation of deep space, the 1970s technology onboard doesn't have the capabilities of the more advanced New Horizons.   Major update now out for ZWO Seestar S30 Pro owners These tiny little telescopes keep getting more impressive ZWO released a major app and firmware update for their Seestar Smart Telescopes. Many of the new features are available for the Seestar S50 and S30 models, however the additional hardware in the Seestar S30 Pro telescope can take best advantage of this update.  Some of the additions that caught our eye include: Star trails Creates stills and videos to highlight the visual images of the star fields above your head.  Image via @astroman.au "One tap" Milky Way shooting This lets you easily plan and compose 180-degree Milky Way panoramas. "One tap" all-night planning Make plans to start and plan an all-night imaging session, even across multiple objects.  There's also been major feature updates to the Seestar image enhancement abilities and we're looking forward to the extended network control system. This will allow you to connect to and control multiple Seestar telescopes over a LAN.  These new features will be automatically available when you update your ZWO Seestar Apple iOS or Android app.  Saturn is in the morning sky for early risers The rings are slowly opening up as well Where Saturn will be in the sky around 5.00am on Sunday the 12th of July 2026 as seen from Sydney. Image via Stellarium Saturn has been climbing across the early morning sky, getting higher before dawn as it heads to visibility through the night from late September and October. The rings can now be more easily seen in even small telescopes.  There's also a nice gathering of Mars, Uranus and the Moon near the horizon. If you have a clear view to the north, it might even be worth having a crack at spotting the Andromeda Galaxy (M31) which will be very low.  This covers more sky than several full Moons, so you'll probably need binoculars to take in the entire galaxy.  Next SpaceX Starship flight this week. Lucky 13? The 13th test flight of SpaceX's massive Starship rocket is due to take place in the coming week. This is the another launch of the "V3" version and with each flight, it continues be closer to being major launch platform.  We'll likely have news of how the flight week went in next week's blog.  Keep an eye updates on the launch here.  Cheers, Earl White BINTEL 11th July 2026

The Vera C. Rubin Observatory starts an amazing project. The LSST is now underway! We've talked before about the Vera C. Rubin Observatory in Chile. This new telescope aims to image large parts of the southern sky every few nights in unprecedented detail.  After decades of planning and construction and years of testing and fine tuning, it has now started its main project. The largest survey of the southern sky, the Legacy Survey of Space and Time (LSST), is now underway.  During this 10-year project,  Rubin will constantly observe the entire southern sky every few nights to create an ultra-wide, ultra-high-definition time-lapse record of our Universe.  When running at full tilt, the 8.4 metre Rubin telescope will take a 3,200 mega pixel image every 40 seconds, allowing astronomers to keep an eye out for night-to-night changes. We used to think of the Universe as hardly ever changing, simply moving above us on a clockwork-like schedule. We now know that there are constant changes and Rubin might see up to seven million of these changes, or transient phenomena, every night. “Today, we begin filming the greatest cosmic movie ever made,” says Brian Stone, performing the duties of the NSF Director. “This moment reflects decades of vision, innovation, and the power of federal investment in science through the U.S. National Science Foundation and the Department of Energy. Every night, NSF–DOE Rubin Observatory will expand the frontiers of knowledge and strengthen America's global leadership in science and innovation.” Rubin will not just scan for changes in our galaxy and beyond, it will find stunning numbers of yet-undiscovered objects in the Solar System, cataloguing millions of asteroids and comets.  Read more here. The Milky Way is even larger than we thought Does this mean there's even more of our galaxy to image? Sadly, no..... XMM-Newton & Chandra revise distance to the outer spiral arms Sometimes when you're living in the middle of something, it can be hard to work out exactly what surrounds you. This is even more so when you're orbiting one of maybe 100-400 billion stars in the Milky Way. (The exact number is still unknown and this is just an estimate.) Even more confusing is that we're embedded deep in one of the arms of the Milky Way and our view of the far side of the galaxy is blocked by gas, dust and billions of stars. In fact there is some debate about how many arms the Milky Way actually has! Estimates about the Milky Way have been based on observing the way stars move and how the galaxy rotates. However this leave a lot of room for error. Astronomers are trying to change this by studying data from the studying X-ray data from ESA's XMM-Newton and NASA's Chandra observatories. They've noticed that explosions or gamma ray bursts (GRB) in other galaxies produce x-rays. “Instead, we did something new: we looked at the aftermath of three cosmic explosions that took place in far more distant galaxies. These explosions flung out X-rays that echoed through several of the Milky Way’s outer arms – and we measured the distances to these echoes directly.” said Beatrice Vaia of Istituto Nazionale di Astrofisica (INAF), Italy, who led the research as part of her PhD. By studying how these ring-shaped echoes slowly expanded over time, Beatrice and colleagues were able to pinpoint the distance of the scattering dust grains. As these lie in clouds within the arms of our galaxy, the team could directly measure the distance of the arms. Besides confirming the known distance to the Perseus arm, the scientists found that two of the Milky Way galaxy’s arms – Outer Scutum-Centaurus Arm and Outer Arm – lie up to 10% further away than we thought. Can I photograph the Outer Scutum-Centaurus Arm and Outer Arm? No, not really. They're heavily blocked stars and dust and can't be seen in visible light. Read more about the new size of the Milky Way here. Even more signs of possible life found on Mars Another pointer to past life, but again we can't say for certain life once existed on the Red Planet   NASA's Perseverance Rover. Image via NASA/JPL-Caltech/MSSS There's been a number of major announcements that hint at past life on Mars. The Mars Perseverance Rover (or "Percy" to its friends) has been exploring the Jezero crater since 2021, and one of the major mission objectives has been to look for signs of past life.  Now researchers have announced that the most complex organic molecules even detected on Mars have been found in a rock outcrop dubbed "Blue Angel". Samples collected in 2024 have been found to contain macromolecular carbon (MMC). These are large networks of carbon atoms which are often found in Earth rocks containing fossilized biological carbon and meteorites.  We're not sure exactly how these molecules were formed. Billions of years ago, a river channel carried water and sediment into Jezero crater. Fine-grained sediment settled to the bottom before eventually hardening into the mudstone rocks the team analysed. "While the specific formation mechanism of the MMC detected in the Bright Angel mudstones remains unknown, this is still one of the most exciting findings to date," said Ashley Murphy, a Planetary Science Institute postdoctoral researcher. What's even more tantalizing is this discovery of organic molecules at Jezero is over 3000km from the organics found by the Curiosity Rover and found close to the surface too. This means that whatever the mechanism that caused them, could have been widespread across Mars. Again, this is not an announcement of the discovery of life on Mars. Organic materials can be formed by non-biological processes and the rovers on Mars don't have the ability to directly look at samples to detect life. For life to be fully confirmed either astronauts need land on Mars or the samples left on the surface by Percy are collected and returned to Earth for analysis in labs here. Cheers, Earl White BINTEL 4th July 2026   

Comet 3I/ATLAS is older than the Solar System  NASA confirms our most recent visitor is 10 to 12 billion years old.  We've chatted before about the most recent visitor to our Solar System, interstellar comet 3I/ATLAS.  It's now on the way back into deep-space with possible a rendezvous with another star system many millions of years in the future.  Earlier this week researchers announced results suggesting it was formed much earlier in the history of the Milky Way.  By interrupting the planned observing schedule of the Webb Space Telescope, a team of astronomers used its NIRSpec instrument to observe 3I/ATLAS. These observations revealed exceptionally high levels of deuterium, about 30 times more than seen in Solar System comets. Deuterium is an isotope or type of hydrogen that has an extra neutron along with the normal proton.  These high levels of deuterium found on 3I/ATLAS points towards it being formed in a much colder part of the Milky Way. In addition, the comet would have been exposed to plenty of radiation, but not any long-term warmth that would have reprocessed its “heavy water” ice, with deuterium, into the type of H2O ice we are familiar with on Earth. Researchers used the NIRSpec (Near-Infrared Spectrograph) instrument on NASA’s James Webb Space Telescope to map specific chemical contents of comet 3I/ATLAS as it moved away from the Sun. Image via NASA, ESA. “This was a unique opportunity to study an ancient object from the distant galaxy, probably pre-dating our Sun and solar system,” said astro-chemist Martin Cordiner of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study. “On the one hand, we get direct insight into that distant time and place, and on the other, we learn something about how unusual our own solar system may be.” How old is old? It's now estimated that 3I/ATLAS formed some 10 to 12 billion years ago during a period of rapid star formation in the Milky Way. This puts this visitor at over twice the age of Sun and the rest of the Milky Way. “For us as scientists, finding these rare isotopes is fascinating, but the bigger picture here is looking at the possibilities of prebiotic chemistry elsewhere in the galaxy,” said Stefanie Milam of NASA Goddard and co-author of the study with Cordiner. “So far, we know of only one place in the vast cosmos where chemical ingredients led to life – our solar system, our Earth. Analysis of these interstellar objects is a major step towards learning how common, or uncommon, the conditions for the evolution of life are in the universe.” Where else has Comet 3I/ATLAS been? We don't have enough information about this comet to establish its full history certainty, but astronomers have indicated likely swung around over 60 of other stars over billions of years.  Are we looking for other interstellar visitors? Yes. Astronomers constantly keep an eye out for new comets as well as other types of interstellar visitors such as 'Oumuamua. Interestingly the Vera C. Rubin Observatory in Chile celebrated the first anniversary of its initial release of the wide field images. Even though this scans the entire southern night sky, it hasn't confirmed any new interstellar objects, although at least one candidate is under review. Read more about the age of Comet 3I/ATLAS at the NASA site here. The deepest ever images of the Milky Way's "Galactic Bulge" in visible light 60 Million Stars in this image which covers more than 20 times the area of the Full Moon   Astronomers with the European Space Agency (ESA) turned the Euclid Space Telescope to observe the centre of the Milky Way. Normally spending its time capturing wide field views of distant galaxies, the time spent photographing the heart of our home galaxy has produced a simply stunning image that shows some 60 million stars in a single frame. Euclid covered 4.8 square degrees of the sky with this image, corresponding to 22 times the area of the full Moon as seen from Earth. The image has been rotated counterclockwise compared to the celestial projection: north is to the left and east is down. It's of particular interest to Australian astronomers as this region is almost overhead during our winter months and many of our BINTEL customers have spent hours happily imaging the Milky Way using DSLR or mirrorless cameras and star tracker mounts. The location in the sky of this Euclid image “In 24 hours, Euclid has already captured the stars involved in all the future microlensing events that the Roman space telescope will detect, but before the stars and planets involved have aligned,” says Natalia Rektsini of the Institut d’Astrophysique de Paris in France, who led the release of Euclid’s galactic bulge survey data for the scientific community. “This means that anyone who detects a microlensing event in the same region, for example with Roman, will be able from now on to use Euclid data as a time reference in the past and see how the stars looked before they overlapped,” Natalia explains. “Since Euclid can clearly separate individual stars, one can then measure how fast they move over time and use that information to confirm the existence of a planet and determine its mass. This would not be possible with data from one point in time.” Read the full article here and see some more full resolution images. World's oldest impact crater is in Australia When you look at the Moon through even a small telescope, you can see a vast number of craters. These are round depressions that have been caused by impacts of space rocks hitting the Moon's surface.  You can even see craters within other craters, plus some appear slightly oval in shape.  There's caters like Imbrium Basin at about 1,455 km wide or even the South Pole–Aitken Basin which is some 2,500 km and one of the largest in the entire Solar System, while others visible are only a few km across.   Most of these craters resulted from impacts that happened during the Late Heavy Bombardment (LHB). This is a hypothesized period that saw a spike in asteroid and comet impacts that scarred the Moon and inner planets including Earth which was roughly 3.9 to 4.1 billion years ago. We sometimes have people ask us, "if the Moon is covered by craters, why don't we see them here on Earth?" The answer is yes, we have craters on Earth, and it was certainly hit by many objects just like the Moon. However, the Moon is basically a dead body, while the Earth constantly erases its craters through weathering, plate tectonics, and water coverage. Even so, some survive. The team from Curtin’s School of Earth and Planetary Sciences and the Geological Survey of Western Australia (GSWA) investigated rock formations at the North Pole Dome in the Pilbara region of Western Australia, By studying zircons, a mineral that "keeps time", they've now established them as being the results of an impact of approx. 3 billion years ago, making them the oldest crater formations found on Earth.  Lead author Professor Chris Kirkland, from the Timescales of Minerals Systems Group within Curtin’s School of Earth and Planetary Sciences, said the findings help resolve a longstanding question about the timing of the impact. “While the site had previously been identified as an ancient impact structure, its exact age remained uncertain,” Professor Kirkland said. “The impact left a ‘mineral clock’ behind. By dating minerals that were remade or newly grown in the damaged rocks, we can now pin down when this extraordinary event happened.   Read more at the Curtin University site here. Cheers, Earl White BINTEL 27th June 2026

Your eyes are probably not the same! Many people mightn't realise they have a slight difference in the focusing of their left and right eyes. It's something that's quite common and a diopter adjustment allows you to adjust for this variation between your eyes. It means that the binoculars have a different focus.  Binoculars usually have a small dial or ring that allows you to make a diopter adjustment.  How do I adjust the diopter? We tell people to close their right eye and look through your binoculars. (If this is tricky, put on just the right eyecup) then using just your left eye, focus your binoculars on something a little bit in the distance that has some crisp detail. This could be a tree branch, a rooftop or a traffic sign. Now, reverse the process. Shut your left eye or cover the left lens of your binoculars. This time don't touch the central focus wheel. Instead, adjust the diopter dial. This could be a dial around the outside of the right eyepiece such as the one on these Nikon Monarch M7 binoculars.  Depending on your binoculars, you just need to firmly twist them. On others, you might need to click up the right ring and then click it back down when you've finished the adjustment.  These Leica Trinovid binoculars at BINTEL use a click ring around the focuser to adjust the diopter. Twist the ring slowly from left to right to see if the image in your right eye comes more sharply into focus.  Hopefully it won't need much movement away from the central position at all! Next, switch eyes. Cover the left objective lens or close your left eye and now look only through the right side. This time do not touch the central focus wheel. Instead, turn the diopter ring until the same object is sharp for your right eye. Open both eyes or remove the left lens cap. You should notice that the view through your binoculars is a little sharper, especially if you need to twist the diopter dial more than a small amount.  The slight difference in your eyes has been "dialled" into your binos.  It might be worth repeating the process a couple of times focussing on different objects in the distance to fine tune the process. It's probably a good idea to make note of the diopter setting in case it gets bumped or you need to share your binos with other people.  What about if I wear glasses for long distance viewing and I want to use them with binoculars? If you use glasses for distance viewing, your optometrist has already taken into account the difference between your eyes as part of your glasses prescription.  You should be able to use your glasses with binoculars without the need to adjust the diopter setting.  The only thing to make sure of is that your binoculars have a decent eye relief. Eye relief is the distance behind the eyepiece at which your eye still sees the full field of view. Because your glasses hold the binoculars further from your eyes, you need longer eye relief to still see the whole image. Generally speaking, 15mm or more is comfortable for glasses wearers. What about if I wear glasses for long distance viewing and I don't want to use them with binoculars? In this case, there's a good chance you'll be able to use the focus to account for the change in focus your glasses perform. If the differences in your left and right eyes are too large for the diopter adjustment in your binoculars to cater for, you will need to still use your glasses. There are also some conditions, such astigmatism, that will still require you to wear your glasses.  This is only a brief introduction, so have a chat to us at BINTEL for more information! Cheers, Earl White BINTEL 26th June 2026