Zoom eyepieces tend to have a bad reputation, but the Baader Hyperion Universal Zoom Mark IV eyepiece with Hyperion-Barlow 2.25x is a potent combination that can replace an entire set of budget or mid-range eyepieces while still offering something special for advanced stargazers.
To zoom or not to zoom?
Any telescope for serious use needs to be coupled with a variety of high-quality eyepieces to cover various focal lengths for a range of magnifications and field widths. There’s something undeniably satisfying about a case full of eyepieces, and many astronomers get a lot of enjoyment collecting them over the years. Zoom eyepieces are an alternative approach, offering multiple focal lengths in a single eyepiece. While undeniably convenient, they often offer poor performance compared to their non-zoom equivalents. Baader is well known in the eyepiece market and has designed several zooms over the years. The Baader Hyperion Universal Zoom Mark IV is their latest attempt at producing a high-quality zoom, and there’s certainly a lot to like about it.
Its focal lengths range from 8-24mm, which is respectable. For higher magnifications, Baader offers the Hyperion-Barlow 2.25x, which makes the eyepiece 3.6mm-10.7mm. The Baader Hyperion Universal Zoom Mark IV eyepiece and Hyperion-Barlow 2.25x can be purchased separately or together at a discount.
I tested a Baader Hyperion Zoom Mark IV with my Askar 130PHQ Flatfield Astrograph (reviewed for AGT here) and an older-style William Optics GTF81. The Moon through the large Askar was absolutely stunning, and here the eyepiece really shone. Twisting my way through the focal lengths gave different views of the lunar surface, from sweeping landscapes at the wide end to crisp craters when zoomed in. The experience was seamless, and more immersive than switching between different eyepieces. Adding the Hyperion-Barlow 2.25x made it feel like the Moon was within reach. Image quality is often where zoom eyepieces fall down but the Baader Hyperion Universal Zoom Mark IV bucks this trend. It’s very sharp, even with the Barlow, and images are bright with good contrast thanks to Baader’s “Phantom Coatings”.
On to Jupiter, and the eyepiece didn’t disappoint, with orange bands well-defined and clear. I did notice a little chromatic aberration but didn’t find it too distracting. By this time Mars was in a good position so I turned the telescope toward the red planet. Not much could be seen with the eyepiece alone but adding in the Hyperion-Barlow 2.25x really stepped things up a gear and allowed me to make out dark surface features.
I was pleased to find that the eyepiece twists smoothly to select different focal lengths. Key stages – 8mm, 12mm, 16mm, 20mm, and 24mm – have tactile click stops when you reach them. These will be particularly useful if using a pair of these eyepieces with a binoviewer, allowing you to set your eyepieces by feel alone, although I’d have liked the bumps to be a bit more pronounced.
Nearby was the Pleiades, and while the stars had a pleasing sparkle, I encountered an issue with the eyepiece. The field of view is a pleasantly wide 68° at 8mm, but gradually reduces as you zoom out, ending at 48° once you reach 24mm – the focal length where you actually want the widest view to encompass large targets such as open clusters. I found the view to be a little tight at 24mm, which is an annoyance that will range from minor to deal-breaking depending on how much you want a wide field of view at low magnifications. Switching to the William Optics GTF81 at this point gave me the wider view that I wanted, and I then continued zipping from target to target. The eyepiece and matching Barlow were great fun to use!
A dizzying array of adapters and accessories are included, making the eyepiece compatible with almost any set-up. Various labelled diagrams and photos adorn the box but I recommend reading the comprehensive manual that Baader provides online. Special shoutout for the supplied case, which, unusually for astronomy products, is well-designed and genuinely useful. The bright canary-yellow color helps it to stand out in the dark, and elastic ensures a snug fit. It even has a secure Velcro and strap for attaching to your belt. The only downside to the case is that it can’t also accommodate the Hyperion-Barlow 2.25x, which is a real shame.
Speaking of the Barlow, it’s designed specifically for the Baader Hyperion Zoom range of eyepieces. It screws into the bottom of the eyepiece, making it very secure, but it is a little fiddly to do in the dark and with numb hands. When using the Barlow, you also have more protective caps to keep track of, and these are particularly small and easy to lose. The process of attaching and detaching does compromise the seamless zoom aspect somewhat, but still, the Hyperion-Barlow 2.25x is an excellent addition.
If you’re an experienced observer used to premium non-zoom eyepieces then you’ll likely find that this eyepiece doesn’t meet your standards, but for everyone else it will leave you very pleasantly surprised. Although not cheap, when considering it can replace a whole collection of beginner or mid-range eyepieces, especially when coupled with the Hyperion-Barlow 2.25x, it represents good value.
If you are an eyepiece connoisseur then there may still be a place for the Baader Hyperion Universal Zoom Mark IV and Hyperion-Barlow 2.25x in your collection for use at public events and star parties, leaving your more precious eyepieces safely at home. Given the ease of use, high fun-factor, and sense of immersion that seamless zooming gives, you may find that you start leaving your other eyepieces in their case!
* Very good image quality throughout entire zoom range
* More convenient than multiple separate eyepieces
* Supplied with lots of accessories
* Field of view a little narrow at 24mm
* Hyperion-Barlow 2.25x fiddly to attach if you have numb hands; and lots of caps to keep track of
Baader Hyperion Universal Zoom Mark IV eyepiece: $309
Eyepiece with Hyperion-Barlow 2.25x: $419