Most beginner telescopes include an eyepiece or two to get users started, often a wide 25mm or 30mm version plus a higher-magnification option.
While these can offer new astronomers some memorable first views, often it’s not long before you’ll want to expand and upgrade your eyepiece collection.
Read our beginner’s guide to telescope eyepieces and browse our eyepiece reviews
The variety available can be daunting, as can the cost, so we’re seeing how the budget-friendly Ursa Major fully multicoated (FMC) flatfield eyepieces measure up.
Ursa Major offers its FMC flatfield eyepieces in 3.5mm, 5.5mm, 7.5mm, 10.5mm, 15.5mm, 19mm and 25mm options, which covers most visual scenarios.
These are advertised as an alternative to the more common Plössl or orthoscopic eyepieces, and offer several benefits over these rivals, including very generous eye relief.
Unboxing
The full set of Ursa Major multicoated flatfield eyepieces is designed for 1.25-inch focusers or diagonals, so on first impressions were very compact and lightweight, with the 3.5mm and 25mm being the tallest of the range.
Each eyepiece arrived in a sturdy box, wrapped in a plastic bag. Also included was a soft cleaning cloth and a pair of rubber dust caps.
The 15.5mm, 19mm and 25mm versions offer a superb 65° field of view, dropping only slightly to 60° for the 10.5mm, 7.5mm, 5.5mm and 3.5mm.
Compared to a Plössl eyepiece, which commonly provides in the region of a 50° field of view, the Ursa Major multicoated eyepieces appear to give the wide-angle vistas we’d expect from more expensive ranges.
How the Ursa Major multicoated eyepieces perform
Setting up our 81mm refractor, we first slewed over to an almost full Moon.
Starting with the 25mm eyepiece, we were immediately impressed with the crisp, high-contrast views.
Despite being very bright, there was only a tiny amount of colour fringing evident, which nevertheless really didn’t distract from the view.
Stepping down through the 19mm and 15.5mm, our views continued to be excellent.
Arriving at the 10.5mm, we started to notice a distinct drop in contrast, which continued as we stepped further down the focal lengths.
Arriving at 3.5mm, we found the views quite soft and dark. However, at 136x magnification it was approaching our telescope’s optical limits under some questionable sky conditions.
Switching back to the 25mm, we next slewed over to Vega, which we were pleased to see as a bright, pinpoint star in the middle of the eyepiece, with crisp and tight stars speckled across most of our field of view.
We did note that the very outer edges showed distortions, including some stars flaring, but the centre two-thirds of the view showed excellent star shape.
Moving back down through the range again, the edge views improved and the distortions were less noticeable.
While in the vicinity of Vega, we hopped over to the multiple-star system Epsilon Lyrae, the Double Double.
Between 25mm and 15.5mm, we could clearly identify the stars as a distinct pair, while the 10.5mm and 7.5mm versions started to hint that there was more to our target.
It wasn’t until we got down to the 5.5mm and 3.5mm eyepieces that we could easily split both pairs and see dark space between them.
Sticking with double stars, we slewed over to Albireo.
As a wider system, we could easily split it across the entire range, but the contrasting colour of the two stars is what makes this target special.
Each eyepiece didn’t disappoint and all focal lengths gave great views and beautiful colour contrasts.
Summary
The Ursa Major multicoated eyepieces may have a budget price, but they punch well above their weight, offering excellent value for money.
If you’re eyepiece shopping, we’d recommend using a field of view calculator to ensure that you are getting the best match for your particular setup, as more power doesn’t always mean better views.
Any options from Ursa Major’s FMC range should make a respectable upgrade from the standard offerings supplied in many telescope kits.
With a large range of focal lengths available, combined with a comfortable user experience, there will be something for everyone.
Ursa Major multicoated eyepieces’ optics
The Ursa Major flatfield multicoated eyepieces’ optical system design varies across the range, comprising five or six lenses in three or four groups, depending on the focal length.
The glass elements are fully multi-coated to reduce reflections and improve colour correction, while the entire range offers excellent eye relief – 23mm on the 25mm, down to a still impressive 15mm on the 3.5mm.
The lower the eye relief, the more difficult it is for spectacle wearers to have a rewarding viewing experience.
Given that many high-end eyepieces offer less than 10mm of eye relief, this Ursa Major set ensures an easy-to-use experience that encourages beginners.
Each eyepiece in the range has distinctive large front-glass elements. Even the punchy 3.5mm has an element that almost fills the end of the eyepiece.
Combined, these optical features make the Ursa Major FMC flatfield range particularly accessible. We can imagine these coming into their own at public outreach events.
Ursa Major multicoated eyepieces best features
Rubber eyecups
Each of the Ursa Major multicoated eyepieces is fitted with a soft fold-down rubber eyecup. These help to keep your eye in the optimal position without causing knocks or vibrations, while also preventing light from disrupting your views. These can also be folded back to allow spectacle wearers extra eye relief.
1.25-inch barrels
Fitted with black-painted 1.25-inch barrels, the Ursa Major FMC eyepieces are compatible with all focusers that can accept 1.25-inch eyepieces. Each eyepiece barrel is also tapered to increase grip within the focus tube, reducing the risk of falling out while slewing to targets or if accidentally knocked.
Filter screw threads
The inner side of the barrel of each eyepiece is threaded to accept 1.25-inch filters, such as light-pollution filters, coloured filters or neutral-density filters. This can dramatically improve your viewing sessions when under light-polluted skies or viewing a bright Moon, by boosting target contrasts and enhancing definition.
Ergonomic lightweight design
The full-metal construction is finished in black, with two bands of textured rubber around the centre for increased grip, providing a secure feeling while handling. Weighing between 80g and 110g, the range is extremely compact and light, limiting the risk of our telescope’s focus barrel slipping mid-use.
Dust caps
Just like the eyecups, the dust caps are made of a soft rubber material that fits each eyepiece securely, but can be installed and removed easily, even if wearing gloves. The snug fit ensures they stay in place and prevents dust accumulating if stored in a pocket between uses.
Vital stats
- Price: £39 each
- Focal length: 3.5mm, 5.5mm, 7.5mm, 10.5mm, 15.5mm, 19mm, 25mm
- Lens design: Flatfield
- Apparent field of view: 60° and 65°
- Eye relief: 15mm (3.5mm), 16mm (5.5mm–15.5mm), 20mm (19mm), 23mm (25mm)
- Optical elements: 5 or 6
- Barrel size: 1.25-inch
- Extras: Cleaning cloth, dust caps
- Weight: 80g–110g
- Supplier: First Light Optics
- Email: questions@firstlightoptics.com
- www.firstlightoptics.com
This review appeared in the September 2024 issue of BBC Sky at Night Magazine