I had other Starguider eyepieces before buying the 5mm, and like the rest of the range, it gives a good performance at the price. I can't see any obvious faults with the definition, which is maintained well even at the edges. There's a bit of pincushion distortion, but very few eyepieces are entirely without this, in my experience, and it isn't as serious a fault in an eyepiece as it would be in a photographic objective. I've bought the entire range, because of the reasonable price, with the exception of the 15mm, which is too close to the 12mm and 18mm if you already have these. Because of the cost, I've been able to buy two examples of some of them, to use with a pair of 100mm binoculars. They fit this purpose very well, as the rigid screw-up eyecups can be rested precisely against the orbital bone around the eye, which makes it easier to keep the exit pupils of the binoculars aligned with both eyes at once. This is also useful on a telescope, where these eyecups help to keep the eyepiece accurately positioned in bright light at high magnification, when you have to aim a narrow exit pupil into your narrow eye pupil.

Used with skywatcher 127mm to take it to 300x. Live in bortel 4 area . Very good build quality and will last for years. Great views of venus edge to edge. Slight blaring at this range but still good. Nice 60 degrees FOV. No aberration noted. Getting about 35 seconds before adjusting the tracking. Very good quality and very please. Would definitely recommend.

I've read many positive comments about this eyepieces before buying one. I must admit that the hype is real. These are very good value for money. Sharp all the way to the edges, excellent AC control, comfortable EF, good build quality. All this goodies for an excellent price. I'll be buying another one for sure

I decided to upgrade from the basic plossl eyepieces I got with my scope (a Skywatcher 8inch dobsonian). There’s a lot of choice out there, some of which are really expensive. I didn’t want to go really low budget but also didn’t want to break the bank. I decided upon BST 5mm and 12mm starguider eyepieces. As I’m mostly viewing the moon and planets, these seemed the right fit for me. In a word “amazing”! It’s like I’ve bought a much better telescope. I’ve had 4 nights of using them on the moon so far, the detail is crystal clear and the FoV and eye relief are excellent (I wear glasses). Going to try the 25mm next. Highly recommended.

Best suited to moderate focal length telescopes to deliver a high power view. Generous field of view and eye relief make it a pleasure to use. Excellent value.

I'm using it with 72ED. works quite nice. The image quality is good. Jupiter feels very close when I'm using it.

Well put together eyepiece that gives a decently corrected image on axis and out to about 80% of the field. Comfortable twist up eyecup. This range of eyepieces are a very good stepping stone from the ones supplied with most telescopes

Really impressed with the quality feel of these eyepieces. They are a 110% improvement on my previous eyepieces giving a bright, clear and sharp view.

I spent several hours enjoying the views with this scope with it's supplied eyepieces then, during weeks of cloudy skies, I ventured down the rabbit hole of selecting some new eyepieces.
The Stargazers Lounge forum was incredibly helpful (thanks to FLO for sponsoring it) and led me to getting 5mm, 8mm and 15mm BST Starguider eyepieces, (giving 240x, 150x and 80x with this scope. I later added a 32mm plossl for low magnification.)

The difference is staggering! For a start the wider field of view (60deg) means less of the "looking down a long thin tube" effect at higher magnifications. To my eyes the images are bright, sharp and show very little distortion. This 5mm is about on the limit for magnification for our skies (Bortle 4, in theory) but, on those good-seing nights, it shows the finer detail of Jupiter, Saturn and the moon really well. It is ideal for splitting double stars too.
Even at this magnification (240x) It is still relatively easy to hand guide the dob.

For me and for this scope they have been an excellent (and inexpensive) upgrade. I thoroughly recommend them.

FLO's service, speed of response, quality of packaging and choice of courier are all excellent. (I live in France - express delivery took just 3 days!)

Thankfully my package didn't arrive with clouds and I was able to try them on the first night. I'm quite impressed. The fine detail I can see in the moon with my Heritage 130p is mind blowing compared to the eyepieces that came with the scope. And for the price (especially with the discounts of buying more than 1), I feel it's a great deal that anyone interested in expanding their eyepiece collection should take on.
Also, props to the FLO team for their professionalism and swiftness. I'll be returning here as a happy customer in the future.