IRIX Firefly 15mm f/2.4 Firefly 15mm

The Irix Firefly 15mm f/2.4 is a niche manual-focus ultrawide that delivers good macro and optical quality for the price, especially if you snag a deal around $329. However, soft copies, heavy chromatic aberration, and zero AF mean it's not for everyone. Worth it for astro and landscape hobbyists on a budget, but pros should stay away.

The Irix Firefly 15mm f/2.4 is a manual focus ultra-wide prime built for Canon EF DSLRs. It's got a full-frame image circle, a fast aperture for its class, and weather sealing that's rare at this price. But there's a catch or two. The 15mm focal length gives you a dramatic field of view, and the built-in AE chip means auto metering works without any fuss on Canon bodies. At 599g, it's light enough to toss in a bag, and the focus lock is a nice touch for landscape work. However, it's manual focus only, and the 95mm filter thread means your usual ND kit probably won't fit. You're buying into a niche here, and that niche is budget-conscious shooters who don't mind turning a ring to get sharp results.

What you're really signing up for is value, but with asterisks. Our data shows the lens scores a mediocre 35.2 out of 100 overall, dragged down by weak versatility and bokeh scores. Yet it still has its moments. Macro performance stands out at the 71st percentile, and optical quality lands a solid 67th. The real story, though, is the price. Vendors list this lens anywhere from $329 to an absurd $65,788. Yes, you read that right. If you find it at the low end, it's a steal. At anywhere near the high end, run.

The lens shines brightest in macro and optical quality for its price. It sits in the 71st percentile for macro, surprising for a wide-angle, so close-up shots have decent detail. Optical performance is solid at 67th percentile, but that's tempered by the manual focus and middling build quality. Where it stumbles is versatility (35th percentile) and bokeh (22nd), which you'd expect from a 15mm f/2.4. The lack of stabilization and the aperture's modest f/2.4 put it behind many competitors, and its user sentiment is a worrying 17th percentile, dragged down by complaints of soft copies and chromatic aberration.

Prices for this lens are all over the map, from an absurd $65,788 at some sellers to as low as $329 at Amazon. At the low end, it's a steal for a full-frame ultrawide prime with weather sealing. But if you pay more than $400, the value proposition crumbles compared to newer APS-C autofocus alternatives. The sweet spot is definitely that $329 mark, where you get a lot of glass for not much cash.

Stacked against the Sigma 10-18mm f/2.8 DC DN or Viltrox 9mm f/2.8, the Irix loses on autofocus and size but offers full-frame coverage no crop sensor zoom can match. The Canons and Nikons listed are zoom lenses with slower apertures, so they're more versatile but can't touch the Irix's wide f/2.4 prime speed. If you're on a Canon EF DSLR and need an ultra-wide prime on a tight budget, this is a unique option that the big brands don't offer.

Skip this lens if you need autofocus or plan to shoot video. Also, if you're a pixel peeper who demands tack-sharp edges, the copy variation will frustrate you. Professionals should look for a more consistent and reliable ultrawide.

Buy the Irix Firefly 15mm if you're a Canon DSLR shooter who wants a dirt-cheap ultra-wide prime for astrophotography or landscapes and doesn't mind manual focus. It's also a solid macro option for wide-angle close-ups. But if video or autofocus matter to you, move on.