AstrHori MF 9mm f/2.8 Review

If you're shooting on a Canon RF APS-C camera and want to go really, really wide without breaking the bank, the AstrHori MF 9mm f/2.8 is a lens you've probably stumbled across. It's a manual focus prime that gives you a 13.5mm full-frame equivalent field of view, which is ultra-wide. For the price, around $169, you get a surprisingly solid metal build and optics that include one aspherical and two extra-low dispersion elements to fight distortion and color fringing. It's a niche lens, but for architecture, tight interiors, or creative landscapes on a crop sensor, it opens up possibilities that most kit lenses just can't touch.

Let's talk about what this lens does well. Its optical performance lands in the 69th percentile, which is decent for a budget manual lens. In practice, that means center sharpness at f/5.6 to f/8 is actually pretty good for the price. Distortion control is okay for such an extreme focal length, though you'll still see some barrel distortion that software can mostly fix. Where it shows its budget nature is in the corners, which get softer, and with chromatic aberration in high-contrast areas. The manual focus is smooth, and with a 77th percentile build quality, it feels more premium than it costs. The 0.2m (200mm) minimum focus distance lets you get close for some fun, slightly exaggerated perspectives, scoring a 73rd percentile in macro-like use. Just don't expect buttery bokeh (48th percentile) from an f/2.8 ultra-wide.

At $169, the value proposition is straightforward. You are paying for an ultra-wide focal length and a robust build, and you're accepting manual focus and some optical compromises. There are literally no autofocus ultra-wide primes for RF-S cameras at this price. If you need autofocus, you're looking at adapting an older EF-S lens or saving up for something like the Canon RF-S 10-18mm, which costs several times more. For a hobbyist, vlogger in a tight space, or real estate shooter on a tight budget who doesn't mind manual focus, this lens delivers a unique look for very little cash.

This lens sits in a weird spot because its main competitors aren't direct focal length matches. The Viltrox 13mm f/1.4 for RF-S is a closer comparison—it has autofocus, is sharper, and has a brighter aperture, but it's also over $400 and not as wide. The Sony E 15mm f/1.4 G is a fantastic APS-C lens for Sony, but it's in a different system and price league entirely. For Canon RF-S, the real competition is your own kit lens zoomed out, or the aforementioned Canon RF-S 10-18mm f/4.5-6.3 IS STM. The Canon zoom gives you autofocus, stabilization, and versatility, but it's slower (darker) and more expensive. The AstrHori 9mm is for when you absolutely need that extra width and light gathering of f/2.8 on a shoestring budget, and you're willing to focus manually.

So, should you buy the AstrHori MF 9mm f/2.8? It's a very specific yes. Buy this lens if you shoot with a Canon RF APS-C camera (like an R10, R50, or R7), you desperately want an ultra-wide perspective, your budget is firmly under $200, and you are completely comfortable with manual focus. It's a fantastic tool for creative, budget-conscious photographers. But if you rely on autofocus for quick shots, need corner-to-corner sharpness, or want a more versatile travel lens, this isn't it. Its low travel score (40.4/100) tells you it's a specialty tool. For everyone else, saving for a used Canon zoom or the Viltrox 13mm is probably the smarter play.