The Micro Four Thirds Prime That Punches Above Its Size

A small, bright, ultra-wide lens can make your kit far more flexible. If you’re shooting landscapes, waterfalls, or night skies, carrying one compact prime instead of a heavy zoom changes how long you can stay out and what you can bring back.

Coming to you from Waterfall Joe, this detailed video covers the Panasonic Leica DG Summilux 9mm f/1.7 ASPH lens and why it stands out in the Micro Four Thirds lineup. At just 2 inches long and 130 g, it’s small enough to live on your camera all day without dragging you down. The weather-sealing makes it a solid choice for shooting around water, in the rain, or in unpredictable conditions. The f/1.7 aperture opens up low-light options, letting you move between landscapes and astrophotography without swapping lenses. You also get the benefit of standard 55mm filters, so you can throw on a polarizer or ND without tracking down odd sizes.

The video walks through the competition in this focal range and points out where trade-offs appear. The OM System 8mm f/1.8 fisheye is fast and wide, but it's a fisheye. Laowa has manual focus 6mm and 10mm primes if you want even wider, but that comes at the cost of autofocus. Zooms like the OM System 7–14mm f/2.8 or Panasonic 8–18mm f/2.8–4 bring range, not compactness. If your goal is to keep things light while still being able to shoot sharp, rectilinear wide frames without distortion, the 9mm strikes a balance that few others in the system match.

Key Specs

• Focal Length: 9mm (18mm equivalent)

• Aperture: Maximum f/1.7, Minimum f/16

• Lens Mount: Micro Four Thirds

• Minimum Focus Distance: 3.7 in / 9.5 cm

• Magnification: 1:4 reproduction ratio, 0.25x magnification

• Optical Design: 12 elements in 9 groups

• Aperture Blades: 7, rounded

• Focus Type: Autofocus

• Image Stabilization: None

• Filter Size: 55 mm (front)

• Dimensions: ø 60.8 x L 52 mm

• Weight: 4.6 oz / 130 g

Beyond the spec sheet, you see how it actually works in the field. Mounted on an OM-1 Mark II, it’s a natural fit with Live ND modes for handheld long exposures of waterfalls. The lens stays sharp stopped down around f/5.6–f/8, while still delivering usable results wide open at f/1.7. The short  focus distance lets you push in tight on branches or foreground textures with a waterfall still filling the background. For astrophotography, the combination of wide angle, fast aperture, and compatibility with OM System’s starry sky autofocus makes it a simple grab-and-go setup.

The video highlights that while there are larger, more flexible zooms, few primes in any system give you this mix of size, aperture, and weather-sealing at around $500. If you already rely on a telephoto and mid-range zoom, adding this compact 9mm fills the wide end without weighing you down. Check out the video above for the full rundown from Joe.