Why the 40-150mm f/4 PRO Could Be Your Next Travel Lens

A telephoto lens that fits into a jacket pocket changes how you think about traveling with your gear. When you want reach without the burden of a heavy lens, size and weight matter as much as sharpness and build quality.

Coming to you from Waterfall Joe, this detailed video breaks down the OM SYSTEM M.Zuiko Digital ED 40-150mm f/4 PRO lens. The lens came out in early 2022 and quickly earned attention for being unusually compact for a telephoto. At 382 g, it’s about the size of a mid-range zoom, yet it gives you an 80 to 300mm equivalent on Micro Four Thirds cameras. You get a constant f/4 aperture, weather-sealing, and a solid all-metal build. What stands out is how much of this functionality is packed into something only 3.9 inches long, which means you can carry it anywhere without feeling weighed down. For travel, that’s a big deal.

The lens sits in an interesting spot within the OM SYSTEM lineup. You have two other 40-150mm options: the f/2.8 PRO for those who need more low-light performance and teleconverter support and a cheaper variable-aperture version aimed at casual shooters. Compared to the f/2.8, the f/4 PRO is half the size and nearly half the weight. If you’re working in bright conditions, this trade-off makes a lot of sense. It also pairs neatly with other f/4 zooms in the system, like the 8-25mm, 12-45mm, and 12-100mm, all of which share weather-sealing and consistent build quality. That uniformity makes switching between lenses straightforward when you want a lightweight but reliable kit.

Key Specs

• Focal Length: 40 to 150mm (35mm equivalent: 80 to 300mm)

• Aperture: f/4 maximum, f/22 minimum

• Lens Mount: Micro Four Thirds

• Minimum Focus Distance: 27.6" / 70 cm

• Magnification: 0.41x, 1:2.44 macro reproduction ratio

• Optical Design: 15 elements in 9 groups

• Aperture Blades: 7

• Focus Type: Autofocus

• Image Stabilization: None

• Filter Size: 62 mm

• Dimensions: ø 2.7 x L 3.9" (69 x 99 mm)

• Weight: 13.5 oz / 382 g

One clever design feature is its storage mode. When collapsed, the lens locks into a compact state, making it easier to fit in your bag. Unlike many zooms, it doesn’t extend as you move through the focal range. That stability helps with balance and keeps it discreet. On top of that, it shares the same 62mm filter size as the 12-40mm f/2.8 PRO, which saves you from buying duplicates if you already own filters for that lens.

Joe also points out the creative opportunities the lens opens up. Beyond wildlife and travel, he found himself experimenting with minimalism by focusing on textures, patterns, and details in landscapes he might have overlooked with a wide angle. The long reach changes how you see scenes, nudging you to search for smaller stories inside bigger environments. Check out the video above for the full rundown from Joe.