OM System M.Zuiko 100-400mm f/5-6.3 IS vs OM System M.Zuiko 12-40mm f/2.8 PRO II

Both are Micro Four Thirds mount zooms for travel — here's how the specs differ and which to pick. Every spec is from the manufacturer's own catalog.

Last verified 2026-06-21 · Micro Four Thirds mount · prices change — check the retailer

Spec	OM System M.Zuiko 100-400mm f/5-6.3 IS	OM System M.Zuiko 12-40mm f/2.8 PRO II
Focal length	100-400mm	12-40mm
Max aperture	f/5-6.3	f/2.8
Type	zoom	zoom
Coverage	Micro Four Thirds	Micro Four Thirds
Mount	Micro Four Thirds	Micro Four Thirds

Which should you buy?

• the OM System M.Zuiko 12-40mm f/2.8 PRO II opens wider (f/2.8) — brighter in low light and more background blur
• the OM System M.Zuiko 100-400mm f/5-6.3 IS covers 100-400mm and the OM System M.Zuiko 12-40mm f/2.8 PRO II covers 12-40mm — pick the range that matches what you shoot

Where to buy

Check the OM System M.Zuiko 100-400mm f/5-6.3 IS price on Amazon →

Check the OM System M.Zuiko 12-40mm f/2.8 PRO II price on Amazon →

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FAQ

What's the difference between the OM System M.Zuiko 100-400mm f/5-6.3 IS and the OM System M.Zuiko 12-40mm f/2.8 PRO II?
The OM System M.Zuiko 100-400mm f/5-6.3 IS is 100-400mm f/5-6.3 zoom, Micro Four Thirds; the OM System M.Zuiko 12-40mm f/2.8 PRO II is 12-40mm f/2.8 zoom, Micro Four Thirds. Both fit the Micro Four Thirds mount.

Which is better in low light, the OM System M.Zuiko 100-400mm f/5-6.3 IS or the OM System M.Zuiko 12-40mm f/2.8 PRO II?
The OM System M.Zuiko 12-40mm f/2.8 PRO II — its f/2.8 maximum aperture lets in more light and gives more background blur than the f/5-6.3 of the other.

Do the OM System M.Zuiko 100-400mm f/5-6.3 IS and OM System M.Zuiko 12-40mm f/2.8 PRO II fit the same camera?
Yes — both are Micro Four Thirds mount lenses, so they fit OM System (Olympus) and Panasonic Lumix G Micro Four Thirds bodies.

More Micro Four Thirds comparisons: OM System M.Zuiko 100-400mm f/5-6.3 IS vs Panasonic Lumix G 100-300mm f/4-5.6 II · OM System M.Zuiko 17mm f/1.8 vs Panasonic Leica DG 15mm f/1.7 · OM System M.Zuiko 40-150mm f/2.8 PRO vs OM System M.Zuiko 150-600mm f/5-6.3 IS · OM System M.Zuiko 40-150mm f/2.8 PRO vs Panasonic Leica DG 50-200mm f/2.8-4 · all Micro Four Thirds lenses · all comparisons