How to Switch Between Autofocus (AF) & Manual Focus (MF) on the Olympus M.Zuiko 12-40mm ƒ/2.8 Zoom Lens

Here’s how to switch between Autofocus (AF) and Manual Focus (MF) modes on the Olympus M.Zuiko 12-40mm ƒ/2.8 zoom lens.

Olympus M.Zuiko 12-40mm ƒ/2.8mm Zoom Lens Front Element
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This is something that originally had me stumped. So I thought it worth posting a quick note here in case anyone else ran into the same issue.

Olympus is now OM System

In 2020-21, the photography business of iconic camera brand Olympus was spun off and sold. The core remaining Olympus brand is focusing on medical and scientific products. The camera and photography side was then rebranded as OM System, with the first cameras and lenses under that brand coming out at the end of 2021.

I was recently out shooting with the Olympus M.Zuiko 12-40mm ƒ/2.8 lens, and when I took it out my camera bag it was in manual focus mode. And I couldn’t find a way to switch the Olympus 12-40mm lens from manual focus to autofocus. I was looking for buttons or switches on the lens. I looked for menu settings on the camera. I even had to do a web search to confirm that there wasn’t a version of the lens that was manual focus only. It had me stumped.

The 12-40mm lens doesn’t have a button or switch. Instead, you use the focus ring itself.

While I’m referring here to the 12-40mm lens, I’ve since learned that several other Olympus/OM System lenses have the same type of mechanism for switching between manual and automatic focus.

To put it in autofocus mode, slide the focus ring away from the camera body until it clicks in place. Like this:

Olympus M.Zuiko 12-40mm f2.8 Zoom Lens Focus Ring
This is switched to autofocus, with the focus ring clicked forward (away from the camera).

To switch to manual focus, slide that same ring towards the camera body. That will also expose the focus distance ruler printed on the lens barrel’s surface. Like this:

Olympus M.Zuiko 12-40mm f2.8 Zoom Lens Focus Ring
This is switched to manual focus, with the focus ring clicks backwards towards the camera and exposing the focus measure marks.

So it turns out that the solution is very simple. And, when you know about it, it’s actually quite intuitive. But if you don’t know about it, it’s not immediately apparent–at least, not to me–because it’s not the way that most other lenses do it. Not that it matters, because it’s not like there’s another option on this lens, but it’s not my favorite implementation of the toggle because I’ve found it too easy to accidentally toggle it as I’m pulling the lens in or out of my bag and there’s no locking mechanism.

Anyway, I hope this saves someone else some temporary confusion!

Related: Olympus / OM System Lens Filter Size Chart

David Coleman / Photographer
by David Coleman

I'm a professional freelance travel photographer based in Washington DC. Seven continents, up mountains, underwater, and a bunch of places in between. My images have appeared in numerous publications, and you can check out some of my travel photography here. More »