Quick intro
A 12–40mm and 40–150mm pair can cover an enormous amount of photography without turning your bag into a small gym membership. This guide shows where each lens is strongest, how to decide which one to mount, and how to work faster in the field. The central idea is simple: use the wider lens to tell the whole story and the telephoto lens to simplify it.
The idea: no mythology
There is no magic focal length, only useful tools for different visual jobs.
- Use the 12–40mm when the surroundings help explain the subject: landscapes, interiors, travel scenes, environmental portraits, groups, and close details.
- Use the 40–150mm when the subject matters more than the surroundings: portraits, wildlife, sports, distant details, candid moments, and cleaner compositions.
- The 12–40mm gives you more context. It invites the viewer into the scene.
- The 40–150mm gives you more separation. It helps remove clutter by narrowing your angle of view.
- Do not choose based only on distance. Choose based on what you want the frame to say.
- If you keep walking closer with the 12–40mm but the background still feels messy, the 40–150mm may be the better answer.
On an OM-1, these lenses are especially practical because the system stays compact while still giving you a wide equivalent range: roughly 24–80mm with the 12–40mm and 80–300mm with the 40–150mm. That is enough for most walks, trips, family events, and many paid assignments too.
What to shoot with the 12–40mm
Think of the 12–40mm as your “where are we?” lens.
At 12–18mm, it is excellent for landscapes, architecture, dramatic skies, and small rooms. The wide angle can make foreground objects look large and energetic, so get close to something interesting: a rock, a flower, a doorway, a bicycle, or a person in the scene. Empty foreground is just empty foreground with a wider lens attached.
Around 20–30mm, the lens becomes a very flexible everyday option. This range works well for travel photography, cafés, street scenes, food, family moments, and environmental portraits. It feels natural without becoming boring.
At 35–40mm, use it for tighter scenes and portraits where you still want a little location in the frame. This can be ideal for showing a person at work, a musician with their instrument, or a child playing in a room full of personality.
A useful question before mounting the 12–40mm: Would the image lose meaning if I removed the background? If the answer is yes, start wide.
What to shoot with the 40–150mm
The 40–150mm is your “look there” lens.
It is excellent when you cannot physically get closer, but its real superpower is composition. Longer focal lengths show less of the scene, making it easier to isolate a person, animal, gesture, colour, or pattern. In a visually chaotic place, that is almost cheating. Good cheating.
At 40–70mm, it works nicely for portraits with a natural perspective and a calmer background. At 80–150mm, it becomes strong for more distant portraits, wildlife, sports, stage performances, and graphic details in a landscape.
The telephoto lens can also make distant layers appear closer together. For example, a person walking along a path with hills or buildings behind them may look more compressed and visually connected. With the 12–40mm, those same background elements might appear tiny and far away.
Before mounting the 40–150mm, ask: Is the background hurting the image more than it is helping? If it is, reach for the telephoto.
A simple field workflow
Start by photographing the obvious scene with the 12–40mm. Make one wide frame that shows the location, then move closer for medium and detail shots. This gives you a complete visual record before you become too selective.
Look for a single subject or clean shape. It could be a person, bird, face, hand, window, tree, or patch of light. If the scene feels busy, switch to the 40–150mm and simplify the frame.
Change lenses when the story changes, not every two minutes. Give each lens a small assignment: “ten minutes for the scene” with the 12–40mm, then “ten minutes for isolated details” with the 40–150mm. Constant swapping usually produces dust, hesitation, and an impressive collection of missed moments.
Practical settings example
The OM-1 has excellent stabilisation and capable autofocus, but your settings should follow the subject rather than the camera’s marketing brochure.
Scenario 1: A travel street scene with the 12–40mm
You are photographing a person walking through an interesting street, with buildings and light contributing to the scene.
- Lens: 12–40mm at 17mm
- Mode: Aperture Priority
- Aperture: f/4
- ISO: Auto ISO, maximum ISO 3200
- Minimum shutter speed: 1/250 sec
- AF mode: Single point or small AF target placed on the person
- Exposure compensation: -0.3 EV if bright sky occupies a large part of the frame
At 17mm and f/4, you have enough depth of field to keep both the person and much of the environment readable. The 1/250 sec minimum helps prevent motion blur when people walk through the frame.
Scenario 2: A portrait with the 40–150mm
You are photographing a person outdoors, with distracting bushes, parked cars, or random visual nonsense behind them.
- Lens: 40–150mm at 100mm
- Mode: Aperture Priority
- Aperture: f/4
- ISO: Auto ISO, maximum ISO 1600
- Minimum shutter speed: 1/500 sec
- AF mode: Face and Eye AF
- Drive mode: Low continuous burst
At 100mm, step back and let the background fall out of focus. The longer focal length also prevents you from standing uncomfortably close to your subject. Everyone appreciates that.
Scenario 3: A bird or moving subject with the 40–150mm
- Lens: 40–150mm at 150mm
- Mode: Manual exposure with Auto ISO
- Shutter speed: 1/1600 sec
- Aperture: f/4
- ISO: Auto ISO, maximum ISO 6400
- AF mode: Bird Detection or Continuous AF with an appropriate subject-detection mode
- Drive mode: Sequential shooting
For moving subjects, shutter speed is your first priority. A little noise is usually easier to accept than a perfectly clean photo of a very blurry bird.
For a refresher on balancing aperture, shutter speed, and ISO, see The Exposure Triangle in 10 Seconds.
EXIF example
Example settings scenario — not real EXIF capture data:
A person stands near a window inside a museum-like interior. You want a portrait that includes some of the space without blur from small movements.
- Camera: OM-1
- Lens: 12–40mm at 30mm
- Aperture: f/2.8
- Shutter speed: 1/160 sec
- ISO: 1250
- Metering: Evaluative/ESP
- AF: Face and Eye AF
- File type: RAW
This is a sensible starting point, not a sacred recipe. Check the histogram, protect bright window highlights where possible, and adjust exposure compensation if the camera makes the person too dark.
Common mistake: choosing the lens only by distance
A common mistake is thinking, “The subject is close, so I need the 12–40mm,” or “The subject is far away, so I need the 40–150mm.” Distance matters, but visual intention matters more.
You can spot this mistake in your photos when the subject looks small and lost in a large frame, or when the background is full of distractions that do not add anything. Another warning sign: you keep cropping heavily at home because you did not use the telephoto to simplify the composition in the first place.
If your image feels weak, ask one question: Am I showing too much, or not enough? Too much usually suggests the 40–150mm. Not enough context often suggests the 12–40mm.
If exposure is confusing in mixed light, this guide to metering modes can help. For checking whether you have protected important highlights, use the histogram instead of guessing.
Mini practice task: the two-story walk
Set aside 10 minutes.
For the first five minutes, use only the 12–40mm. Make three photographs of one area: a wide establishing frame, a medium frame, and a close detail. Try to make the surroundings useful in every image.
For the next five minutes, mount the 40–150mm and photograph the same area without repeating the same compositions. Look for isolated faces, colours, reflections, hands, signs, textures, or distant layers. Review both sets afterward and notice how the first lens describes a place while the second lens edits it.
Wrap-up
The 12–40mm is for context, proximity, and visual variety; the 40–150mm is for isolation, reach, and cleaner compositions. Carry both, but give each lens a clear job—and your photos will feel more intentional before you even open the editing software.