Camera Bulb Mode: How To Use It

In this article, we’re going to walk through what bulb mode is, how to use it, and some practical ideas you can try out with this often underused setting.

What is Bulb Mode

Bulb mode isn’t something you hear talked about all that often. Most photographers are familiar with automatic and manual mode, but then there are all these other options on your mode dial that often get ignored. Bulb mode is usually represented by the letter ‘B’.

When you switch to bulb mode, your shutter speed becomes fully manual. The concept is simple. The shutter stays open for as long as you hold down the shutter button. You see? Simple! 

In manual mode, your shutter speed is typically capped at around 30 seconds. Bulb mode removes that limit allowing you to expose for a few seconds, a couple of minutes, or longer if needed. That said, if you’re not planning to go beyond 30 seconds, there’s no real need to use bulb mode.

When to use Bulb Mode

Bulb mode is designed for long exposures, but not necessarily the kind you might first think of.

You’ve probably seen those incredible astrophotography shots with star trails circling the sky or detailed images of the Milky Way. Most of those are actually created by stacking multiple shorter exposures rather than using one continuous exposure in bulb mode. That’s important to understand, because extremely long exposures can cause issues like sensor overheating and battery drain.

Where bulb mode really shines is in exposures lasting several minutes. Things like traffic trails, night cityscapes, light painting, and certain landscape shots are perfect for this setting. These are the kinds of scenarios where having full control over your exposure time makes a real difference.

How to use Bulb Mode and Get Good Results

There are a couple of ways to access bulb mode. Some cameras have a dedicated ‘B’ setting on the mode dial. On others, you can switch to manual mode and scroll your shutter speed past 30 seconds until ‘B’ appears.

To take the shot, press and hold the shutter button to begin the exposure, and release it when you want it to end.

However, there are a few essentials to keep in mind before taking these shots. A tripod is completely non-negotiable. Even for one-second exposures you need stability, so for multi-minute shots it’s absolutely critical.

A remote shutter release is also highly recommended. Pressing the shutter button introduces slight movement, and releasing it does the same. Over a long exposure, even that small movement can soften your image. A remote allows you to keep your hands off the camera entirely.

Settings

You’ll want to keep your ISO as low as possible. This helps prevent overexposure and reduces noise in your image.

Aperture will depend on your scene and how long you plan to expose. A good starting point is around f/8 to f/11. From there, adjust based on how your highlights are looking and how much light is entering the frame.

As with most night photography, it’s best to slightly underexpose your image and shoot in RAW. RAW files give you more flexibility in post, especially when recovering shadows. Highlights, once blown, are far harder to bring back, so it’s always safer to protect them.

White balance is another setting to lock in. If left on auto, it can shift during a long exposure and give you inconsistent or muddy colours. Set it manually based on your scene before you shoot.

Bulb Mode Shooting Ideas

Long Neon Light Trails

So my usual style of photography is neon night photography, and city-wide shots with long traffic trails always come out really well. But you may wonder if a standard 30-second exposure might just do the trick.

Well imagine this: if you’re taking photos at an intersection, you ideally want traffic covering the whole road. With just 30 seconds, you’re likely only going to capture one direction of traffic. Bulb mode allows you to extend that exposure as the traffic lights change, covering every inch of the road in light trails and giving you a much fuller scene.

Reflections

The reflections of lights on rainy streets are what first drew me into photography, and using them in conjunction with bulb mode can yield some fantastic results. The reflections start to build up over time, and you may even get the odd scooter or taxi passing through your frame to add texture and variation.

If you’re on a really busy street, bulb mode works even more in your favour, allowing all of that movement and light to accumulate into something much more dynamic, which leads nicely into the next idea.

Removing people from busy streets

Long exposure captures everything that is stationary or producing light. If you imagine a typical street in Seoul, it’s a continuous stream of people moving through your scene.

With a long exposure, especially using bulb mode, it will look as though they were never there. Because they are constantly moving and not emitting much light, they simply don’t register in the final image. You might see the occasional glow from a phone or reflection, but that often adds to the overall texture rather than distracting from it.

Landscape Shots

Long exposure also works beautifully in the outdoors. It’s most commonly used with running water to create those smooth, glass-like surfaces as the motion is averaged out over time. This works particularly well for rivers, coastlines, and waterfalls.

It can also be used for night landscapes, where you may need to expose for several minutes due to low light. Don’t expect highly detailed stars in the sky, as astrophotography is usually achieved by stacking multiple exposures. However, you may notice subtle trail effects, which can add a nice touch to your shot.

Editing Bulb Mode Shots in Luminar Neo

Long exposure images often come out looking a little flat straight out of camera. That’s because the extended shutter smooths out both highlights and shadows. This is where editing comes in.

One of the most useful tools in Luminar Neo for this is Supercontrast.

It allows you to work independently on highlights, midtones, and shadows, giving you much more control than a standard contrast slider. You can bring depth back into the image by strengthening the midtones and shadows, while also recovering detail in the highlights. It’s a much more refined way of rebuilding contrast.

The Structure tool is also very effective.

Used carefully, it can add clarity and detail back into your scene, which works especially well for urban shots.

For landscapes, you can take it a step further by masking specific areas. For example, select the water and reduce structure to soften it even more, while keeping the surrounding elements sharp. This contrast enhances the overall look.

If you notice noise from longer exposures, Noiseless AI can clean it up while preserving detail, which is particularly useful for night scenes.

The Bottom Line

Bulb mode isn’t the most commonly used setting on your camera, but it has clear advantages in the right situations. It’s often avoided simply because it sounds more complicated than it actually is. In reality, all you’re doing is taking full control of your shutter speed by deciding exactly how long the exposure lasts.

For traffic trails, reflections, long exposures in low light, and smoothing motion in landscapes, it’s an incredibly useful tool.

So the next time you find yourself limited by that 30-second cap, switch over to bulb mode and take control of the shot.