Bulb mode photography (B setting on cameras) allows you to keep the shutter open for as long as you want while you’re depressing the shutter release button.
No idea why you would ever want to do that? You’re in luck. This article is all about using bulb mode to get better long exposures.
With modern cameras, we will use the Bulb setting when we want a longer exposure that exceeds 30 or 60 seconds. These limitations are set by the camera.
Use a Remote Shutter Release to Avoid Camera Shake
With bulb mode, you can hold down the camera shutter button for as long as you’re exposing. But this is neither comfortable nor great for sharp images.
There’s a high risk you’ll move the camera during shooting in bulb mode and end up with blurry photographs. This is why we recommend you use a remote shutter release when shooting in bulb exposure mode.
You can find anything from the cheapest cable release to the super advanced. These let you control your camera’s functions remotely.
Have a look at the Pluto Trigger. It’s a pretty advanced piece of tech. It even lets you decide how many photographs to shoot and how often to take them.
This can help you create time lapses, star trails,light painting and so on.
I photograph landscapes, seascapes, and starry night skies. Long exposures using bulb mode are a constant in my life. And I still use a cable remote shutter release I bought off Amazon for a few dollars.
Serves to show you don’t need the most expensive equipment for great photos.
It might not look like much, but it’s very sturdy and doesn’t need any extra batteries either.
Use a Tripod for Sharper Long Exposures
This is another indispensable accessory for sharp long and very long exposures using Bulb Mode.
I recommend as solid a tripod as you can afford, with legs that don’t vibrate at the first gust of wind. But this also depends on the environment you’re shooting in.
You don’t need the fanciest carbon fibre tripod if you’re photographing light trails in the city. But you will need it if you’re photographing a waterfall from the middle of a river with an exposure of 60 seconds or more.
Or if you want a crisp exposure of your scene during a two minute exposure in bulb mode off an ocean cliff.
Which Filters Do You Need For Bulb Mode
I use Bulb Mode to create landscape images with very long exposures. But you can also use this bulb mode for lightning photography.
Point your camera in the direction with the most lightning strikes, and start recording the exposure. Once the lightning strikes, stop the exposure.
For my purposes, I take pictures early in the morning before or during sunrise and in the afternoons, before or during sunset or the blue hour.
This means that I need neutral density filters. These allow me to stretch the shutter speed as desired.
For example, I have ND filters that increase the exposure time by 6, 8, and 10 stops.
Without any filter in front of the lens you have a shutter speed of half a second. But if you use an 8-stop ND filter, it will give you a shutter speed of 2 minutes and 8 seconds.
When using filters to keep shutter speeds longer, it is usually necessary to use a combination of other filters.
For landscapes, this means using a polarising filter as well. It will remove reflections from non-metallic surfaces and will saturate colours better.
Also GND or graduated filters may be fundamental to control the exposure and the histogram.
The polarising filter usually reduces the light amount by 0.7-1 stop compared to the base exposure. The GND filters can instead remove 1 to 4 or 5 light stops.
And then you have to add ND filters to lengthen your shutter speed.
How to Photograph Long Exposures in Bulb Mode
One of the main issues of bulb mode photography is that light changes during your exposure. Especially if you shoot bulb mode during the dawn or during the sunset.
Firstly, case light will increase very quickly as the sun rises from the horizon. Secondly, one you will be in complete dark in the round of 30 minutes.
This becomes a problem. Between the start of the shot and the end you could incur a major change in the amount of available light. Here, you find yourself with a ruined shot.
Or at least incorrect from the point of view of exposure.
What I tend to do as a landscape photographer is to take one or two shots with the Bulb Mode. This is after performing a series of test shots for the exposure.
When I am convinced of the exposure after checking the histogram, I start to calculate the final exposure.
To do this I use a smartphone app like PhotoPills.
After shooting, it is good practice to always check the histogram. The image you see on the camera screen is a low resolution and low quality version of the raw file.
The histogram instead is the faithful representation of the image. And it shows you the pixel distribution along the axis representing the brightness values.
Once you have adjusted the exposure the way you want it, add the CPL filter and the necessary GND filters. And once the histogram has the shape you want, adding the ND filter should only mean recalculating the shutter speed.
The final photograph should have a histogram like that of a basic test photograph.
Photography Composition for Bulb Mode
The other problem that you have to take into consideration concerns the composition. When you take long exposures with the Bulb Mode, bad compositions become more obvious.
You need to control the moving elements. This means clouds, rivers, water, waves in the sea, light trails, sun, moon, stars and so on.
Position the tripod and your camera. Next, set the focus point. Then set the polariser filter, along with its effect. Next, place the GND filters to control zones with different brightness.
In choosing your composition, you will also need to take into consideration the moving elements and their direction.
How to Reduce Noise in Bulb Mode Photography
In Bulb Mode, the sensor remains exposed to capture light for as long as you decide. So the prolonged exposure time will heat the sensor and the pixels of the sensor.
This will produce digital noise. Digital noise are all the little coloured spots in you image. Red and yellow micro-dots that will ruin your photo.
A small trick to get the cleanest raw files to edit in post-production is to apply long exposure noise reduction in camera.
It is a feature that all the modern DSLR and mirrorless cameras have. The camera, in a completely autonomous way, snaps a second frame with the shutter completely closed.
This second frame will last the same amount of time as the original one. This is called a dark frame.
At the end of this shot, the camera will drop what it considers to be digital noise produced by overheating the individual sensor sites.
I use it very often on my Olympus camera for exposures that last from thirty seconds to two or four minutes.
Remember though that to use the noise reduction on long exposures you will need twice the time you had budgeted.
I love long exposure photography. And over the years I learnt to love and to manage the Bulb mode in my cameras.
Now I can not do without the Bulb Mode technique.
This article is full of the tips and tricks I wish I had known many years ago when I started with landscape photography.
Now go out there and practice using bulb mode for your shots!
Looking for more tips? Why not check out our new post on how to understand exposure value next!