Have you ever heard of Bulb Mode? Perhaps you have noticed that the maximum shutter speed in your camera is 30 seconds. Maybe you’ve even noticed that when you scroll the wheel just one step further your display shows the words Bulb or Time. But do you know what it means? This is actually a highly valued setting among landscape photographers, especially when photographing longer exposures.
What is Bulb Mode?
So, what is this beloved setting?
Like I just mentioned, the maximum allowed shutter speed in most DSLR cameras is 30 seconds. How is it then possible that photographers use shutter speeds of minutes or even hours? This is where Bulb Mode is so useful.
In simple words, this setting keeps the shutter open as long as the remote is triggered. (Obviously, pushing the trigger for minutes isn’t ideal but I’ll come back to how you can handle that in a moment.) Technically, as long as you’re pressing the trigger the camera is taking an image. Theoretically, this could be infinite but I doubt that the batteries or camera would last that long…
If you plan to use a shutter speed of 30 seconds or less, there’s no point in using Bulb Mode. Since the shutter speed will be longer than this you will be doing what is known as Long Exposure Photography. If you’re not familiar with this technique you should read our article Ultimate Guide to Long Exposure Photography before reading further as that article contains some essential information to taking this type of image.
How to Use Bulb Mode
It’s important to note that Bulb Mode is available only when photographing in Manual Mode. This means that the setting is not accessible in Auto Mode or any of the Semi-Automatic Modes. If this is your first venture into Manual Mode, welcome! There’s nothing to fear and you’ll get the hang of it soon. As a starting point when photographing landscapes use an aperture of somewhere between f/7.1 and f/11 and an ISO of 100. As for the shutter speed this depends on the situation you’re in.
Recommended Reading: Introduction to Fundamentals in Landscape Photography
Since we are working with exposures over 30 seconds there’s two requirements for this to work.
Use a tripod
Unless you are some sort of statue, I sincerely doubt you will able to hold the camera completely still for more than half a minute. A rule of thumb is to use a tripod whenever your shutter speed exceeds 1/60 seconds. This is to ensure as sharp of a result as possible.
The tripod doesn’t need to be the most expensive but I recommend buying something that’s durable. I’ve used enough cheap ones through the years to have seen that none of them has lasted more than a few months. We landscape photographers need something that can survive harsh conditions and not blow away when there’s a little wind.
Having a solid tripod is also important when we’re using exposure times of minutes. We want to minimise as much movement as possible and therefore we need the tripod to stand still and not be affected by a little wind or cars driving by.
So, when using Bulb Mode and photographing Long Exposures it is absolutely essential to use a tripod.
Use a Remote Shutter Release
I mentioned above that holding the camera’s shutter release for several minutes is a bad idea. As you might imagine, this will create a lot of movement on the camera and even though you think it isn’t that much, try zooming in; see how those details are being blurred out.
That is why another essential tool for using Bulb Mode is a remote shutter release. Unlike a tripod this does not need to be of high quality as we only need one simple function. Obviously, the more expensive models have functions that you might find useful but they are not essential.
One of the benefits of purchasing a medium- to high- priced remote shutter release is that they have a small display showing showing the time of your exposure, which can be very helpful when you’re taking exposures of many minutes. However, if you have a cheaper release there’s no problem in also using a timer on your phone.
When to Use Bulb Mode
If you’ve come this far, you now have an idea of when you should use Bulb Mode.
Since you’re only able to select shutter speeds of up to 30 seconds, this setting is intended for exposure times of more than half a minute. There’s no problem using Bulb Mode for shorter exposures but then it would be much easier to just select the desired shutter speed.
So, to summarize this topic: Bulb Mode is most commonly used for Long Exposure Photography. There are many scenarios when this technique is used such as star trails, night photography, seascapes, car trails etc.