Your camera is so full of settings that it often takes years for most amateur photographers to figure them all out. One of those is bulb mode. It's hidden deep within the recesses of your camera's shutter speed settings, and it can help you take some amazing pictures of the stars at night. In this short tutorial, we’ll have a look at bulb mode, what it is, and what it’s used for.
Your camera contains two components that do the bulk of the work when you take a picture. The lens focuses the light, and the shutter opens to let the light in. In this tutorial, we’ll be talking about the shutter. Bulb mode is a certain way of controlling your camera’s shutter. We’ll get to that in a moment. For the time being, we need to learn a little more about shutter speeds.
When your camera takes a picture, it usually opens the shutter for a fraction of a second to let the light in. In most situations, that’s all the light you’ll ever need. People generally take pictures during the day. The sun is so bright that if you were to keep the shutter open for as much as a second, the resulting image would be completely white. That’s why we typically use shutter speeds that measure in fractions of a second. During the day, we often shoot at 1/500s to 1/125s.
When taking pictures at night, the shutter needs to stay open longer
Night time is completely different. The amount of light available is dramatically reduced. Without the sun to aid you, you need to keep the shutter open a lot longer. Otherwise, the resulting image will be completely black. When taking pictures at night, most photographers use shutter speeds that measure in seconds, not fractions of a second. More time is equivalent to more light, so when you lack light, you can almost always compensate by keeping the shutter open longer.
Most night time images are taken at shutter speeds somewhere between one second and 30 seconds. That’s usually enough time to capture the light from cars moving by, the light reflected off of buildings from street lamps, or in some cases, the reflected light from the moon.
How bulb mode can help you achieve longer exposures.
Sometimes 30 seconds just isn’t enough. Sometimes you need to keep the shutter open for minutes or hours at a time. That’s where bulb mode comes in handy. Once you switch your camera over to bulb mode, you simply press the shutter button once to open the shutter, and then you press it again to close the shutter. The duration of the exposure is completely up to you.
You might want to use bulb mode when you only have starlight to work with. The stars, although bright, are also very far away. They may fill up the sky, but they don’t illuminate subjects very well. Oftentimes, you’ll have to wait at least half an hour to get an exposure that’s bright enough to see any colors. In that case, you have no other choice but to use bulb mode.
It all depends on the amount of ambient light available. Cities are generally brighter at night than the countryside, so you might not need to use bulb mode when you’re in an urban area. The only way to truly know is through experimentation. If you can’t get a detailed exposure with your shutter speed set to 30 seconds, then you’ll need to start playing around with bulb mode.
On a side note, you can achieve some pretty awesome effects with bulb mode. The picture to the right, and at the top was taken with bulb mode. The shutter was open so long that it captured the movement of the stars across the sky as arcing streaks of light. Just make sure you use a tripod, and the scene will be still enough for you and your viewers to see the details.
Where can you find bulb mode?
To access bulb mode, you need to decrease your shutter speed to its lowest possible setting. Once you’ve gone past 30 seconds, your camera’s LCD should say “bulb” as your shutter speed. None of this is possible, however, if you don’t set your shooting mode to "manual" or "shutter priority" You need to be able to control your shutter speed in order to shoot in bulb mode. No automatic settings are allowed.
Be aware that bulb mode, depending on your camera, can drain the batteries. Always bring a fresh battery with you on those long nighttime photography sessions, or you’ll be coming home sorry after you’ve just wasted 20 minutes attempting to take a picture. In some cases, the length of your exposure can be completely determined by the extent to which your camera drains the battery in bulb mode. To get a longer exposure, you might need a new camera or a bigger battery.
Let’s hope it doesn’t come to that. If you have any more questions about bulb mode and super extended exposures, let me know by leaving a comment below or sending me an email. I’d also love to see the results of some of your experiments with bulb mode.
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