What Is Bulb Mode? Where Is It Used? :: Digital Photo Secrets
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What Is Bulb Mode? Where Is It Used?

by David Peterson 49 comments

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.

Happy shooting!

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  1. Tony Parrish says:

    With the digital cameras, is there a time limit for holding the shutter open? The longer it's open does it damage the sensor? It sounds like it would be OK to leave the shutter open for say 6 hours but the limitation is the battery. Thanks for your help.

    • David Peterson says:

      Hi Tony,

      The battery is your only time limit. However, you quickly start to have problems with noise build-up.

      Are you looking to photograph a night sky? There are better ways than leaving your shutter open for 6 hours. Take multiple photos one after the other and then merge them together in an editing program to get the star trails. It's called image stacking.

      Here is a tutorial for image stacking: http://www.peachpit.com/articles/article.aspx?p=2135396

      I hope that helps.


  2. Dawn says:

    Thanks for the info David, that was just what I was hoping for.
    I can now get back to one of my favourite parts of this wonderful hobby.
    Your original article was also a great help.

  3. Dawn says:

    Hi David
    I have an EOS 1200D and have tried the bulb setting. However, the shutter only stays open for as long as you have your finger on the shutter release button. This also the case with the EOS 450D.
    Do you know if the remote for the 1200D allows you to keep the shutter open for as long as you want hands free, as I want to do some more astral and storm pictures and need to keep the shutter open for long periods.
    Thanks for your help.

    • David Peterson says:

      Hi Dawn,

      The cheaper Canon cameras will always only keep the shutter open while you keep the shutter button pressed. There is no way to change the operation to be one press for open, and a second press for close.

      However, most of the remote shutter releases (like the Canon Rs-60e3) have a shutter lock that you can enable to keep the shutter open for an extended period of time.

      I hope that helps.


  4. Tyler says:

    I have my canon 5d Mark III in "manual mode" and when I try to slow the shutter speed below 30 seconds should it not then switch to "bulb"? Or do I have to actually have to turn the mode dial to bulb if I want to go past 30 seconds?

    • David Peterson says:

      Hi Tyler,

      It depends on the camera. Some switch to bulb mode if you change the shutter speed past 30 seconds. Others you need to specifically set bulb mode. On your Canon, you'll need to specifically set Bulb Mode which will keep the shutter open while you hold the button down.


  5. Kami says:

    Great explanation of the Bulb mode...thank you! Now I actually understand it! Hopefully, I can get away from the city lights some place where I can use the setting? Also, is the 'Time' setting on my Nikon similar to the 'Bulb' mode?

    Off the topic... But in your opinion, is it better to buy a filter with a range of ND numbers (where you can dial in the density) or buy single filters with fixed density? Also, what do you think of graduated neutral density filters? Is the usefullness of the graduated filter limited? I am a 'newbie' and don't want to spend major $$$s. Thanks!

    • David Peterson says:

      Hi Kami

      Great to hear!

      There are a few different names for 'bulb' mode, and there are other modes that allow you to keep the shutter open for a long (but still set) time. You don't tell me what model you have, so I can't tell you exactly what the modes do. Check the manual for your specific model for more help.

      Regarding ND filters, the filters with a range of ND densities usually do it by stacking filters on top of each other. That works to reduce the light into your camera, but it also means there is more glass between your camera and the scene which can cause problems with the image.

      If you have the funds, I recommend going for the single filters with a fixed density.

      A graduated ND filter is useful for landscapes close to sunrise/sunset with a bright sky and a dark land. Unless you're doing a lot of this photography, I would not recommend a graduated filter.

      I wrote an article discussing the different ND filters here: http://www.digital-photo-secrets.com/tip/2073/when-and-how-to-use-a-neutral-density-filter/

      I hope that helps.


      • Kami says:

        Great tips David! And VERY informative article on neutral density filters! Thank you!

        At the risk of sounding 'stupid', how do I find out what the range of the 'density' in a graduated density filter? I live in Southern California and with the ocean just a few miles from me, I might find having a graduated filter useful.

        Also, do you have any articles on 'panning'-very basic explanation?


  6. Mitika Nagpal says:

    hi...i m just wondering if i can use bulb mode for newborn photography as i dont have any external light source for shooting at home. plz reply

    • David Peterson says:


      I would not use bulb mode for photographing anything that can move.. including babies. In your situation, it might be worth increasing the ISO to make the camera more sensitive to light. Increase the ISO until you can take a correctly exposed shot with the shutter speed at 1/50 sec (or faster).

      I hope that helps.


  7. Lyeo says:

    Hi David, does bulb mode works for shooting northern light? Just wondering, what's the difference between 'bulb' and 'time'? I tried both and the picture does not look any different to me.

    Thanks for the greate article, it helps me to understand more about bulb mode.

    • David Peterson says:

      Hi Lyeo,

      They are almost identical. On most cameras, in 'bulb' mode you need to keep the shutter button held down to keep the shutter open. In 'time' mode, you press the shutter button once to open the shutter, and a second time to close the shutter. Other than that, there is no difference.

      I hope that helps.


  8. Steve says:

    Hi David,

    Great article! I'm a newbie, but have def caught the shutter 'bug' and found this very helpful. My question is, "What is the best way to create a mist effect or capture waves crashing over rocks during a storm?" I tried bulb, but got nothing but a whiteout.
    Steve :)

  9. Ahmed says:

    While using the bulb function it gives me subject is too dark and the shutter not released !!

    • David Peterson says:

      Hi Ahmed,

      What's probably happening is your camera isn't able to get a focus lock on your subject so won't allow you to open the shutter. Use a portable light (like a torch) to illuminate your subject first then set the focus point by half pressing the shutter. Then switch to manual focus mode and take the photo with bulb mode.


  10. irina says:

    Hi David,

    i have Nikon 3200. Into bulb mode I got by accident and now i don't know how to get rid of it. i can control shutters myself up to 30". After that the setting automatically goes to Bulb mode. Any suggestions on how to fix the situation?

    • David Peterson says:

      Hi Irina,

      That's the way your camera works. You can change the shutter speed up to 30 seconds, then the camera switches to Bulb Mode so you can control directly how long to keep the shutter open for.

      I hope that helps.


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