# What Is Bulb Mode in Photography? **By Chanuka Nayanajith** · 2026-10-26 **Bulb Mode is a camera setting that lets you control exactly how long a long exposure lasts.** Instead of selecting a fixed shutter speed, you start the exposure and end it yourself, usually with a remote release or a built-in Bulb timer. It is especially useful for exposures beyond your camera's longest normal timed setting, such as 45-second cityscapes, several-minute seascapes, and carefully timed fireworks. You do not need Bulb Mode for every night photo. The aim is to choose the exposure duration that records the movement and light you want without losing important detail. This guide explains when to use it, how to set it up, and what to check when your results are blurry, noisy, or too bright. ## What Is Bulb Mode in Photography? In a normal exposure, you select a shutter speed, such as 1/125 second, 5 seconds, or 30 seconds, and the camera ends the exposure at that time. In Bulb Mode, the exposure continues while the shutter control is held open. Depending on the camera and remote, you may be able to press once to start and again to stop, or program a specific duration with a Bulb timer. The name comes from early cable releases operated by squeezing a rubber air bulb. Today's cameras may display **B** or **BULB** on the shutter-speed setting or have a dedicated Bulb exposure mode. The exact route differs between models. Sony's [Bulb photography instructions](https://www.sony.com/electronics/support/articles/00267933), for example, describe selecting BULB beyond 30 seconds in Manual mode on compatible cameras. Bulb Mode changes the **length of exposure**; it does not automatically choose the correct aperture, ISO, focus, or exposure time for your subject. Longer is not always better: lights can clip, moving subjects can disappear into blur, and very long captures can develop additional image noise. To understand the underlying relationship, start with our [guide to shutter speed in photography](/blogs/shutter-speed/what-is-shutter-speed-in-photography). ## When Should You Use Bulb Mode? - **Night cityscapes and traffic:** Try several seconds to around a minute to turn moving headlights into continuous light trails. Use Bulb when a longer or precisely timed exposure is needed. - **Waterfalls, clouds, and seascapes:** Exposures of tens of seconds to several minutes can smooth motion while stationary rocks or buildings remain sharp. In daylight, an ND filter may be essential. For shorter starting exposures, see our [slow-shutter water photography guide](/blogs/motion/how-to-create-silky-water-with-a-slow-shutter-speed). - **Fireworks:** Open just before a burst and end the exposure after its trails develop. Several seconds may be enough; keeping the exposure open too long can wash out overlapping bursts. - **Light painting:** Use a flashlight or LED to illuminate a stationary subject in sections or draw deliberate light patterns during one exposure. - **Star trails:** A long exposure can record apparent star movement, but you can also stack multiple shorter exposures to manage noise and reduce the risk of losing an entire lengthy capture. Nikon explains this approach in its [star-trail photography guide](https://www.nikonusa.com/learn-and-explore/c/tips-and-techniques/photographing-the-night-sky-star-trails). **Important distinction:** Photographing the Milky Way as distinct, relatively sharp stars usually requires a much shorter exposure, often in the range of seconds rather than minutes, depending on focal length, camera resolution, and acceptable trailing. A very long Bulb exposure on a fixed tripod will generally turn stars into trails. Tracked astrophotography is a different setup. Lightning can also be photographed with timed or Bulb exposures from an appropriately protected position. Never remain outside to operate a tripod during a thunderstorm: the [US National Weather Service's lightning guidance](https://www.weather.gov/safety/lightning-tips) advises moving to safe shelter when thunder is heard. ## Gear for Sharp Long Exposures - **Stable tripod:** A rigid tripod on firm ground helps prevent camera movement throughout the exposure. Avoid positioning it where waves, vehicles, or people may strike it. - **Remote shutter release or Bulb timer:** Use a compatible cable, wireless remote, or built-in timer so you do not have to hold the camera's shutter button down. Check that your chosen device supports your camera's Bulb behavior. - **ND filter:** A neutral-density filter reduces incoming light so you can make long exposures in bright conditions without overexposing the scene. - **Spare battery and weather protection:** A lengthy exposure consumes power; cold weather and repeated review can shorten shooting time. A lens heater can help control dew on cold, humid nights. - **Small flashlight:** A red-light headlamp is useful for adjusting equipment while preserving more of your night vision. ## How to Use Bulb Mode: Step by Step 1. **Choose a suitable scene.** Begin with a stationary night skyline or a quiet road seen from a safe, stable vantage point. Set up your tripod, compose the scene, and make sure the camera cannot move in the wind. 2. **Find BULB on your camera.** On many cameras, select Manual (M) and turn the shutter-speed dial past the longest timed exposure until BULB appears. Other cameras have a separate B mode. If the option is missing, check the user manual and confirm that the selected shutter type and drive mode support Bulb shooting. 3. **Choose aperture and ISO for the subject.** For a stationary cityscape, try a low native ISO and an aperture around f/5.6 to f/8, adjusting for depth of field and lens sharpness. ISO 100 or 200 is a reasonable starting point on many cameras, not a rule. For dark skies with pinpoint stars, a wider aperture and a higher ISO may be more appropriate. 4. **Focus carefully.** Autofocus may struggle in darkness. Aim at a clearly defined distant light, magnify the live view if available, adjust focus, then switch to manual focus or otherwise lock it before starting the long exposure. Recheck after changing focal length or moving the camera. 5. **Estimate the exposure time.** Take a shorter test photograph at the same aperture and ISO. Inspect its brightness and highlight detail, then calculate or adjust the intended longer exposure. If using an ND filter, account for the filter's light reduction as shown below. 6. **Start the exposure without touching the camera.** Trigger the remote or timer. Time the exposure using a remote display, camera timer, or stopwatch. On the Sony Alpha 7 V, for example, the [built-in Bulb timer](https://helpguide.sony.net/ilc/2540/v1/en/contents/211h_bulb_timer.html) can be set from 2 to 900 seconds in one-second increments. Stop the exposure at the planned duration if the timer does not stop it automatically, then let the camera finish saving the file and any enabled noise reduction. 7. **Review and refine.** Inspect sharp details at high magnification and check bright signs, lamps, and other highlights. Shorten the next exposure if important highlights are washed out; lengthen it cautiously if the scene is too dark and the highlights allow it. ## How to Calculate Bulb Exposure Time with an ND Filter An ND filter is useful when a normal exposure is too short to blur water or clouds. Each additional stop of ND light reduction requires approximately twice the exposure time to maintain the same recorded brightness, assuming the aperture, ISO, and lighting stay unchanged. **Exposure time with ND filter = metered time without filter × 2 to the power of the filter's stop rating.** For example, suppose the camera meters **1/15 second** at f/8 and ISO 100 without an ND filter. Add a **10-stop ND filter** and the calculated time becomes 1/15 × 1,024 = approximately **68 seconds**. This is a sensible Bulb starting point if the camera's regular shutter-speed range does not reach it. This calculation is an estimate. Filter strength may differ slightly from its label, and light can change during the exposure. Make a test image and adjust. If your camera can time 68 seconds directly, you may not need Bulb Mode at all. ## Common Bulb Mode Problems and Fixes ### BULB Is Missing or Disabled Check Manual or B exposure mode, then examine your shutter and drive settings. Some cameras disable Bulb with a fully electronic shutter, silent shooting, continuous shooting, or certain bracketing modes. For example, Sony's [Alpha 7 V Bulb shooting guide](https://helpguide.sony.net/ilc/2540/v1/en/contents/0302C_bulb.html) lists the electronic shutter, continuous shooting, certain bracketing modes, interval shooting, and Silent Mode as incompatible settings. Single shooting with the mechanical shutter supports Bulb on this camera. These restrictions vary, so use the guide for your exact model. ### The Photo Is Blurry Look for tripod movement, an unstable surface, a loose tripod head, inaccurate focus, or wind. Use a remote or timer, and keep unnecessary contact with the camera to a minimum. Remember that stationary subjects can be sharp while cars, waves, branches, and people blur by design. ### The Photo Is Too Bright or Has Blown Highlights End the exposure sooner, lower the ISO if it is above an appropriate native setting, or use an ND filter when practical. Bright fireworks, streetlights, and signs can clip while the surrounding scene remains dark. A shorter exposure or a separate bracketed frame may preserve more highlight detail. ### Color Speckles or Hot Pixels Appear Very long exposures can make thermal noise and hot pixels more noticeable. If your camera offers **Long Exposure Noise Reduction**, it may capture a second dark frame to help reduce fixed-pattern artifacts. That process can keep the camera busy for about as long as the original exposure. Sony [documents this extra processing time](https://helpguide.sony.net/ilc/2540/v1/en/contents/0414_long_exposure_nr.html) for the Alpha 7 V. For repeated star-trail images, shorter frames stacked later may be more practical than a single extremely long exposure. ## Editing Bulb Mode Photos in Lightroom When possible, capture RAW files so you have more flexibility when balancing bright lights, deep shadows, and changing color temperatures. Begin with exposure and white balance; check highlights before lifting shadows. Apply luminance and color noise reduction only as needed, reviewing sky detail and building edges at 100% magnification. Heavy noise reduction can smear faint stars and fine textures, while excessive sharpening can emphasize grain. For night cityscapes, AAAPresets' [AI-Optimized Night Photography Lightroom Presets](/products/ai-optimized-night-photography-lightroom-presets) offers eight adjustable night-photo looks supplied in XMP and DNG formats for supported Lightroom and Adobe Camera Raw workflows. Use a preset as a creative starting point, then refine exposure, highlights, shadows, and color for the individual file. A preset cannot restore completely clipped lights, remove severe camera shake, or replace a properly focused exposure. ## Start with One Controlled Long Exposure Bulb Mode is most useful when you need a duration your camera cannot time normally or want to control exactly when an exposure ends. Begin with a steady tripod, a remote or timer, and one predictable subject. Make a test frame, calculate the next duration, and compare your results. After you can reliably capture a sharp 45- to 90-second image, experimenting with light trails, smooth water, and longer night scenes becomes much easier. Written by [Asanka Dilshan](/pages/about-us), founder of AAAPresets. **Tags:** Bulb, Bulb Mode, Camera Modes, Camera Settings, Long Exposure Photography, Manual Mode, Night Photography, Photography, Photography Basics, Shutter Speed --- > Source: [aaapresets](https://aaapresets.com/blogs/manual-mode-camera-modes/what-is-bulb-mode-in-photography)