LED Constant vs. Flash: Differences And How to ChooseUpdated 20 days ago
Light comes from many different sources. In the realm of artificial lighting and visual media, LED and Flash (strobe) are our two main sources.
In this article, we will discuss the differences between the two and why you may consider one over the other.
Simplified: Pros and Cons
LED Constant
Pros
- Ease of Use: "What you see is what you get."
- Great for Hybrid Creators: Dual purpose for video and photography.
- Easy Color Control: Bi-color or RGB options are available without the use of filters or gels. More affordable LED lights will be one color, usually 5500k.
- No "Syncing" Required: With LEDs, you can turn them on and go, with no worry about syncing with multiple shooters and various equipment.
- Wireless control: Some units have Bluetooth features built in, allowing for remote control from a smart device.
Cons
- Power Consumption: Larger LED lights usually do not have built-in batteries. Extension cords, generators, or battery packs would have to be considered. And some battery packs limit the max power output when used.
- Power Production: When compared to flashes, LEDs lack power and may not be able to match exposures in bright scenes.
- Motion Blur: With stopping motion blur, you are limited by the shutter speed of your camera. Thus, you may need much more power than you expect.
- Heat Buildup: LEDs are much cooler than the traditional bulb kits, but heat can still build up over time, making modifiers and possibly your subject hot over time.
- Flicker risk: Lower quality LED lights may cause flickering or banding in your video at high shutter/frame rates.
Flash
Pros
- Size vs Power: Flashes pound for pound produce much more power than LED lights.
- "Cleaner" images: With the increased available power, you can use lower ISO values, resulting in less noise in your image.
- Freezing Motion: Because of the nature of flash and its flash duration, you can freeze motion easily, as if you are using fast shutter speeds. usually 1/1000 or higher.
- Power Consumption: Almost all FJ Wireless flashes include rechargeable batteries that allow you to charge while shooting as well. Allowing you to shoot anywhere, for hundreds or thousands of flashes.
- Easy Wireless Control: All FJ wireless flashes can be easily controlled and triggered using any of our triggers. Allowing individual control of each light wirelessly from your camera.
Cons
- Photography only: Flash pulses are often faster than typical video frame rates. This can cause half-illuminated frames in your video.
- Everything Needs to Sync: Flash pulses need to sync with your camera's shutter. Proper wireless designations, groups, camera settings, and firmware are required.
- One Shooter at a Time: Unless multiple triggers are used, only one person at a time can shoot with wireless flashes.
- Test Shots or Metering are Required: Since you can't see exactly how the photo is going to look through your camera or in person, you will have to either use a light meter to get your settings or take test shots to see how the light behaves. Modeling lights exist on the lights to assist in this, but do not replicate the end result faithfully.
- Photosensitivity: Flashes of light, especially rapid firing, can startle people and animals alike, especially if they are epileptic.
Choosing a Light Source
The light source you choose is dependent on many factors. What are you photographing? Are you limited in how you photograph? Are you a hybrid shooter? What is your comfort level and skill level with lighting?
Below are a few topics that can help you decide between LED (constant light) and flash.
- Video: If you’re shooting video, LED/constant light is usually the practical choice. Flash can fire during video, but it typically looks like a brief “pop” rather than usable continuous illumination. Depending on shutter angle/frame rate and timing, a strobe may not land cleanly on a frame or may appear inconsistent from frame to frame. Additionally, many LED lights have different effects like "flash" or "Lightning" built in and will look much more natural in your video.
- Photo: If you’re shooting still photos, you can use either LED/constant light or flash, so the choice comes down to the look you want and the conditions you’re in. Flash is often preferred when you need more power, want to freeze motion, use a lower ISO, or overpower ambient light (like bright windows or midday sun). It also gives you strong control over contrast and direction, even with larger modifiers. LED/constant light is great when you want a more natural, continuous feel, need to see your lighting changes in real time, or you’re working at a slower pace where you can fine-tune shadows and catchlights without test shots. It can also blend nicely with practicals and existing light for a more cinematic or ambient-heavy style.
- Hybrid Shooters (Photo + Video): If you offer both video and photo services, starting with LED/constant lights can be a smart move because the same lighting kit works for both. As your work grows and you want more power, more control, and easier motion-freezing, adding dedicated flash/strobes later is often the ideal upgrade.
- Stopping Motion: Flash has the advantage when freezing motion, which is due to the light output happening in a very short burst. With the right flash power settings, the flash duration can effectively freeze fast movement, sometimes far beyond what your camera’s max shutter speed can do. Constant light cannot do that on its own. If you want to freeze motion, you will need a very bright light (to allow very fast shutter speeds) and/or higher ISO, and any movement during the exposure can still register as blur.
- Matching or Overpowering Existing Light: Ambient light can range from a dim office to full midday sun. Flash is often easier to scale across that range because you can raise power and keep ISO low. Constant lights can struggle outdoors in bright sun unless you’re using very powerful fixtures (often expensive and bulky). High-powered strobes can compete with sunlight more practically, often without needing large continuous-power setups that can be uncomfortable for the subject.
- Comfort and Skill Level: If you’re new to lighting, starting with flash can feel like jumping into the deep end. Flash adds extra steps (triggering/sync, flash power, and balancing flash with ambient), and you usually evaluate the result after the shot.
With constant light, what you see is what you get, you can watch shadows move and exposure change in real time. Constant light doesn’t become useless once you buy flash. Using both together can create unique results, especially with slower shutter speeds, where the constant light can create motion blur or “dragged shutter” effects while the flash freezes the subject.
The good news: placement and shaping tools (modifiers, angles, distance, feathering) work similarly for both. Once you’re comfortable with those fundamentals, moving to Flash is much easier. With constant light, what you see is what you get, you can watch shadows move and exposure change in real time. - Photosensitive Subjects: If your subject is sensitive to bright light or sudden flashes, such as people with migraines, sensory sensitivities, certain medical conditions, or newborns, LED/constant light is often the safer, more comfortable choice because it avoids the sudden “pop” of a strobe. You can also keep the light dim and close, soften it with diffusion, and build exposure gradually so the subject can adjust.
That said, constant light can still be uncomfortable if it needs to be very bright (people may squint or tear up), so prioritize soft, indirect light: bounce it, diffuse it, and avoid aiming a bare light straight into the eyes. If you do use flash, consider making it as gentle as possible. Keep power lower and increase distance/ISO as needed. Warn the subject before firing and give breaks when needed. Ask ahead of time if the subject has any sensitivities, and default to the most comfortable setup that still achieves your goal.
Power Comparison
Flashes/strobes produce more power in smaller packages when compared to most LED lights. To help put things in perspective, let's compare the L120 and the FJ400 II using a light meter.
- With the L120 at 100% power, 5500k, the included reflector attached, one meter away from the light meter, to get a proper exposure, your camera's settings would be 1/125 - f/5.6 - ISO 100
- With the FJ400 II, to get the same exposure, under the same circumstances, the strobe would have to be set to power level 5, only 1/16th power.
In this example, the FJ400 II can still produce 4 stops or more power. Also, at power level 5, the FJ400 II naturally has the freezing power of a 1/3000 shutter speed due to its flash duration.