Flash duration is a term that often pops up in the world of photography, especially when it comes to capturing images that involve a lot of motion or require precise timing. Understanding flash duration, its significance, and how to manipulate it can transform your photography skills. In this article, I will decode the concept of flash duration and illustrate its importance in photography.
I am RayCee the Artist, a professional portrait photographer, event photographer, and wedding photographer, digital artist, and graphic designer, and if you would like to schedule a photoshoot with me or need me to create beautiful artwork and designs for you, please contact me at raycee@rayceeartist.com!
What is Flash Duration?
Flash duration, in its simplest terms, is the length of time that a flash emits light when fired. It's a measurement that tells us how quickly the light from the flash transitions from full power to complete darkness.
The faster the flash duration, the more desirable it is for photographers, especially those seeking to freeze motion in their images. In recent years, manufacturers have been emphasising fast flash duration as a key selling point of their products. However, it's essential to understand what flash durations actually signify, when you might need a fast flash duration, and how you may have been misinformed about this aspect.
The Functioning of a Flash
To understand flash duration better, lets delve a bit into how a flash works. The primary function of a flash is to discharge a significant amount of energy swiftly, recharge, and then release the energy again. The energy stored in the flash circuit's capacitors is responsible for this process.
Capacitors are perfect for a flash as they can release high amounts of power in short bursts, hence providing the necessary "pop" for the flash. Capacitors charge and discharge in a specific period. They don't discharge linearly - they release less energy as time progresses.
Why Flash Duration Matters?
Flash duration is a crucial factor for photographers who want to freeze motion in their images. When shooting in a pitch-black room (no ambient light) with a slow shutter speed (not in high speed sync), the flash duration effectively determines the exposure time of your photo. If the flash takes longer to turn on and off, a moving subject will appear blurred, and vice versa.
Understanding flash durations can open up new creative opportunities in photography. From capturing a dancer mid-leap, to photographing liquids or paint mid-flight, there are endless possibilities.
Different Measures: t0.5 vs. t0.1
Typically, flash manufacturers provide two values related to their flash durations: t0.5 and t0.1. These two terms represent different properties and measure flash duration. The t0.5 value measures the time it takes for the flash output to drop halfway (50%), while t0.1 measures the time it takes for the flash to drop to just 10% of the output.
It's important to note that the t0.5 time, which is more commonly provided by manufacturers, might not be as useful for photographers looking to freeze motion and avoid motion blur. This is because when the flash is at 50% power (the t0.5 time), it's still emitting a substantial amount of light that can impact your image. On the other hand, the t.01 of a flash will only be 10% of the original power, which is less likely to affect your image.
The Interplay of Power and Flash Duration
Interestingly, the flash power settings of your flash unit can influence the flash duration. Typically, a higher power setting yields a slower flash duration, and a lower power setting yields a faster flash duration. This is why pocket strobes, which are generally lower-powered than studio strobes, are often used for capturing fast-moving subjects like water droplets or paint splashes (they have faster flash durations at lower power).
The Role of Flash Duration in Freezing Motion
When it comes to freezing motion, the flash duration plays a more significant role than the shutter speed. This is because when a flash is involved, the speed at which it turns on and off determines how well the motion gets frozen. This makes understanding and manipulating flash duration vital for photographers who frequently work with fast-moving subjects.
Fast Flash Duration
A very fast flash duration (very short flash duration) is desirable for freezing motion. A very long flash duration is not desirable because that can introduce motion blur. In other words, the longer a flash is on, the more time there is for motion to be illuminated and introduced into a photograph.
The Importance of Accurate Flash Duration Times
Before purchasing a new flash unit, whether a studio strobe or pocket flash, it's beneficial to research and understand the t.01 times of the flash you are considering. Online resources, manufacturer's information, or third-party testing can provide this data. This information can ensure that you invest in equipment that meets your specific needs, especially if you aim to freeze motion in your images. Remember, fast flash durations are better than a short flash duration when you want to freeze movement.
Flash Duration Conclusion
Flash duration is a fundamental concept that photographers need to grasp to take control of their craft. While it might seem technical and complicated, understanding it can open up new avenues in photography, especially when it comes to capturing fast-moving subjects or freezing motion. So, the next time you're considering a purchase or playing around with your existing flash unit, remember to keep the concept of flash duration in mind.
I am RayCee the Artist, a professional portrait photographer, event photographer, and wedding photographer, digital artist, and graphic designer, and if you would like to schedule a photoshoot with me or need me to create beautiful artwork and designs for you, please contact me at raycee@rayceeartist.com!