In this beginners guide to using high speed sync flash you’ll learn about simplifying this seemingly complicated technique.
Scenario: You’re at the beach snapping photos of your friend. The sunset is beautiful, so you want to include the bright sky in the background of the shot. The background look sort of cluttered, so you want to use a high aperture for a more ambient feel. For added action, you ask your friend to perform a cartwheel for the shot.
Problem: First, you focus the shot on your friend; the background darkens while your subject processes at normal exposure. Next you try focusing the shot on the background. You grow frustrated because the opposite happens; the background appears bright, vibrant, and sharp while your friend resembles a washed-out silhouette.
My guess is that you already know the answer to our problem. Properly using a high speed sync flash will allow you to capture dreamy, beautiful, and balanced portraits, despite these troubling lighting situations. Read on to learn more about this wonderful technique!
What exactly is high speed sync flash?
High speed sync flash is the ability of your camera to use flash at shutter speeds greater than the camera’s built-in sync.
Most cameras have a native sync of 1/120th of a second; anything faster than that will surpass the camera’s ability to sync the shutter with the flash. As a result, the shot will expose improperly.
One solution to the scenario above might be to lower the aperture. Unfortunately, this won’t allow the background to look how you want. Furthermore, your friend will most likely appear blurred because of the fast cartwheel movement.
Fortunately, a high speed sync flash will allow you to use a shutter speed that is faster than your camera’s native flash sync speed. Additionally, the special flash is more forgiving with aperture and will allow you to use a wider setting.
Both the sunset and your friend will be properly exposed, the cartwheel will appear sharp, and the background will look soft and blurred.
How does it work?
In short, a high speed sync flash causes the rear curtain of the shutter to begin closing before the front curtain fully opens. As a result, only a sliver of exposure moves across the image sensor. The flash fires during this sliver of exposure, causing the effect you are searching for.
How do I set it up?
Fortunately, this is the easy part. With a high speed sync flash- capable camera and a dedicated flash unit, all you have to do is set your camera to that setting.
What is the difference between “front sync” and “rear sync?”
The shutter of your camera consists of two distinct curtains: the front curtain and the rear curtain. When you take a photo at 1/500s, the front curtain of your shutter will open and the rear curtain will close after 1/500th of a second.
The default setting of the flash will most likely be “front curtain sync,” meaning the flash will fire when the front curtain begins to move. As a result, the subject is illuminated for the duration of the shutter speed.
Many DSLRs, on the other hand, offer “rear curtain sync.” This option causes the flash to fire right before the rear curtain begins to move.
By manipulating and experimenting with these settings, you can create different motion-blur and light stream effects, especially at longer shutter speeds. Natural ambient light is another wonderful effect of these options.
There you have it! Using a high speed sync flash (such as the bestselling models found here on Amazon) is simple, given you allow some room for experimentation.
In reality, the technique requires more knowledge about how the process works rather than practice with operating the technology itself.
So, my friend, go out there and take some wonderful sunset portraits on the beach!