Understanding High Speed Sync – How to Blend Flash with Natural Light

High speed sync (HSS for short) is a feature that allows your camera to exceed the normal sync speed of the flash.

In this video, Kyle explains and demonstrates how using a flash unit outside can enhance your image and how best to use HSS. The final image is subjective to personal taste, and there is no right or wrong way to balance the two light sources, but if you’re looking to achieve something natural with a shallow depth of field, HSS is the best option.

HSS is available on our LINK and Celestial Units when used with the HUB remote.

We took our new Celestial flash unit outdoors to show you exactly how it works!

We’ll begin without using HSS. To start, Kyle advises to expose for the background first. Sync speed on his camera is 1/200, which means the aperture needs to be higher than he’d like to get a properly exposed background. As the sky and surrounding areas are properly exposed, the subject will likely be underexposed. This is when to add the flash unit and light the subject.

This balance of exposure between the background and the subject can lend itself to more natural results, as shown in the images below.

The image on the left is less natural, as Kyle has underexposed the background, and the subject pops more in the scene.

On the right, the background and subject are more balanced, and the use of flash is less noticeable, while still helping fill in shadows that harsh sun can create. These two images were created without using high speed sync, but in return he sacrificed being able to open up the aperture due to being restricted to the 1/200 shutter speed.

Now, let’s incorporate high speed sync.

Being able to exceed 1/200 shutter speed allows Kyle to use the widest aperture available on his lens, opening up to 1.2f.

As you can see, using a wider aperture produces a shallow depth of field as opposed to the images without HSS. Whichever your preference may be stylistically, utilizing HSS allows you to have freedom in your camera settings without having to worry about shutter speed.

In the particular shoot, the sky was overcast, so the use of flash wasn’t the most drastic difference and wasn’t completely necessary for a nice image, as the clouds were diffusing the light. Using flash in harsh sunlight is where you can really see the benefits. Below are some images he took with the same lens on a bright day.