We are going to talk about a really powerful – but occasionally misunderstood – flash tool called HSS, or High Speed Sync.
This feature allows us to achieve a proper flash exposure at a shutter speed much higher than the default flash synchronization speed. It’s absolutely brilliant and on many camera / flash combinations that support High Speed Sync, it’s often just a switch setting.
When we are looking to control the amount of light entering the camera and hitting the sensor, there are only so many things that we can do with our exposure controls. Being able to reduce the inbound light can open creative doors for us all. This is where neutral density filters come in.
We know by now that a camera lens does not focus at multiple distances at the same time. There is only one place that will be in perfect focus from the focal plane, and that is determined by where you focus the lens. When we focus a lens, there is only one focal plane to subject distance that is in perfect focus.
Yet we see that some areas in front of, and some areas behind our point of focus can also look sharp and that range can be different depending on some specific criteria. This zone that we perceive as being sharp versus the area that we perceive as being soft is what we are calling the “depth of focus”.