The focal-plane shutter incorporated into most modern DSLRs is composed of two separate parts, the first curtain and the second curtain.

When you press the shutter release the first curtain opens and then the second curtain closes according to the selected shutter speed.

 

 

 

The time gap between the first and second curtain is the shutter speed.

For longer shutter speeds, like a one second shutter speed for example, the first curtain opens and the second curtain closes after the one-second time period has elapsed. In this case, the entire sensor is exposed to the light between the opening of the first curtain and the closing of the second curtain.

 

 

 

For shorter shutter speeds, like a 1/1000 second shutter speed, the first curtain starts to open and the second curtain follows shortly thereafter before the first curtain has made it’s way across the entire sensor.

This results in a narrow slit of light that moves over the sensor, thereby creating a very fast shutter speed.

Some medium format cameras have leaf shutters that are built into the lens, and which work differently than the vertical plane shutters in DSLRs. These shutters allow for higher flash sync speeds (in some cases up to 1/1,600 second) with no clipping.

This portrait of a fly-fisherman was captured with a Hasselblad H5D medium format digital camera using a leaf shutter, which can sync with flash at every shutter speed.

Medium format cameras have traditionally been the go to option when needing to sync with flash at high shutter speeds because they have a completely different shutter mechanism.

For wedding, fashion or portrait photographers, who generally have the flash close to their subject, HSS is an excellent option. The ELB 500 TTL is a perfect mix of power and portability with HSS and TTL technologies built-in.

This portrait of a whitewater kayaker was created using one Elinchrom ELB 500 battery-powered unit in HSS mode with the TTL engaged.

The beauty of HSS, and especially with TTL, is that you can quickly get an accurate exposure at any shutter speed and aperture setting and then move over to manual exposure flash mode and tweak the lighting as needed.

The HSS automatically compensates if you change your shutter speed.

The benefits of Hi-Sync include the ability to sync at shutter speeds above your normal sync speed, freeze motion, and the ability to overpower the sun from phenomenal distances. Hi-Sync can also be used to create a narrow depth of field using large apertures. Hi-Sync is fairly easy to use once you have it dialed in for your camera, though it is not as easy to use as HSS with TTL.

Hi-Sync is by far the best option for those who need the highest light output from their flash when shooting at shutter speeds above their flash sync speed. Hi-Sync also offers more options than any other flash technology because you have more light output at your disposal.

Because the ELB 400 and the ELB 1200 have multiple flash heads to choose from, and because the ELB 1200 has a Dock that turns it into a studio strobe, these two units are incredibly versatile.

Choose the right head.

For those jumping into HS with either of these kits, I recommend the HS and Action flash heads to have the ultimate versatility.

When using higher shutter speeds, like those above your normal flash sync—i.e. 1/400th second up to 1/8000th second, the HS flash head is the one to work with. When using shutter speeds at or below your normal flash sync shutter settings—i.e. 1/250th second down to 30 seconds, the Action head is then the preferred option because it has a very fast flash duration.

In the former case, the shutter speed will stop any motion and in the latter case, the fast flash duration will freeze the motion of the subject.

Hi-Sync uses much less power than HSS because the flash head is firing normally. With Hi-Sync it is also possible to turn the power down and continue to use a fast shutter speed. Hi-Sync offers more versatility than any other flash option on the market.