PocketWizard HyperSync – Warp Speed for Studio Strobes
Recently we have really been focusing on using speedlites due to their flexibility and features like high speed sync. We usually donâ€™t take our studio strobes out of the studio because with a maximum sync speed of about 1/250th of a second, we usually canâ€™t get the shutter speed fast enough to keep the sky from blowing out. While we can sometimes compensate by closing down the aperture and kicking up the power on the strobe we then lose control over our depth of field. With high speed sync, we can use a fast enough shutter speed to keep our sky nice and blue while given us the choice of aperture to use. So why doesnâ€™t this work with studio strobes and how can we create a workaround? Continue reading for more information.
A simplified explanation of how a shutter works
First we need to understand how a shutter works in order to understand why we canâ€™t use high shutter speeds with a studio strobe. Many of you have heard of first and second curtain for front and rear curtain but what exactly does this mean? Many people think that when you press the shutter release button that the shutter flips open and then flips back down.
What actually happens is that there are two components to the shutter, when you press the shutter the first shutter slides up out of the way and exposes the sensor. When the shutter speed time expires, the second shutter (curtain) slides up and covers the sensor. Up to certain speeds (1/160 – 1/250 depending on camera) the entire sensor is exposed. So when a flash goes off, the light is picked up across the entire sensor all at once.
At speeds higher than the standard sync speed, the second curtain is closing before the first curtain is completely out of the way. When you fire a flash at these speeds, the entire sensor is not exposed and you end up with black banding issues.
High speed sync solves this by firing a continuous stream of thousands of small strobe burst essentially creating a constant light source while the opening between the two curtains slides across the face of the sensor.
High speed sync is not available with studio strobes because they cannot communicate with the camera and are not capable of firing small bursts for the same type of effect.
Is there a solution?
Wellâ€¦in a senseâ€¦there is. While we cannot make the flash do something it wasnâ€™t designed to do. Howeverâ€¦we may be able to pull a trick on the flash and trick it into firing at a different time in order to push it past the slower sync speed.
PocketWizardâ€™s ControlTL system has a unique feature called HyperSync. What HyperSync does in a nutshell is to fire the strobe before the shutter opens and the sensor is then exposed to the fading trail as the strobe bulb dims thus providing a pseudo-constant light. Since the initial flash occurs before the shutter opens this will definitely cut down on the output power by up to several stops. If your strobe dump very quickly, the fastest shutter speed may be limited while a strobe that dumps slower will have a longer tail allowing a wider range of shutter speeds.
How well does it work?
This is really going to depend on the combination of your camera body and your strobe units. In my testing I used Westcott StrobeLite Plus units with a Canon EOS 50D. Normally, this setup is used either with PC Sync cords or with Cactus V2 Wireless Remotes where the best I can get is a 1/250th shutter speed. As you can see from the first sample set, anything above 1/250th had severe banding problems.
With the MiniTT1 on the Canon 50D and a FlexTT5 connected to the Westcott StrobeLite Plus via a 1/8â€ mini plug cable, I started a battery of tests. First I had to make sure that 1/250 was still working properly which it was so I bumped the shutter to 1/500 and had no noticeable banding. I bumped it another notch to 1/640, still the same result, up to 1/1000 and still the same. At 1/1250 very noticeable banding appeared on the bottom of the frame but could easily get cropped out, by the time I got to 1/3000 the banding was was starting to get worse quickly although if you took into account it would happen, you can still get a good cropable image. At 1/4000th a bit too much of the image is banded. Still, this is absolutely amazing compared to what I was able to get before. After lots of additional testing and making sure the strobe was set to full power, I was able to squeeze even more out of HyperSync.
As you can see from the second sample set, there was no noticeable banding through 1/1250th. Bottom banding started showing at 1/1600th and 1/2000th but with a little cropping you can get perfectly usable shots. At 1/2500th we started getting vingetting at the top of the frame. This is without changing the aperture or ISO settings, so with a larger aperture and higher ISO I could force my way into higher shutter speeds.
Letâ€™s take a look at some comparison shots.
Sample Set 1 – Camera Connected to Strobelite via PC Sync Cable
Sample Set 2 – MiniTT1 on Camera, FlexTT5 Connected to Strobelite
Putting it to practical use
Ok, we have seen technically what HyperSync can do for us, but what are some practical examples of why we would want to use this technique? First off, we can use a high shutter speed to kill off ambient light. This allows us to completely alter the lighting on a subject regardless of the current conditions.
Here is a shot of lighting setup we used today at 3pm in the afternoon with the sun coming from very high and slightly to the left of the camera.
We positioned our subject on the seat and even though the sun is to the left, we are going to shoot with such a high shutter speed that the sunlight will be virtually non-existent and the flash to the right will become our key light.
By using HyperSync mode at 1/3200 of a second, even though we are using a standard studio strobe, we have no noticeable banding and we have made the side of the face that was in direct sunlight now become the shadowed side.Â Using these techniques you have total control over your lighting.
One complaint about studio lights is that you can’t run a fast enough shutter speed to freeze action, again this is where HyperSync can do magic for you. Take the following shot as an example, at the regular sync speed of 1/250th second, the fast moving drum sticks are just moving too fast for the shutter speed.
Even though we can still get some banding issues with HyperSync, they are very minimal. The following shots are the same image before and after some cropping.
As long as we are shooting with the understanding we will have some banding issues we can compose accordingly and still be able to get highly useful high speed shots.
While not everyone will need this kind of functionality, it is really good to know that it is there and if you are really looking for extra control of your lighting, sticking regular sync speeds just might not cut it for you. With PocketWizard’s HyperSync, your creativity is not limited by your shutter speed.
Equipment Used in this article
|Camera||Canon EOS 50D|
|Flash Triggers||PocketWizard MiniTT1 & Flex TT5|
|Lighting||Westcott SpeedLite Pro|
|Tripod||Vanguard 284CT & Manfrotto 322RC2 BallHead|
|Card Reader||Delkin eFilm Reader|
|Processing||Lightroom 3.0 Beta 2|
|Remote Power||Tronix Explorer XT|