Sony has produced what can be described as a camera game changer with its current flagship phone, the Sony a1. Although the camera offers a lot of new features that most of the reviews rave about. One of its most notable features has been dropped a bit. This feature is to increase flash sync speed to 1/400 second shutter speed.
The Sony a1 is one of the best full-frame mirrorless cameras on the market. Not only can it capture high-resolution 50-megapixel files, but it can also shoot at this high resolution at 30fps. Until recently, we thought speed and high resolution were an impossible combination, given current technology. You can have a high resolution camera that captures a lot of detail, or you can have a low resolution camera that shoots extremely fast for those high speed situations. Sony has managed to do both in one camera.
Additionally, Sony also managed to cram 8K 30p and 4K 120p in 4:2:2, 10-bit recording. Basically, the Sony a1 is an incredible camera system. However, these features are the obvious and inevitable upgrade in the grand scheme of things. Almost everyone expected Sony to produce an 8K-capable camera system, however, I didn’t expect anyone to think that Sony would improve the shutter mechanism and sync speed in the Sony a1.
What is a focal plane shutter?
The focal plane shutter is essentially the shutter mechanism found in most DSLRs and mirrorless cameras. A focal plane shutter exists in the camera and is located in front of the camera sensor. There are two parts to the focal plane shutter and they are called the first and second curtain.
The first curtain will drop to reveal the full sensor, then the second curtain will drop to close the shutters. The time it takes for the shutter to open and close depends on your shutter speed.
The main advantage of focal plane shutters is that they can manage shutter speeds faster than the leaf shutter mechanism (discussed below). Most high-end DSLRs and mirrorless cameras can manage shutter speeds up to 1/8000 second, significantly faster than leaf shutter cameras.
Another advantage of focal plane shutters is that they work in-camera. This means that almost any type of lens can be attached and the shutter mechanism can still function. You can even use the pinhole body cap on the camera and the shutter will still activate allowing you to expose the image.
The downside is that the focal plane shutter can only open fully at a certain speed. For most cameras, this shutter speed is 1/200 second. Above this speed, the shutter blades will no longer open fully as it moves down the sensor to expose the image. The shutter opening becomes smaller as you increase the shutter speed. This shouldn’t be a big deal unless you’re shooting with flash. If the aperture of the shutter is smaller than the sensor, the entire sensor will not be exposed when the flash is fired.
As you can see in the comparison above, a large portion of the flash will hit the shutter rather than the sensor when shooting faster than the sync speed. To work around this, you can use a feature called high-speed sync. In this mode, the flash fires several times rapidly, to follow the shutters as they move along the sensor. Unfortunately, this feature significantly reduces flash output making it less than ideal in many situations.
What is a leaf shutter?
Leaf shutters are relatively rare when it comes to camera systems. The biggest and most obvious difference between a leaf shutter and a focal plane shutter is that the leaf shutter works inside the lens instead of the camera. This greatly limits third-party compatibility. Another obvious difference is the construction of the leaf shutter.
The focal plane shutter moves over the sensor in one direction, usually from top to bottom. Leaf shutters open and close in a circular motion similar to how aperture blades are opened and closed. It is this design difference that makes the biggest difference. Unlike the focal plane shutter, the leaf shutter mechanism has no limit on flash sync speed. The leaf shutter lens can synchronize with the flash at any shutter speed it can manage.
For example, current Hasselblad lenses can synchronize flash even at a shutter speed of 1/2000 second without any kind of high-speed sync mode. The downside of leaf shutters is that the highest speed available is 1/2000 s and is considerably lower than what focal plane shutters can achieve, which is 1/8000s.
How has Sony managed this?
The camera’s shutter mechanism usually works with a spring-loaded system. In a focal plane shutter camera, the two curtains are loaded and then lit when you press the shutter button. Spring systems have worked extremely well in cameras for decades. However, this system has not been updated for a long time.
The Sony a1 comes with a dual control focal plane shutter. The shutter mechanism in this camera works with both a spring loaded and a magnetic system. The spring-loaded system will work at most fast and slow shutter speeds. The magnetic system only works between the shutter speed 1/320 s and 1/400 s.
These are the two fastest points where the Sony a1 can sync flash in full-frame mode. The magnetic system allows the shutters to move faster across the frame. The first curtain can open quickly enough that by the time the second curtain is ready to close, the full sensor will open for exposure.
This is the main difference. The magnetic system can move the shutters faster than the standard mechanism. That extra speed helps ensure the entire sensor is open for exposure instead of the parts blocked by the shutters.
Why is this a big update
The Sony a1 is the only full-frame camera on the market today that can sync with flash at a shutter speed of 1/400 second. This is twice the speed of most full-frame cameras, including top systems from Canon and Nikon. This sync speed can be further increased to a 1/500 second shutter if you shoot in APS-C mode. This type of speed is on par with some leaf shutter lenses.
Interestingly, even with this higher sync speed in the Sony a1, the camera’s shutter is durable enough to manage over 500,000 cycles. Though it’s important to mention that Sony has not disclosed durability ratings for the shutter mechanism when flash sync priority is enabled.
However, for many working photographers, this increase in sync speed offers more real-world benefits than improved dynamic range or increased resolution.
Having multiple resolutions can be great, however, after a certain point, a few more pixels make very little difference to how you shoot and the results you produce. Even with dynamic range, most cameras these days offer enough flexibility that stopping by half doesn’t make much or any difference to the workflow. Features like megapixels and dynamic range can make for great headlines, but in the grand scheme of things, that’s just marketing. Even smartphones can now take photos of up to 100 megapixels and higher.
The increase in sync speed makes a real change to the workflow. You can shoot at a higher shutter speed no matter what type of flash you are using. You can also delay the need to shoot with high-speed sync by stopping completely. This is especially useful when shooting in controlled or studio-based environments.
For a long time, if you shoot in the studio, the maximum shutter speed you can choose is 1/200 second. Being able to shoot at a faster shutter speed in a controlled environment can greatly reduce potential problems. If you’re taking pictures of people, for example, introducing motion into your photos is less likely to cause motion blur.
This is without a doubt one of the best and most unattainable leaps in technology we’ve seen in a long time, and Sony should be celebrated for making it.
Epilogue
This is a huge step forward for working professionals, and the best part is that it won’t be too long before this feature starts to appear on less expensive cameras. As the cost of features becomes less expensive, we may start to see this become the standard sync speed for flash.
At the moment it is not clear if Sony can develop this dual control mechanism further. It’s fair to assume that the magnetic system can manage even faster shutter speeds. However, perhaps durability concerns have limited the sync speed to 1/400 of a second.
Hopefully we’re just at the beginning of what’s possible with magnetic roller shutter drives. Who knows, Sony’s next flagship camera might even sync flash at 1/1000th of a second.
