Cognisys High Speed Shutter - V2

The high speed shutter has just been put through a full redesign. The new version is smaller, lighter and features an integrated controller and improved durability. It also uses a bladed shutter instead of a solid shutter so it creates less vibration. The new shutter is still fully compatible with the Insect Rig and StopShot and uses the same adapter ring and filter sizes. It also operates on 12VDC for ease of use in the field away from AC power.

Most often high speed photography is done in a darkened room, the camera is in bulb mode with the camera shutter held open and a short duration of light from a high speed flash is used to expose the photograph. There are two significant reasons for shooting this way. The first is that a flash has a much shorter duration than your camera shutter is capable of. This allows you to freeze fast motion with less blur. The second reason is shutter lag. While flashes respond instantaneously to a trigger, cameras do not. If you try to trigger your camera to capture a high speed event it is very often the case that by the time the camera gets around to taking the image the event you were trying to photograph is over or out of frame. A good example of this is photographing insects in flight. The higher the magnification the smaller the field of view the more severe the issue. The high speed shutter offers a solution to the shutter lag problem.

If you have ever tried to capture a macro shot of an insect in flight you have probably fought against shutter lag. Shutter lag is the amount of time it takes between pushing the shutter button on your camera and when the camera actually captures the image. Modern DSLR and mirror-less cameras have a shutter lag between 35 and 300mS. This is way too long if you are trying to capture a close up shot of an insect in flight, by the time your camera gets around to taking the image your subject has moved out of frame. Enter the Cognisys High Speed Shutter. This shutter has less than a 10mS response time. It will allow you to capture even the fastest events without your subject moving out of frame.

When using the high speed shutter it is important to understand that it is used to get around the slow response time of the camera and improve the x-sync speed of the camera. The high speed shutter has an effective open time (x-sync speed) of about 1/300, most modern DSLRs have an x-sync speed of 1/200 or 1/250 best case. When using the high speed shutter it is important that your scene be completely illuminated by flash. When working in bright ambient light you will need to stop down significantly and use a low ISO to minimize the effect of the ambient light. The brighter the ambient light the more likely you are to see ghosting in your image. The reason for using the flash to freeze the motion is that you can achieve an effective shutter speed much faster than is possible with the camera shutter alone. The key to being able to illuminate your entire scene with flash is that camera sensor must be completely exposed all at once (with as fast an x-sync speed as possible). If the ambient light is too bright you may be better off using the fastest shutter speed your camera can deliver (usually around 1/8000) - the downside of this approach is the shutter lag is long and often the insect has left the frame by the time camera captures the image. 1/8000 s is often not fast enough to stop the wings of an insect in flight and is generally the max shutter speed that can used by the camera. It is all a trade off - the high speed shutter is another tool to give you more options.

Shown above is an image of the High Speed Shutter mounted to a 65mm MP E-65 macro lens extended to 2X. The shutter and controller are mounted on our Shutter Support System This whole assembly can be mounted on a tripod or on our Insect Rig.