Putting a camera on a tripod, even if the ball head is loose, removes four of those six degrees of freedom making it significantly easier to get a steady shot. It can move in any of three directions and rotate about any of those same three axes. In the hands, a camera has six different degrees of freedom. Tripod and BracingĪ tripod can also limit motion, even if it’s not locked all the way down (bracing works in a similar manner). Leaving the shutter release in continuous high-speed mode can make it easy to knock off three or four images in quick succession. Taking multiple images often allows you to come away with a keeper or two at a slower shutter speed than is possible to pull off reliably with a single shot. Since camera shake tends to be random, there will often be some times when the camera is moving less than others. I’ll usually do the experiment completely handheld as well as with my elbows braced on something to see what ratio of keepers is achievable at each shutter speed. The results can inform decisions you later make in the field. Try shooting at a wide range of different shutter speeds, taking three or four shots at each with the vibration reduction system engaged. Many lenses and camera bodies also have vibration compensation elements built into them that can add 3-5 stops to the effective shutter speed range. That depends on a number of factors, though: how much coffee you’ve had, the resolution of the camera sensor, whether you’re shooting from steady ground or a moving boat, etc. One of the first rules of thumb one often learns when taking up photography is to use a shutter speed at least as fast as one over the focal length of the lens, e.g., for a 300mm lens, you’d likely want to use at least 1/300th of a second. Since the root cause is closely related to subject motion, one of the solutions is also the same: increasing the shutter speed. Examples of each are highlighted in the image above. Edges perpendicular to the direction of motion, however, tend to undergo obvious blurring as the colors on opposite sides of the edge are smeared into one another. In general, edges parallel to the direction of shake tend to remain sharp and well-defined since the shift is across regions of roughly the same color/luminosity. The camera was moving roughly from the upper left of the image to the lower right while the shutter was open. The result imparts images with a characteristic appearance.Ĭamera shake typically blurs the resulting image asymmetrically. What Does This Loss of Sharpness Look Like?īecause of their similar roots, camera shake looks identical to motion blur, except that the whole field of view moves uniformly. In this case, though, it’s the camera body/lens that’s moving rather than the subject. The scene is moving relative to the sensor while the shutter is open. The question isn’t why can’t we hold a camera still? It’s how are we able to hold one as steady as we are?Īny residual motion in the process of steadying the camera has the potential to cause a loss of sharpness for the same reason that subject motion does.
Further, there are at least 36 different muscles that must be actuated to allow us to simultaneously control a camera’s six different degrees of positional and rotational freedom.
Trying to aim a camera involves complex feed-forward and feedback loops in the brain, integrating the visual system, motor cortex, and an intricate web of sensory neurons. The fundamental problem is a limit to how steady we can hold our hands. Camera Shake What Actually Causes the Loss of Sharpness? This week we’re going to look at two more: camera shake and depth of field. Last week, we looked at three common factors that can lead to a loss of image sharpness: the optical design/assembly of a lens, missed focus, and subject motion.
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