What's actually going on in the lens of the camera to make VR a possibility?
2007-12-13 08:18:17 · 9 answers · asked by It's the hair 5 in Arts & Humanities ➔ Visual Arts ➔ Photography
There is a floating lens element within the lens [near the rear lens barrel] that is moved orthogonally, or relative to the optical axis of the lens using electromagnets. This movement is controlled by a circuit that monitors an accelerometer, or some sort of piezoelectric velocity sensor [usually one for every axis of movement, X, Y, and Z which correspond to a yaw, roll, or pitch motion]. These sensors are micro electromechanical devices that measure movement and are used to counteract motion blur associated with camera shake. When the lens moves, the movement is sensed by the accelerometer(s), or velocity sensor(s). A CPU within the lens calculates a direction and velocity by way of a mathematical calculation that averages the signal received by however many sensors are detecting movement, that is what is meant by orthogonal. It then applies a digital signal to a D/A converter that will apply a voltage to the electromagnets by way of a variable current drive circuit, at a specific polarity, in order to move the lens element proportional to the movement of the lens and relative to the optical center of the lens, varying the angle at which the light strikes the sensor or film of the camera. Blur is a result of light striking the image sensor at different directions instead of in a straight line. VR ensures that the line, or light remains straight, rendering a clear and focused image. Other types of image stabilization exist in the body of the camera as opposed to the lens and use the same principles to move the image sensor of the camera.
2007-12-13 09:47:20 · answer #1 · answered by Joe Schmo Photo 6 · 4⤊ 0⤋
VR reduces the effects of camera shake. Which is you moving while taking a picture. It does nothing to stop your subject from moving. VR is not really necessary on shorter lenses like the 18-55mm. Where it is a big benefit is on longer telephoto lenses. These are much harder to hold still and require faster shutter speeds to avoid blurry shots from camera shake. As a general rule to hand hold you should have a shutter speed that matches you focal length. So for a 250mm lens you should use a shutter speed of 1/250th of a second to avoid camera shake. VR will allow you to use a shutter speed of 1 to 2 stops slower than would otherwise be recommended. Meaning for a 250mm lens you can get away with 1/125th of a second.
2016-03-15 23:12:53 · answer #2 · answered by ? 4 · 0⤊ 0⤋
two different methods exist. One requires the lens to move and allow compensation of any vibrations. The other moves the actual sensor to compensate.
Some manufacturers bend the truth and claim vibration reduction when in fact their is none beyond forcing the camera to use a faster ISO and therefore a faster shutter speed (think Casio).
2007-12-13 08:32:19 · answer #3 · answered by IG64 5 · 0⤊ 1⤋
I wish I knew. Read that Canon's IS works by moving a few elements the opposite way the camera (lens) moves.
Here is Canon 100 - 400 mm f 4.5-5.6 L IS at 400 mm at f 5.7 at ISO 3,200. Taken indoor in a school church. Canon 5D. Hand held. Shutter speed 1/125.
It was a bit grainy, so I touched it up with Kodak GEM. Otherwise, it was sharp.
http://i30.photobucket.com/albums/c317/wtin/88f39eeb.jpg
2007-12-13 08:31:26 · answer #4 · answered by Pooky™ 7 · 0⤊ 1⤋
VR will reduce blur from camera shake, but it can do nothing for a moving object.
2007-12-13 08:38:05 · answer #5 · answered by Mere Mortal 7 · 0⤊ 1⤋
I read someplace (sorry I don't have a link, don't even recall if it was hard copy or on line) that the canons use tiny gyro servos on an element group that react inversely to the movement detected. I'll see if I can find the article again.
2007-12-13 08:41:44 · answer #6 · answered by Dawg 5 · 2⤊ 1⤋
It is done by gyros, the same thing that keeps a rocket from wobbling. gyros can be put into the lens or into the camera body. Mine digital has both.
2007-12-14 01:05:05 · answer #7 · answered by Polyhistor 7 · 0⤊ 0⤋
Great answer, MoJo. For a slightly less technical explanation, try Ken Rockwell.
http://www.kenrockwell.com/tech/image-stabilization.htm
2007-12-13 15:42:06 · answer #8 · answered by Picture Taker 7 · 1⤊ 0⤋
Take a marble and put it is a glass. Make the glass tremble and see how relatively stable the marble is.
That is how the system works too. The lens is mounted so it physically compensates for the movement.
2007-12-13 08:23:09 · answer #9 · answered by Puppy Zwolle 7 · 0⤊ 4⤋
The lens reaches out, grabs the photographer, and shakes all the money out of his wallet.
2007-12-13 18:08:27 · answer #10 · answered by V2K1 6 · 1⤊ 1⤋