Do you guys use VR on or off mostly?

Started Apr 23, 2013 | Discussions thread
Robin Casady Forum Pro • Posts: 12,898
Re: Do you guys use VR on or off mostly?

Photo Pete wrote:

Midwest wrote:

Robin Casady wrote:

Midwest wrote:

Robin Casady wrote:

Read Thom's article on VR. There was no benefit to using VR at 1/3200 sec. and possibly some damage. At 1/500 and faster, VR cannot react fast enough to be of use, and if you catch it just right (or just wrong, actually), it will blur edges.

Suppose however that you're shooting at any significant tele or zoom focal length. While you are framing and composing your shot, with VR turned on, your camera's autofocus and metering are getting good solid info about your image up to and after you press the shutter release. With it off, the camera and AF are working with a jittery tele focal length the whole time and your view through the OVF is also jittering around.

It doesn't matter if the shutter speed is going to be fast enough that there won't be motion blur, wouldn't you rather have metering and autofocus that's working with a useable view instead of something shaking all round? I would.

I wouldn't want to risk image degredation unless I had proved to myself that VR was necessary for AF to function properly in the given circumstances. I usually shoot manual exposure, so that wouldn't be an issue.

That's your choice of course. I haven't ever felt I was risking image degradation while using stabilization on any hand-held shot. I only turn off my camera's stabilization when shooting from a tripod when the camera is going to be rock solid. Then, I think there is a chance of the stabilization causing a problem when there is no reason to use it.

Do the math. The sampling frequency of VR is 1000Hz, which means it can't cope with a shutter speed faster than 1/500.

Rather It can't cope with a vibration frequency higher than 500Hz. Why does that equate to a shutter speed of 1/500 sec? I doubt hand held vibrations exceed 500hz and so they would be correctly compensated for regardless of shutter speed?

From Thom:

"While this sampling frequency is of the camera motion, it is not completely uncorrelated with shutter speed. For example, the shutter curtains only travel across the sensor at speeds above 1/250, exposing only a portion of the image at a time. Another aspect of the VR system is that it "recenters" the moving element(s) just prior to the shutter opening. Simply put, there's a lot that has to be right at very short shutter speeds in order for there not to be a small visual impact, especially with long lenses."

I take that to mean there isn't enough time after centering to properly adjust for movement with 1/500 or faster shutter speed.

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Robin Casady
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts."
— Bertrand Russell

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