Nikon VR and Canon IS - Please help me get this straight ...

Discussion in 'Digital Photography' started by igmolinav, Oct 28, 2011.

  1. igmolinav macrumors 65816

    Joined:
    Aug 15, 2005
    #1
    Hi,

    Some Nikon and Canon lenses have a feature that help them reduce vibration or increase stabilization while shooting with low light. These lenses are either VR or IS, depending on the brand name, Nikon or Canon.

    Anyways, suppose you are using an older camera model with max. ISO of 1600. Your minimum aperture value for the lens you are using is f/3.5 This is NOT a VR or IS lens and is getting dark. With 1/8th of a second and holding your breath, your picture turns out ok but perhaps a bit blurry.

    Now, suppose the same situation as before at right the exact time, but now with a VR or IS lens. What happens if your lens can not be opened any wider than f/3.5 ?? These companies say that there is a compensation of up to some three stops with the VR or IS. So the compensation is in speed, right? I could theoretically under this situation with the VR or IS now shoot with 1/60th of a second,
    or
    if it gets darker, I could still shoot at 1/8th. A situation that without the VR or IS would be perhaps impossible.

    Thank you very much in advance, kind regards,

    igmolinav : ) !!!

    P.S. This is a quote from the lens I have interest in:
    The innovative VR or IS system allows handheld telephoto zoom shooting even in poorly lit conditions. It minimizes image blur caused by camera shake, and offers the equivalent of shooting at a shutter speed 3 stops (8 times) faster.

    P.S. Does it also mean that ider focal lenghts like 18 mm. in DX format it does not work ??
     
  2. r.j.s Moderator emeritus

    r.j.s

    Joined:
    Mar 7, 2007
    Location:
    Texas
    #2
    It doesn't exactly work like that ...

    If you can hand-hold and get a clear shot at 1/30 sec without VR/IS, then using VR/IS, you could theoretically get a clear shot at 1/4 sec (assuming f/stop and ISO are the same).

    IS/VR allows you to shoot at slower shutter speeds and has nothing to do with focal length.
     
  3. igmolinav thread starter macrumors 65816

    Joined:
    Aug 15, 2005
    #3
    Hi,

    Thank you : ) !!! I see what you mean !!!

    Kind regards,

    igmolinav
     
  4. OreoCookie macrumors 68030

    Joined:
    Apr 14, 2001
    Location:
    Sendai, Japan
    #4
    There are several potential sources of »blur« in images, camera shake and motion blur. Camera shake is what happens when the camera moves significantly during exposure of the image. Then the exposed image is really an overlay of many, slightly shifted images which reduces the perceived sharpness of all of the image. You can reduce camera shake by choosing a faster shutter speed, improving a more steady grip, use of a tripod or by a lens with image stabilization. More on that below.

    Motion blur on the other hand happens if the subject moves during the exposure, even though the camera is fixed. Think of a race car or another fast-moving object. The only way to reduce motion blur is to select a faster shutter speed. In practice, this means you either have to get a faster lens (so you can trade a larger aperture for a faster shutter speed) or cranking up the ISO setting on your camera. Image stabilization will help you zilch here.

    Image stabilization has many names, Nikon calls it VR, Canon calls it IS, Sigma uses OS. There are two main methods: either you stabilize a particular lens or you stabilize the sensor. If you stabilize the lens, you insert movable optics in the lens which counteracts any camera motion that is detected. Other manufacturers such as Olympus stabilize the sensor rather than the lens, i. e. the sensor's position can be adapted to compensate for camera movements. Then every lens is stabilized, but Canon, Nikon et al claim it is less efficient. Again, image stabilization allows you to significantly reduce motion blur, the marketing material claims an improvement of 2-4 stops.

    While it is debatable if it is 2, 3 or 4 stops, ultimately, in most practical applications, the usefulness of image stabilization is limited by motion blur of the subject.
     
  5. igmolinav thread starter macrumors 65816

    Joined:
    Aug 15, 2005
    #5
    Hi OreoCookie,

    Thank you : ) !!! Very nice explanation !!!

    Kind regards,

    igmolinav : ) !!!
     

Share This Page