# Image Stabilization Question



## KuklaPup (Jan 5, 2013)

I have been searching through the Web to find an answer to this question, but to no avail.  Maybe someone can help me.  I have a Canon system where IS is in the lens, so it's easy to see when it's working.  But, in the Olympus mirrorless IRC system with in-body image-stabilization, how does one know if IS is working?  More specifically, if I hold the shutter button half-way down for a more than a couple seconds to get proper focus, exposure and composition, does the IBIS turn off or does it stay on?  Any insights would be most appreciated.


----------



## KmH (Jan 5, 2013)

Not being able to see that in-the-body IS (mechanical stabilization, or sensor-shift stabilization) is working is one of the major disadvantages of in-the-body IS.
Stabilzation in the lens is known as optical stabilization.



> Image stabilization - Wikipedia, the free encyclopedia
> One of the primary disadvantages of moving the image sensor itself is that the image projected to the viewfinder is not stabilized. However, this is not an issue on cameras that use an electronic viewfinder (EVF), since the image projected on that viewfinder is taken from the image sensor itself. Similarly, the image projected to a phase-detection autofocus system, if used, is not stabilized.
> 
> In-body image stabilization requires the lens to have a larger output image circle because the sensor is moved during exposure and thus uses a larger part of the image. Compared to lens movements in optical image stabilization systems the sensor movements are quite large, so the effectiveness is limited by the maximum range of sensor movement, where a typical modern optically stabilized lens has greater freedom. The required sensor movement (both speed and range) increase with the focal length of the lens being used, making sensor-shift technology less suited for very long telephoto lenses, especially when using slower shutter speeds because the available motion range of the sensor quickly becomes insufficient to cope with the increasing image displacement..


----------



## dxqcanada (Jan 5, 2013)

I can tell you with my Sony SLT-A55 (it has an EVF) it does not activate the stabilizer while viewing ... it appears to activate only when the still image is taken (or while video is recording).

Not sure if that is the same with the Olympus or the Sony NEX.


----------



## usayit (Jan 14, 2013)

IBIS in most Olympus models occurs at the time of exposure.  In other words, the sensor is stabilized just moments before the image is recorded.   It will not stabilize the image during composing.  This is true for many other implementations (Pentax and Sony too) of IBIS.   You just have to be confident that it is working by seeing the recorded images.  

Specifically for the Olympus OMD E-M5, there is an option to turn on IBIS while the shutter button is pressed half way.  This WILL stabilize the image while composing (just as you experienced with Canon IS).   I turn on this option when shooting at longer focal lengths to help stabilize handheld during composition (so that handshake doesn't make me dizzy lol).  It does consumer more battery though.


----------

