View Full Version : Question regarding OS

18-07-2010, 7:25pm
G'day all

I'm doing some research into OS systems that leads to a question ...

If the OS is built-in to the body [as is Pentax & others] what is the benefit of having a zoom with OS built-in?
Surely this is merely doubling up on the same tech stuff

Regards, Phil

18-07-2010, 9:28pm
Gday Phil....I just bought a Sigma 150-500mm lens new. They have left the OS off the lens as myK20d already has it.
I believe the same applies to Sony who also have built-in OS< Dave

18-07-2010, 9:32pm
OS in the lens has a + in that you get a clearer image in the viewfinder at the cost of less battery life.
OS in the lens at long lengths has a slight performance advantage over in body SR.
Sigma are releasing OS version for :plogo:

19-07-2010, 8:42am
G'day Kym

Thanx for your reply
I have a student asking me whether to go for the Sigma 70-300mm F4-5.6 APO DG Macro - for $300 OR the "NEW" ... Sigma 70-300mm F4-5.6 DG OS - for $600

To me it seems that if the OS is in-body rather than in-lens, then there is a questionable advantage to having it twice, unless the OS in the lens is differently geared for a different centre-of-gravity

Any thoughts?
Regards, Phil

20-07-2010, 10:26pm
G'day Phil,

Not sure that these links will answer your question (in body SR + lens OS) but I have found them useful for learning about the various pros and cons of the two systems. The sigma website may also provide some useful tips. Some say there is an advantage to having it twice others the opposite, will try and find a thread in the pentax forum to this end that I read a couple of months ago!






20-07-2010, 10:48pm
G'day Phil,

looks like Sigma says no point having it twice



Sigma's own unique OS (Optical Stabilizer) technology

The lens is equipped with Sigma's own unique OS (Optical Stabilizer) function. This function uses two sensors inside the lens to detect vertical and horizontal movement of the camera and works by moving an optical image stabilizer lens group to effectively compensate for camera shake. It offers the use of shutter speeds approximately 4 stops slower. Mode 1 is ideal for general photography, and Mode 2 is effective on moving subject such as motor sports etc. For Sony and Pentax mount, the built-in OS function of this lens can be used even if the camera body is equipped with an anti-shake function. As compensation for camera shake is visible in the view finder, the photographer can easily check for accurate focus and ensure there is no subject movement.
*For Pentax and Sony mounts, it is not possible to use the AF and the built-in OS function of this lens when attaching it to film SLR cameras as well as Pentax *ist series and K100D.
*When using the OS function of a lens with a camera which incorporates a stabilizer unit, please turn the camera’s stabilizer unit off.
*For Nikon and Canon mounts, Optical Stabilizer (OS) function will not work with film SLR cameras except Nikon F6 and Canon EOS-1V.