[lensego]

Hi Guys
It might be a silly question
What is going to happen if you use an image stabilized lens with a stabilized body ( K7)?
Am I gaining the extra stops what my lens is giving ? I.e. Tamron 18-270mm with
Vibration Compensation (VC) optical image stabilisation (up to 4 stops)
regards zoltan

[elho_cid]

no, the two system will not cooperate, resulting in heavily blurred image. one needs to be turned off

[Entropy]

Hi Guys
It might be a silly question
What is going to happen if you use an image stabilized lens with a stabilized body ( K7)?
Am I gaining the extra stops what my lens is giving ? I.e. Tamron 18-270mm with
Vibration Compensation (VC) optical image stabilisation (up to 4 stops)
regards zoltan

No, since Pentax SR is not designed to work in conjunction with an optically stabilized lens and is not aware of the optical stabilization in the lens, having SR and in-lens IS enabled at the same time will make things work. That's why Sigma OS/Tamron VC lenses say to disable SR on Pentax bodies when OS/VC is enabled on the lens.

There's a lot of debate as to whether lens-based IS or body-based IS is better, at long focal lengths it seems like lens-based IS usually wins, and shorter focal lengths benefit better from body-based IS.

One definate advantage to lens-based IS is that the viewfinder view is stabilized and the AF system sees a more stable target. I definately see major improvements in AF performance at the long end of my Sigma 18-250 HSM OS when the lens stabilization is turned on.

[SpecialK]

I have a Sigma 150-500 with "OS" which works fine at stabilizing the image. However, you can not use the OS and the SR at the same time. Further, Sigma mentions that you need to turn off OS when changing the lens to avoid damage (which doesn't sound good). I leave OS off and use SR for that reason and two others.

If I have OS on and SR off, then the exif data list I produce by Photo Browser will indicate the image is not stabilized (a minor point, but it would bug me, same as "no flash" when I use a hand-held flash during a long exposure...)

Most of all, I like to see the image wobble so I can determine how steady I am before squeezing the shutter. If the image is stabilized in the lens, you don't really have a good idea of how much you are moving.

[Entropy]

OS off when changing lenses - I make a point of turning the whole camera off when changing lenses, so not a problem for me.

Determining how stable you are - OS is only operational while the AF system is powered. So it doesn't stabilize until you half-press the shutter. It's neat to see the image stabilize as soon as you halfpress.

[alohadave]

Determining how stable you are - OS is only operational while the AF system is powered. So it doesn't stabilize until you half-press the shutter. It's neat to see the image stabilize as soon as you halfpress.

SR works the same way on shutter half press. It's not on all the time.

[Ratmagiclady]

Or, as the Dungeons and Dragons crowd would say, "The bonuses do not stack."

[lensego]

Thanks guys. That is what i thought,but thanks clarifying it.So is there a modern so called travel lens 18-200 mm, without IS or OS, or all them has is now except Pentax? Because you have to pay for the IS.

[JayR]

SR works the same way on shutter half press. It's not on all the time.

How obvious is it though?

I put my FA100-300 @ 300mm and tried to see whether having it off, on or half pressing the shutter would be visible through the view finder - i couldnt see anything (and yes, the 'green hand' was activated)

Ive heard the 'clunk' noise when tipping the camera to its side when its off, or heard various whirrings when in live view & video modes, but no such noise when shooting.

[Entropy]

SR works the same way on shutter half press. It's not on all the time.

Yeah, but it doesn't stabilize the viewfinder anyway, so whether it is on all the time or not doesn't really matter as far as the "am I stable without IS or not?" issue raised above.

As to paying the premium - Sigma seems to be charging a MAJOR premium for OS in some lenses (BigmOS, 70-200 OS), but almost no premium at all for others. (Sigma 18-250 HSM OS was not much more expensive than I remember the screwdrive nonstabilized Tamron 18-250 to be.)

I have a Sigma 18-250 HSM OS, it's a great lens. Seems sharper than my 17-70 in most situations in fact (although this and a few other facts are leading me to believe that I may have a defective Sigma 17-70.)