ggab Loc: ?

+1

imagemeister Loc: mid east Florida

Yes, because of the increased magnification needed for viewing/printing........

Also, the more MP ( finer pixel pitch) the more shutter speed you need to keep from revealing blur .....

Bill_de Loc: US

Thanks Larry

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crazydaddio Loc: Toronto Ontario Canada

VR/IS is awesome at any focal length. The only time it has a negative effect is at "initiation" of IS you may get an instantaneous "jump" of the image in the viewfinder....after that it does have the effect of smoothing out the tracking. The SS will freeze the wingbeats of the bird and the IS is probably not going to do much for that...

...IS is best experienced for stationary objects at long focal lengths when you can lower the SS in low light to get good exposure and sharpness.

Apaflo Loc: Anchorage, Alaska

It does indeed stabilize the viewfinder image, but potentially at the expense of sharpness of the captured image if the shutter speed is too high. The technical basis for that is extremely well understood sampling theory, but it is not a common subject known to photographers.

amfoto1 Loc: San Jose, Calif. USA

No, you will not get better images without it... More likely the opposite. ESPECIALLY when using such a super long focal length handheld.... and ESPECIALLY if shooting from a moving vehicle or boat or even a non-moving vehicle with a motor idling and causing vibrations or a boat gently rocking with wave action.



And those folks would be incorrect. You cannot expect a particular shutter speed to be adequate in all situations... there are way too many variables.

The general rule of thumb is that with 35mm film cameras and full frame digital, most people can hand hold a steady shot at a shutter speed the reciprocal of their lens focal length.

So, at 150mm setting, you'd need to use a MINIMUM of 1/150 shutter speed. And at 600mm setting, you'd need 1/600.

HOWEVER, this is only a general guide line. Some people can handhold a little bit slower shutter speeds, while others need to use a little faster.

AND, that guideline is for full frame/film cameras.... using lenses on a crop sensor camera magnifies lens focal length AND it's sensitivity to camera shake. On an APS-C format camera, your lens would "act like" 225-900mm on full frame, so you'd need at least 1/225 at one extreme and 1/900 shutter speed at the other. The same lens on a so-called "Four Thirds" camera would act like 300-1200mm on full frame.... so you'd need between 1/300 and 1/1200 shutter speeds, depending upon the zoom setting.

In general, I'd recommend leaving OS enabled.... especially if hand holding the lens, but also on a monopod, or even on a tripod if using it "loosely" such as with a gimbal head or panning action, or if the tripod/monopod is sitting on a less than perfectly stable surface. For that matter, with really long focal lengths like 600mm, even a breeze or the camera's mirror actions can make for enough movement to cause "shake blur".

OS should give you two to four stops worth of "assistance".... allowing you to use the lens at slower shutter speeds than you could normally hand hold steady. For example, if you needed to use 1/1000 without OS, you should be able to handhold between 1/250, 1/125 or even 1/60 with it and get a reasonably high percentage of sharp shots.

But, you also have to keep in mind that stabilization can't do anything to help freeze the subject's movement. You can still get blur effects in your images if the shutter speed is too slow to stop that movement.

I don't use any Sigma OS lenses personally, so you should look to them for info about their stabilization system's effectiveness and if there are situations where it should be turned off.

I've been using a variety of Canon IS lenses for fifteen years and almost never turn their stabilization off. But different brands each have their own patented systems, so there are likely some differences between them. For example, a lot of Nikon VR lens users feel it slows autofocus slightly and sometimes opt to turn it off for that reason. I feel the opposite is true with Canon IS.... that it helps AF perform faster and better. But neither of these should be interpreted as guides for Sigma OS, Tamron VC or any other form of stabilization. While they all serve the same purpose, there are bound to be some differences between them.