What You Need to Know About Lenses With Image Stabilisation

Many photographers don’t have steady hands, in fact even if you think
you have steady hands, you probably still can’t pull off decent low light photos at an exposure
of half a second, believe it or not. However, there are many lenses on
the market today that offer image stabilization. Understanding how image
stabilization works can help you use it to your advantage for more than
just getting sharper images in half second exposures.
Photo by benjamin-nagel

 How Does Image Stabilisation Work?

Essentially, when a lens includes image stabilization, the optical
elements in it are surrounded by electromagnets which makes them float.
When motion is induced the electromagnets guided by gyroscopic sensors
compensate for the motion in the opposite direction, thus effectively
removing a lot of vibration from the lens and its effects in the final
image. Image stabilization in the sensor works pretty much the same way,
just instead of the lens, the sensor is the one that compensates for
movement.
Most lenses with image stabilization boast stabilization around 4
stops. However you need to understand that the lens will help you get a 4
stops sharper image against a subject that is stationary. For subjects
in motion, the old rules still apply (faster shutter speed in order to freeze the action) or else you will get motion blur.

When to Use Image Stabilisation

Panning. Some lenses feature image stabilization
which can be turned on just for the vertical axis, which can let you
have that smooth motion blur when panning, while maintaining more of the
object in motion in focus because the lens compensates for the hand
movement that goes up and down. Not that regular panning doesn’t work as
well, but it is different since it compensates for every movement and
the motion blur looks a bit jagged in comparison. Note that this doesn’t
occur with every image stabilization system which doesn’t allow per
axis usage.

For example, here is an image where the motion blur is smooth and creamy:

Photo by danichro

And here is an example of a jagged one:

Photo by Takashi



Bear in mind that the jaggedness can occur due to flickering lights
as well. Everything that is led or similar flickers on 50 or 60 Hz,
therefore in an exposure that lasts half a second that light will
flicker 30 times, and when you pan, that flicker will show. The result
is very similar with image stabilisation, just that it occurs even on
sunlight when there is no flicker at all.
In Motion. Another scenario where you can capture
motion while using the stabilising function of the lens is when you are
in motion. For example, if you are shooting from a moving car. No road
is smooth enough to avoid any vibrations or movement for your camera in
that situation. Therefore image stabilisation can be particularly
useful, especially for sports photographers and the like, who often
follow marathons, bicycle, triathlons and so on while mounted on a car
or a pickup truck.
Low Light. When it comes to low light scenarios,
image stabilisation technology shines. When using flash for indoor
photography for example, you can sync the flash to the second curtain
and set the exposure to capture the ambient light in a scene. When you
have the stabiliser on, you can go further with the exposure and gather
more light, without having any blur created by the longer exposure,
while the flash will cover the difference to the correct exposure.

Photo by Sebastian Anthony

When Not to Use Image Stabilisation

However, if you are going to do long exposures on a tripod, it is
wise to turn off image stabilisation. As good as it is, it can be
damaging, as it can induce motion when there is none. Although this
happens rarely, and mostly with older models of stabilisers, it is not
worth the risk when you have your camera on a tripod, because image
stabilisation works from the time you press the button to focus untill a
moment or two after the exposure ends.

A Few Downsides

In the meantime, it drains the battery – not much, but still a
little. I’ve noticed that I have around 30% less shots per charge when
using stabilised lens. It varies from model to model, but it is worth
noting.
Another fact about image stabilisation, since there is physical
stabilisation in the lens, is that it stabilises the image in the
viewfinder as well. For about 10% of photographers it causes headaches
due to eyestrain when used for more than an hour!

http://www.lightstalking.com/image-stabilisation/