Camera Shake and Image Stabilization
(Vibration Reduction)
By: Neil Galloway
When you are first buying camera equipment you see a
lot of lenses that have the IS or VR
designations on them. This is Image Stabilization
or Vibration Reduction. They mean the same
thing except Canon uses the first term and Nikon
uses the second. These are mechanisms built into the
camera lens to prevent "camera shake". I will
discuss how to get rid of camera shake and why I
purchased a VR lens for myself.
What
is Camera Shake?
When you are holding your camera in your hands and
looking through the view finder to take your photo,
your body is making slight movements. This is a
natural thing as your body is always correcting
itself and your muscles move to help maintain your
balance. However, it causes slight movements in your
camera. When your camera is zoomed in on a subject
that is a reasonable distance away, these slight
movements become more noticeable.
For example. If your hand slightly shakes and turns
your camera 1 degree off its line of direction and
your subject is 15 feet away, this would correspond
to 3.1 inches being added in the direction your
camera turned. Now say that the movement of your
hand happened when you took your picture and while
the shutter was open. This would blur the image on
film or on your digital image.
How Do I Prevent My Pictures From Blurring?
There are 3 ways to prevent this.
1. Make sure you have a shutter speed
fast enough so that your hand movements don't affect
the picture.
2. Use a tripod.
3. Have a lens with vibration reduction
or image stabilization.
Each of these methods have their pros and cons.
1. Have a Fast Enough Shutter Speed
Ideally, you would want this situation every time.
The rule of thumb is that you need a shutter speed
of 1 over the focal length your lens is set at. So
if you are zoomed all the way in with your 300mm
lens, you would want 1/300 second shutter speed or
better (so 1/320 on the standard camera). This will
usually guarantee (for the average user) the shutter
won't be open long enough to make your hand
movements noticeable on the final image If you have
steady hands you will be able to get away with a
slower speed. The catch here is will you have enough
light to expose your picture. If it is the middle of
a bright day you are fine. If it is darker you might
have to use a more sensitive film, but this will
cause your picture to be grainier.
Note: When you see expensive lenses with the same
zoom capability as a cheaper lens, look at the
maximum aperture for this lens. Chances are it will
be a lot larger than the cheaper one. F/2.8 is a
common one. The lower the number, the larger the
aperture can go. This means a lot more light will
get let in when you take the picture, so it will be
able to have higher shutter speeds.
2.
Use a Tri-pod
This will always work. Now you can have the shutter
open as long as your want and the image won't have
any blurring (this is assuming your subject isn't
moving or is moving slowly). Tripods are cumbersome
and annoying however. And they definitely don't work
in a lot of circumstances, especially traveling.
3. Use a Lens With Image Stabilization or
Vibration Reduction
This is "meet in the middle" approach as you still
need a decent shutter speed, but you won't need a
tripod and its cheaper than a fast lens. Inside the
camera there is a mechanism to adjust the glass
lenses slightly to compensate for the movements of
your hand. IS and VR will give you a few shutter
speed stops back. So if you can't quite get enough
light to have 1/320 sec shutter speed as in the
example above. VR will let you go down to 1/125 sec
(4 full stops in ideal situations). A lot of times,
this will give you enough light to properly expose
your image. VR and IS will make a lens cost extra,
but they are still cheaper than buying the fast
lenses I spoke of above. Fast lenses don't usually
have much zoom capability either (a limitation of
having such a large aperture).
The main article has an example of two images. One
was taken without VR turned on and the other had VR
on. This is a picture in my home taken with my Nikon
D70s with the Nikon 18-200mm VR lens.
To summarize. The cheapest solution is to buy
a tripod, the second is to buy a lens with IS or VR,
and the most expensive is to buy "fast" lenses. I am
a casual photographer and use it more for traveling
so VR has been the best option for myself. If you
find yourself with similar needs and want to
eliminate camera shake from more of your photos,
then I would definitely recommend looking at VR and
IS lenses.
For more articles on photography from this author,
please check out
www.thoughtsfrommylife.com/category-Photography.
The author maintains the site
www.thoughtsfrommylife.com.
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