The IS limits camera shake in an image, but if your shutter speeds are dropping much below 1/30th, any subject movement will still be picked up. The IS helps, but most shots indoors at f5.6 without extra light will be marginal, even f4 will not produce great shots in most indoor situations (assuming you don't have a camera that can give you at least a few more clean stops on the ISO past 800 (mainly Nikons right now but a few Canons are respectable)).
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Canon walk-around lens choices - your input required...
- Thread starter VirtualRain
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The IS limits camera shake in an image, but if your shutter speeds are dropping much below 1/30th, any subject movement will still be picked up. The IS helps, but most shots indoors at f5.6 without extra light will be marginal, even f4 will not produce great shots in most indoor situations (assuming you don't have a camera that can give you at least a few more clean stops on the ISO past 800 (mainly Nikons right now but a few Canons are respectable)).
IS works by compensating camera shake, one of the limits of shooting with a slow shutter. The general rule of thumb is that without a stabilized lens you shouldn't shoot any slower than the reciprocal of the focal length to the nearest 1/3 stop. Meaning if you have a 200mm lens, to avoid camera shake you shouldn't shoot any slower than 1/200th of a second. Current generation IS on that same lens would in theory allow you to get a sharp photo at 1/13th of a second. The problem when you get to a shutter speed that slow, is that camera shake is no longer the only factor in getting a sharp photo, now subjects can move significantly enough to make them blur in that amount of time.
On an even shorter lens where that becomes an even bigger issue because 4-stops down from 1/20th is 1.3 seconds. Think about how much someone moves while just standing still over that period of time.
In practice I've found that IS gives about a 1-2 stop advantage on the longer focal length lenses and becomes increasingly less useful the shorter the focal length is.
To the OP: this is worth understanding, so if you don't get it please read it again as many times as it takes to fully grasp the concept.
Iow, you usually want the shutter speed as fast as it takes to stop motion of the subject, which means higher ISO or larger aperture. IS is only for reducing/eliminating camera shake. And if you have tripod or really steady hands, IS has zero effect.
Yeah, I got it. I've been using IS enabled camera's (my Panasonic/Lumix) for several years.
To recap... IS offers more flexibility in terms of being able to hand-hold the camera vs. using a tripod... but of course, it doesn't affect the shutter speed which is required to properly capture action or subjects which are not perfectly still.
Where I see IS being an advantage, besides the obvious telephoto end of things, is in taking scenic shots in disappearing light or on a dark and dreary day where a longer shutter speed would be required but you don't have a tripod handy, AND indoors where you may be shooting in a museum or other venue where flash is not allowed and again, a tripod is not handy. Unless I'm wrong, this goes against FX120's assertion that IS is useless in low light and indoors.
Yeah, I got it. I've been using IS enabled camera's (my Panasonic/Lumix) for several years.
To recap... IS offers more flexibility in terms of being able to hand-hold the camera vs. using a tripod... but of course, it doesn't affect the shutter speed which is required to properly capture action or subjects which are not perfectly still.
Where I see IS being an advantage, besides the obvious telephoto end of things, is in taking scenic shots in disappearing light or on a dark and dreary day where a longer shutter speed would be required but you don't have a tripod handy, AND indoors where you may be shooting in a museum or other venue where flash is not allowed and again, a tripod is not handy. Unless I'm wrong, this goes against FX120's assertion that IS is useless in low light and indoors.
IS is useless when the major source of blur is subject motion. If I'm photographing someone speaking at a podium, I know that I can get a reasonably sharp image at 1/50, and perhaps 1/30 if I'm lucky. So if I'm at 200mm effective, which would normally require 1/200, with IS I can move down to 1/50 (2 stops) and still get sharp images, because camera movement is still the limiting factor. Beyond 1/50 or so, subject motion becomes limiting and IS doesn't help.
So IS can help even with shots of moving objects, as long as the predominant cause of blur is still camera movement.