I use Auto ISO. I usually set my ISO for 200, set the auto for a Maximun 0f 3200 and let it go. With my D300, I have found that indoor shots at 3200 ISO produce excellent photos, with little noise.
Please look at tha following article via Digital Photography Newsletter
Advanced Mode: Taking Advantage of Auto ISO
What’s the most useful but most neglected feature of your digital camera? Doesn’t matter if it’s a digicam or a dSLR, either. Think a minute….
Oh, you read the headline.
Yes, Auto ISO is something often ignored during camera setup. And, in fact, manufacturers have taken their sweet time refining it. And then the marketing department got their hands on it and really confused everyone by calling it, on a digicam at least, digital image stabilization.
Actually, it’s just letting the camera pick the ISO for you. Except it has two modes on advanced digicams and dSLRs: a plain Auto mode and a capped, configurable Auto mode in which ISO is adjusted within a certain acceptable range that you set.
There never was an Auto ISO of any kind on a film camera because the whole roll was the same sensitivity. You bought ISO 100 or ISO 400 film, set the camera’s ISO to match (so the built-in exposure meter would take the film sensitivity into account) and shot away, worrying about aperture and shutter speed.
But on a digital camera, aperture and shutter speed are just two legs on the old exposure stool. ISO can also be adjusted for any image.
You can (and probably do) set ISO sensitivity for the situation at hand. That may be cranking it up to ISO 800 and turning off the flash, for example, to get some nice natural light shots. Or setting it to ISO 200 for a sunny picnic to minimize noise. And as long as you’re shooting in that situation, locking down the ISO lets you concentrate on aperture and shutter speed (unless you have those on Auto, too).
If you set the camera on Auto ISO, however, your camera can help minimize blur either from a shutter speed that’s too low or from a subject that’s hyperactive. It does that by monitoring the image. If it detects blur, it simply raises the ISO. And if you’re shooting a bright landscape with no motion in it, it can lower the ISO to get the most noise-free image your camera can produce. That’s how it got the “digital image stabilization” label.
On some cameras Auto ISO is a single setting, simply called Auto in the list of ISO options. But on others, there is more than one Auto option or, in the case of a dSLR, a configurable Auto.
Configurable Auto ISO lets you set the upper limit that the camera can use to set ISO. It may be a conservative ISO 400, which generally tends to exhibit very little more noise than ISO 200. You may select ISO 800, which on a digicam (but not a dSLR) usually does come at the price of more noise. Or ISO 1600, if you are more concerned about getting the shot than noise. And, yes, some cameras even let you set the upper limit of Auto ISO even higher.
But Auto ISO isn’t just about raising the ISO value. You’ll often find that it actually lowers it, providing a cleaner image than you otherwise might have gotten. We tend to set ISO as high as we need it, but we rarely bother to lower it when we can. Auto ISO does both.
And it does it in finer increments than the camera settings, sometimes with half the steps of the listed options you can set.
On a high-megapixel digicam, noise tends to become objectionable pretty low on the ISO ladder. You may find ISO 400 to be as far as you want to go. Earlier digicams didn’t even have the feature, though.
On a dSLR, though, with its larger sensor, noise doesn’t often become objectionable until you hit four digits. Setting the camera to manual control for aperture and shutter speed while letting ISO float can be the trick you need to shoot sports inside a gym or grab action on the street.
So next time you’re setting up your camera, don’t stop after picking how to handle the aperture and shutter speed. Remember to set the ISO, too — and consider using Auto ISO, either straight or capped