Tuesday, May 24, 2011
The Promise Of Stabilization
Between image-stabilized lenses, in-camera stabilization and high-ISO technology, the game has changed for photographers seeking the freedom to shoot handheld
The best IS lenses also feature special panning modes or switches for use when you're tracking a moving target. These produce superior results by ignoring side-to-side motion and only reducing shake along the vertical axis. Other lenses can detect when the camera is set on a tripod automatically and turn off the IS so you can save battery life. Finally, when it comes to shooting video, both IS systems can help reduce shake to some extent, but IS lenses are generally quieter and further away from the built-in camera microphone. At least one zoom lens from Panasonic has a completely silent IS engine.
High ISO Changes The Rules For Working Without A Tripod
You may have noticed that neither the light-gathering capacity of the lens (determined by its maximum aperture) or the ISO setting of the camera is factored into the Reciprocal Shutter Speed Rule. These two features are only indirectly related to the amount of blur you can expect when shooting at low shutter speeds and, instead, determine whether you need to use a low shutter speed at all to produce a proper exposure. A brighter lens and higher ISO settings both let you use a faster shutter speed in a given low-light situation. Unfortunately, large-aperture telephoto lenses are expensive and rarely give you more than a two-stop advantage over a cheaper lens. But that two-stop advantage (for example, ƒ/2.8 vs. ƒ/5.6) is worth the price if you're an avid low-light shooter or if you want the added depth-of-field separation provided by wider apertures.
Increasing the camera's ISO to improve low-light performance can give you several more stops of improvement compared to a brighter lens or image stabilization. Many point-and-shoots do this automatically when their "electronic" image-stabilization feature is turned on. However, the price you pay for increasing ISO is a decrease in image quality. How much it decreases depends on the camera and its sensor. Most DSLRs let you dial up ISO to gain a three- to five-stop improvement in light sensitivity (compared to the camera's base ISO) before image quality becomes unacceptable. For example, assuming you own a fairly modern APS-C DSLR with a base ISO of 100, you may find images shot at ISOs from 800 (three stops) to 3200 (five stops) to be acceptable.
Page 4 of 5
Get 11 Issues of Outdoor Photographer for only $14.97!
That's 77% off the cover price!