The Low Light Photography Field Guide: The essential guide to getting perfect images in challenging light
Amazon Exclusive: An Excerpt fromLow Light Photography Field GuideHandheld or Locked DownLow light photography is one area in which process dominates. By this I mean that all the various limits and difficulties that we looked at in the first chapter need to be thought about before you start shooting. In practical terms, low light shooting is about pushing technical and mechanical limits as far as you can, and this in turn means that there are two competing ways of approaching it. In one the idea is to do everything necessary to retain the freedom of using a camera in much the same way as you would under normal light. The alternative is to abandon freedom in favor of a full choice of technical settings--sharp, clean images without noise, and at any aperture setting, and with no limit to the exposure time (except, of course, for short exposures).It is not easy to switch from one to the other mid-shoot, so it is normal to decide at the start which route you are going to take for any one session. There are good arguments for both handheld and for using a tripod, and which to choose depends on the subject, your preferred style, the results you are looking for and the quality you absolutely need. The last factor is too often ignored, as we'll come to in a moment, and can sometimes make the others redundant.The key factor for most photographers is the optimum shutter speed for subject movement. If the subject is active, for instance people in motion, a tripod is no help in freezing the movement. Some kinds of movement may well be acceptable, or even desirable, such as the streaked trails of vehicle lights on a highway, but if you need sharp capture, the threshold shutter speed for this determines everything. This in turn is affected by the relative movement in the image frame (see pages 110–113), so a walking figure naturally calls for a faster shutter speed if it fills the frame than if it takes up just a small part of the picture. But basically, the rule is, if you are photographing people, then shoot handheld.The obvious advantages are freedom and mobility, and the chance to shoot unobserved, without drawing attention to the camera as is inevitable with a tripod. You can strip down the amount of equipment drastically; one camera, one or two lenses, maybe a flash unit if the camera does not have one built in, and very little else. Gone are the days of two camera bodies, each for a different film (such as high-speed color, with high-speed black and white to be pushed to the maximum if necessary). Digitally, everything can be dialed up from the menu.The disadvantages are in camera handling and image quality. As handheld shooting in these conditions almost never enjoys the luxury of fast shutter speeds, holding the camera (and yourself) still is always an issue, and may often--as we'll see a few pages further on--call for over-shooting to lessen the risk of frames lost to camera shake. A fast lens, with a maximum aperture wider then ƒ/2, is a distinct advantage, though costly. Image quality centers on noise, because the key strategy is setting the appropriate ISO. High sensitivity means high noise levels, and while there are ways of dealing with this it reduces quality. This completely depends on how the pictures are going to be used, in particular the size. It is very important to become familiar with just how bad different noise levels look when reproduced at particular scales. The positive side of this is that if you are going to use the picture small, the noise may be invisible, thus giving handheld almost no disadvantages at all.