Low Light Digital Photography

Achieving good quality photos in low light can be accomplished in a number of ways. The traditional methods for handling low light situations still apply, such as increasing aperture, reducing shutter speed, using higher ISO or use of a flash. However with digital photography there are additional considerations.

Increasing aperture (lower F-numbers) opens the lens' internal blades that restrict light from entering the camera. By letting more light in, you can obtain a better exposure while keeping other camera settings the same. The two issues to consider when using a reduced f-number, is the reduction of depth of field and most lenses do not perform as well at their widest apertures.

Lowering shutter speed without making other adjustments can also help in getting the desired exposure. The rule of thumb is to set shutter time to no less than the focal length of your lens. So if you are using a 50mm lens, you should generally try to keep the shutter speed above 1/50 of a second. This will help prevent blurring the image due to camera shake (tripod can help).

Camera shake and the blurring of images is always a problem when using long shutter times. Using telephoto lenses makes this issue even more of a problem. Wildlife photographers, sport shooters and reporters often struggle with creating good images in less than ideal lighting.

Fortunately modern image stabilization systems are available from all major dSLR manufactures. Currently there are two methods for implementing image stabilization. The first is a system built into the camera body (Sony, Pentax and Olympus) which actually move the sensor to counter camera movement. The second type is the in-lens systems (Canon and Nikon) that move internal parts of the lens to reduce blurring of images. Which system is better is a matter of Internet e-arguments that will probably never reach a conclusion. In either case IS systems significantly reduce problems due to camera shake during shooting.

Increasing ISO increases the cameras sensitivity to light. So a higher ISO will allow you to use higher shutter speeds and/or smaller apertures in the same lighting conditions. These changes can be helpful for controlling depth of field, maintaining focus and capturing sharp non-blurred images.

In the days of film this was done by using high ISO film. In the digital era all you need to do is locate the ISO adjustment on the camera. However, just like high ISO film had problems digital high ISO settings come at the expense of digital noise.

Thankfully recent advances in camera sensors, especially with digital SLR types, allow for very high ISO setting with relatively less noise. Improvements in noise reduction software have also made extremely high ISO photography viable. Recent advanced amateur level cameras from Nikon (D300) and Sony (A700) allow for ISO setting of up to 6400 and the Nikon professional D3 dSLR is useable up to ISO 25600!

Advances in dSLRs have made flashless low light shooting much easier than it once was. High ISO performance and image stabilization systems are rapidly developing. The cameras that are available today are very good but you need to do your homework before you buy. If you are not yet invested in one systems lenses you have a lot of excellent options, but don’t sell yourself short buy picking up an out of date camera body unless you know what you are giving up by saving some money.