Low light Photography
Photography in low light conditions is similar to photography under a normal light, but it has some peculiarities which one should consider.
A low lit situation is a situation when a shutter speed is faster than 1 divided into the foal length of a lens. For example if a focal length is 30 mm, a shutter speed should be set at 1/30 sec.
We know that if we use a long shutter speed, the quality of the final image may be affected by camera shake. It is an often case, especially when the photographer uses a long focus zoom lens. We suggest you a few solutions to help manage a situation.
Use a tripod or monopod. It will allow you to shoot at any shutter speed and avoid blur from camera shake. But you should pay attention at a tripod construction, especially at its head. Often a head of a tripod is made completely of plastic. Such a tripod can not be of much use, as it will shake with a camera. It also should be mentioned that using a tripod is a good idea even under a normal light, if you want to get crispy and sharp images. One more thing that will allow you to avoid camera vibration is using a remote control or a self timer.
Use a high-aperture optics. It will allow you to shoot with a faster shutter speed. For example, if you use a lens with an aperture 1:14, you can decrease a shutter speed by 3 stops relative to a lens with an aperture 1:4. But such practice has one side effect – you will get a narrower DOF, which is defined only by focus focal length of a lens and f-stops. The best results will be achieved if one remember about a standardized 2:1 scale, which was adopted for shutter speed so that opening one aperture stop and reducing the shutter speed by one step resulted in the identical exposure.
Actually when you shoot in low light conditions, it is recommended using exposure bracketing. A camera takes 3 pictures – one at +x, one at 0, and one at –x exposure. It allows you to determine the best exposure level for your conditions based on your evaluation of 3 pictures.
Using a Flash. In low light conditions most photographers prefer to use a flash, which may cause a number of side-effects. If you use a built-in flash, which is turned to the object, you may get flat images with red eyes. If you direct a flash to the ceiling, it may cause shadows in the area of eyes and nose of the face of your subject. With a flash on the side, you will end up with an image with deep shadows.
You can use two flashes to get rid of deep shadows. In this case you should remember that the ratio of light intensity from flashes should stand at 2:1 (light shadows) or at 3;1 (deeper shadows).
TTL cameras use a Through-the-lens (TTL) metering, which is a photographic technique in which measurements of light levels are made through the lens of a camera. Most TTL cameras control the amount of light emitted from the flash by measuring the light falling back into the flash sensor — through the camera’s lens.
In TTL, flash metering occurs after the shutter has been opened — the sensors record the amount of flash-created light returning to the camera through the lens and automatically shut off (”quench”) the flash when an appropriate amount of light has been produced.
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March 19th, 2007 at 10:24 am
Thanks for the article. I just came across this site after writing 14 tips for low light photography. I think that the auto exposure bracketing and using a tripod are two of the most helpful suggestions. I use continuous shooting mode (burst) with auto aperture mode if the camera is not on a tripod. The two articles on the subject can be found here: http://www.imagingbuffet.com
All the best,
Andrew Darlow
Editor
The Imaging Buffet