Night

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[edit] Night and Time Lapse Photography

Night shots are a ubiquitous aspect of photography, but how to capture images in very low light levels often escapes the amateur. However, once the principles involved are understood it is easy to produce professional looking shots. Most cameras including those which are not designed for professionals often include manual controls, and even better, a night shot mode.

An example of a night shot with a shutter speed of ~1.3 seconds

[edit] How are night shots possible?

There are two aspects in every camera both analog and digital that dictate how much light is captured, and therefore how light or dark the photo will be, and whether motion is captured or not. These two factors are:

• Shutter speed
• Aperture

Shutter Speed: The Shutter speed is basically a description, usually in fractions of a second, of how long the camera "opens its eye" to the scene you are trying to capture. These speeds can be as fast as 1/1000 second, to capture fast moving objects, with abundant light (cars or sports in motion in daylight), or as slow as 15 minutes or more, which is common when taking photos of stars and their apparent motion across the night sky. The longer the shutter is "open", more light is let in over time, while motion is also captured. The converse is also true: the less time the shutter remains open, the less light is allowed to enter the camera, but this also minimizes motion captured in the image.

Aperture: Simply said, aperture describes "how wide the camera opens its eye". The standard measurement unit for aperture is known as "F stops" which comes from the beginnings of photography when the interchangeable lenses were so marked. The usual range for common photos ranges from approximately F2.5 (relatively small) to F8 (fairly large) The aperture can be opened wide, or narrow, depending on what you are attempting to capture with the camera. Aperture is often a secondary aspect considered after shutter speed, but it is important nonetheless. If you want a lighter photo with less motion or blurriness, a wide aperture with a faster shutter speed will theoretically allow more light in in the same amount of time due to the larger opening, but will also be sharper, because the objects (or the camera in most cases) have less time to move while the shutter is open. This is much like how the human eye opens or closes the pupil to allow more or less light in, to compensate for lighter or darker situations. Be aware though, that changing the aperture also has a significant impact on the focus of the resulting image. A larger aperture for the most part will leave the area in front and behind the subject out of focus, while a smaller aperture will leave things both far and near in focus. This is also referred to as "depth of field".

[edit] Methodology

First, you must take into account what exactly you are taking a photo of, and what you want the resulting image to be. Do you want to see the subject exactly as is appears at night or low light conditions, show motion, or enhance the natural lighting? Determining how to shoot these different situations can usually be done by first answering a few simple questions:

• Is the subject either producing its own light or reflecting light?
• Is the subject already in motion? (and if so, do I want to capture the motion or not?)
• Is the subject going to move out of the frame?
• Do I have a tripod or other method to enhance stability?

After addressing these questions, it becomes less a matter of guesswork and more a matter of setting the camera according to the ambient conditions. If the object is producing its own light, or has been illuminated but an outside light source, depending on its brightness, a faster shutter speed is probably more appropriate. The aperture setting then can be set to have more or less of the frame be 'in focus' depending on your desires for the resulting image. Using a speed that is too slow can allow too much light in, and results in a completely white image. Conversely, if the subject is not illuminated or giving off light, (stars and planets are an exception) then a much slower shutter speed is desirable, and can extend into minutes if the subject is very faint. Beware of ambient light, as it can become overpowering if the shutter is left open too long.

A night shot of an illuminated object.

Taking photos of subjects in motion at night can be done in two ways. For example, the picture of the fountain was taken with a very slow shutter speed of ~1.3 seconds with a rather closed aperture. Because the water is always moving, the result is that the water begins to look more solid and continuous looking, rather than appearing as a series of blobs of falling water, which is how it would appear in nature. Due to the small aperture, most of the frame appears to be 'in focus'. It is important to note that when shutter speeds approach and exceed 1/10 second, a tripod or other tool to steady the camera is required. At this speed, human hands (and also camera shake reducing features) often fall short of the needed stability. If there is a suitable immovable object, such as a wall or bench, consider using this in place of a tripod. If the camera can 'see' the subject without you there to hold it in place, see if your camera is equipped with a timer. Using the timer will allow you to place the camera, and allow the camera to hopefully steady itself before the shutter opens.

A night shot of both stationary and moving subjects.

Non-stationary subjects at night can be a little more complicated, and the use of a light meter would be useful. Otherwise, trial and error is an acceptable method to determine the suitable shutter speed as long as you are using a digital camera. Analog film cameras don't enjoy this advantage and this would be a waste of film. Luckily most analog cameras typically display a light reading within the viewfinder when the trigger is depressed half way.

--dcfroburg 13:10, 4 February 2008 (CST)