|
Multiple Lamp Sets
In photography, a multiple exposure is an exposure in which the sensitivity to light is reduced and then increased at least once during the total exposure time. more...
Home
Bath
Bedding
Furniture
Gardening & Plants
Home Decor
Lamps, Lighting, Ceiling...
Bathroom Lighting
Ceiling Fans
Ceiling Fixtures
Chandeliers
Children's Lighting
Desk Lamps
Exterior, Landscape Lighting
Floor Lamps
Lava Lamps, Party Lights
Lighting Accessories
Multiple Lamp Sets
Neon Signs
Night Lights
Other Lamps, Lighting
Paper Lanterns
Pendant Lighting
Picture Lights
Recessed Lighting
Sconces, Wall Lamps
String Lights
Table Lamps
Track Lighting
Under Cabinet Lighting
Patio & Grilling
Pools & Spas
Rugs & Carpets
Overview
Ordinarily cameras have a sensitivity to light that is a function of time. For example, a one second exposure is an exposure in which the camera image is equally responsive to light over the exposure time of one second. The criterion for determining that something is a double exposure is that the sensitivity goes up and then back down. The simplest example of a multiple exposure is a double exposure without flash, i.e. the camera image is responsive to light twice during the complete exposure.
Some single exposures, such as "flash and blur" use a combination of electronic flash and ambient exposure. This effect can be approximated by a Dirac delta measure (flash) and a constant finite rectangular window, in combination. For example, a sensitivity window comprising a Dirac comb combined with a rectangular pulse, is considered a multiple exposure, even though the sensitivity never goes to zero during the exposure.
Double exposure
Analog
In film and photography, double exposure is a technique in which a piece of film is exposed twice, to two different images. The resulting photographic image shows the second image superimposed over the first. The technique can be used to create ghostly images or to add people and objects to a scene that were not originally there. It is frequently used in photographic hoaxes. It also is sometimes used as an artistic visual effect, especially when filming singers or musicians.
It is considered easiest to have a manual winding camera for double exposures. On automatic winding cameras, as soon as a picture is taken the film is typically wound to the next frame. Some more advanced automatic winding cameras have the option for multiple exposures but it must be set before making each exposure. Manual winding cameras with a multiple exposure feature can be set to double-expose after making the first exposure.
Since shooting multiple exposures will expose the same frame multiple times, negative exposure compensation must first be set to avoid overexposure. For example, to expose the frame twice with correct exposure, a -1 EV compensation have to be done, and -2 EV for exposing four times. This may not be necessary when photographing a lit subject in two (or more) different positions against a perfectly dark background, as the background area will be essentially unexposed.
Medium to low light is ideal for double exposures. A tripod may not be necessary if combining different scenes in one shot. In some conditions, for example, recording the whole progress of a lunar eclipse in multiple exposures, a stable tripod is essential.
Read more at Wikipedia.org
|
|