What is exposure, in photography?

  • Thread starter Thread starter trigger349
  • Start date Start date
T

trigger349

Guest
Someone told me, it's like when you want to take a shot of the night sky and you want the all the stars to be seen in the image. so you put it on the tripod and wait for several minutes then take the shot.

is it that?
 
Digital photography opens the possibility of great nighttime pictures.
Set your camera's sensitivity at 800 ASA and 1/30
of speed and the diafragm at 1.4 objecting the sky by full or new moon, and
during you expose, move a step to eastward.
You'll get no streaks of the stars.
 
Exposed just means it was taken and is now a photo. Maybe you are thinking of over-exposed. That's when it has a it has a lighter image and looks distorted.
 
All photography is based on a reaction of a receptor (a film or digitalized sensors) to the presence of light.

Exposure is simply the amount of light you let come in to the receptors.

There are several ways to control exposure, and one can also have some play by using receptors that have different levels of sensitivity (different film speeds).

Shutter speed is the principal control. The amount of time that the camera is open to the light is what most people consider exposure. Thus, in your example, a long exposure time is desired because the amount of light coming in per unit time is very low.

F-stop (aperture control) is another way to control exposure. If the iris (the opening in the camera) is opened wide, the amount of light coming in per unit time will be a lot higher than if it is closed to a pinpoint.

One can get some interesting effects by playing with shutter speed, aperture, lens filters, and differing film speeds. It is this interplay of the various things that makes photography interesting and fun.
 
Back
Top