Thanks to member Bigdazzler for this information:
The Triangle - , ,
These three things will determine the , ie. how bright or dark, of all pictures you take with your DSLR, and how they will ultimately look.
- is the amount of time the is open whilst taking a picture. Most entry level DLSR cameras offer speeds variable between 1/4000th of a second (a very fast ) and 30 seconds ( a very long or slow , commonly referred to as a " long .") The time that the is open when you take a picture determines how much will reach your sensor. Think of your sensor as like a roll of film, the sensor records everything that the camera sees through your lense. Your chosen , along with your chosen " " and ( see below ) will in part determine how bright or dark your picture will be.
- The " " is an adjustable diaphragm, or hole if you like, inside your which can be opened and closed to different sizes. Different settings, or variable sizes of the hole are commonly referred to as "f- " and are indicated in "f numbers" on your LCD screen and/or in the viewfinder of your camera. For example, f2.8 , f3.5, f4 , f5.6 , f8 etc. The "f " or "f numbers" on your camera screen can be set at certain intervals or " " usually up until a "f number" of around f22 , and sometimes beyond.
These "f numbers" or "f " are indicative of what size the hole is set at within your .
IMPORTANT: Smaller numbers mean the " " (ie. diaphragm or hole) is opened up to a larger size, allowing more through the . Larger numbers mean a smaller " ", resulting in a lot less travelling through the and reaching the sensor.
It sounds kind of backwards , large hole small number .. and ... small hole larger number .. but you will get used to it !! Think of it in terms of as you close the or hole in the to a smaller sized hole, resulting in less being allowed to travel through the and onto the sensor, you are "stopping" ( remember f-" " ) down the .
apertures or f- can be chosen or set manually by the photographer to achieve different results in your final picture. settings not only affect the amount of entering through the but will greatly affect a creative aspect of DSLR photography called " ", or the amount of focus within an image. But thats another discussion
- is an abbreviation of " International Standards Organisation ". Not important really but there you have it anyway !!
is a measurement of how sensitive your cameras sensor is to entering through the and/or and is measured in these numbers. eg. 100 , 200 , 400 , 800 , 1600 , 3200 and sometimes 6400 on much more expensive higher end cameras. Most DSLR cameras will also have an AUTO setting.
You will notice the numbers DOUBLE at each interval , this indicates that the sensitivity of your cameras sensor DOUBLES each time the setting is increased. Increasing your means that you will need to adjust either your and/or to compensate for the increased sensitivity of your sensor.
REMEMBER: , AND ALL CORRESPOND TO AND WORK WITH EACH OTHER TO OBTAIN CORRECT : That's why we call it the Triangle , they are all as important as each other !!
Now there is a whole lot more to learn about these three critical elements but I hope this has given you a good basic definition of what the triangle consists of and how each of the three important elements does their individual jobs in creating correct for your pictures.