All three principle of exposure, aperture, shutter speed and ISO all work hand in hand to get you a well lighted image. Aperture is quantified with fstops. a low fstop like 3,5 means that the aperture is alot wider open, in turn letting in more light. If the picture taken with that fstop was to bright than you might change it to f16 and get a darker image. Aperture also controls depth of field, which effects how much of a photo is sharp and how much of it is blurry. If you wanted to take a picture of a person you would want a wide aperture(low fstop) and for a large landscape picture you would want a small aperture(high fstop).

    shutter speed affects exposure as well as motion blur. when the shutter speed is at 1/2o of a second the sensor is exposed to light for 1/20 a second producing a blurry image if the subject is moving as well as a brighter image. if the shutter speed is set 1/2000 for example the image will be dark but a very fast moving object will seem to be frozen in time. This makes sense be cause the sensor was only exposed to the image of the object for a fraction of a second so the object only moved a very small space in that amount of time.

     Higher ISO creates a brighter picture and lower ISO creates a darker picture the catch being that a high ISO like 1600 creates lots of noise which makes the photo look very grainy. 

       

     

     

​

​

​