The Classical Period of music may have given its name as the popular descriptor for all of Western sophisticated instrumental composition, but its actual timeline is relatively short. All of the other delineated musical eras get at least a full century. However, the Classical Era is often cited as the latter half of the eighteenth century. At its longest, the Classical Era ran just seventy to eighty years, ending no later than 1820. Despite the Classical Era's short run, its impact on instrumental music has been enormous.
Shutter: This allows light to pass through for a determined period of time.
ISO: This measures the sensitivity of your sensor.
Aperture: Controls the amount of light reaching your camera's sensor.
It depends on which type of leaf, but I'll try to show you a simple one. I found this picture, I hope it's useful.
