Long Exposure Photography

Understanding the Concept of Exposure - Often after buying a digital camera either DSLR or point & shoot, we are fixated on the auto mode for quite a long time. Auto mode is the easiest and fastest, but does not provide creativity satisfaction.

For those who want to "pass and grade" from auto mode and want to channel the creative soul into the resulting photographs, it's good we understand the concept of exposure. Famous photographer, Bryan Peterson, has written a book called Understanding Exposure in which the concept of Exposure is explained easily.Peterson illustrates three elements that must be known to understand exposure, he names his third relationship as a Photography Triangle. Every element in this photographic triangle is related to light, how light enters and interacts with the camera.Long exposureThe three elements are:

• ISO - a measure of how sensitive the camera's sensors are to light
• Aperture - how much the lens opens when the photo is taken
• Shutter Speed ​​- the "window" range in front of the open camera sensor

The interaction of these three elements is called exposure. Changes in any of the elements will result in changes in other elements.

Parable of Exposure Triangle
Perhaps the easiest way to understand exposure is to give a parable. In this case I like the parable of the exposure triangle as well as a water tap.

• Shutter speed for me is how long we open the tap.
• Aperture is how wide we open the faucet.
• ISO is a strong boost of water from a water supply company.
• While the water flowing through the tap is the light received by the camera sensor.

Of course not a perfect parable, but at least we got the basic idea. As you can see, if exposure is the amount of water coming out of the tap, then we can change the exposure value by changing one or the combination of the three constituent elements. You change the shutter speed, meaning change how long the tap water is open. Changing Aperture means changing how big the water discharges, while changing how strong the water boosts from the source.