Understanding aperture

A little mini-series and a little challenge for me to try and condense the interplay of the key aspects of control for photography into a few short sketches (I thought about doing this much earlier, but kept kicking it down the line). Please let me know in the following ones if it helped. Though the only way really, is to get out there, play with the settings, take some pictures and learn.

One of the biggest benefits of digital photography has been the narrowing of the feedback loop between taking a photo and seeing the result. Imagine taking some long exposure night sky shots on the perfect evening after many days hiking only to find, a week or so later, that your aperture, shutter speed, ISO combo was all out of whack. But what did you do wrong? And would you remember how to correct it next time you were up there. Now you can take, test, edit, test, learn. Any time the feedback cycle narrows between doing and learning expect big changes.