“Abstract photography can be defined as capturing images in which the subject isn’t the most interesting element”

I think that abstract photography is sometimes used as an excuse to create unappealing or other forms of “wrong” photos. However I think that it can also be used to create new interesting types of photos and shed new light on old subjects. Creating different perspectives and new conversations.

Yet, I am also not the most familiar with abstract photography, and wonder…

Is it related to modern art?
What can be considered “abstract photography”?
Who are some notable abstract photographers?
What are some famous abstract pieces?