(Really, this is about abstraction in visual media in general — photography, painting, illustration, etc. — but I will focus more on photography).
I’m not officially schooled or trained in art theory, but my homespun definition of abstraction is very direct:
Abstraction is when the composition is more important than the subject.Me
To me, this is the perfect definition. I am very proud of it, and I believe it’s much better than conventional definitions. For example, the Tate website entry on abstract art says: “Abstract art is art that does not attempt to represent an accurate depiction of a visual reality but instead use shapes, colours, forms and gestural marks to achieve its effect.” IMHO that definition is anchoring too much in representation. What’s more important is what is the piece about: itself, or the subject?
Here’s one of my photo abstractions:
There’s nothing life-changing about this photo, but it’s still a good example of abstraction. It’s not about the plant, or the table, or the restaurant. It’s about the composition. The curvy shapes of the plant contrast with the geometric shape of the table, which contrasts with the round shape of the planter and pot. The green of the plant contrasts with the yellow of the table, but there is yellow in the plant as well, so they have a connection. Both yellow and green contrast with the blue/gray of the wall and floor. The corner of the table sort of “points” at the plant. And so on.
This drawing of bulls by Picasso is my preferred example of abstraction:
The less lines and value used, the more you just enjoy the fundamental shapes and pieces of the bull rather than thinking about the bull.
Notice that abstraction leans on ideas of minimalism — namely, the idea of less — but is separate. Jackson Pollock was an abstract expressionist, although he sure slung a lot of paint around and is not often considered a minimalist. But he did use less, in the sense of less discernible shapes.
Astute readers will note the previous Picasso example is not a photo. That’s ok, it’s still the best example.
Some photographic subjects, such as sand dunes, slot canyons and various funky angles of architecture, also support abstraction well. Macro photography of surfaces and textures has the same effect.
In short, IMHO part of being a photographer is trying out abstraction and seeing if it works for you. A lot of photographers (e.g., on Instagram) stick purely to representation, and that’s fine, like a preference for mostly green or blue shirts.