Abstract Categories

I enjoy abstract photography, but what exactly makes a photograph abstract in nature? I find myself thinking about this from time to time.....like when I am keywording images in Lightroom and deciding whether to apply the abstract tag.

To me, there seems to be several types of abstract images:

1) Images that appear to consist solely of light and shape with no seeming connection to 'reality', so that the viewer has no ability to tell what the image is a 'picture of'. Here is an example I found on Flickr by photographer Stephen Tuck.

2) Images that consist of light and shape but do have a connection to 'reality'. An example of this would be this image I posted a few weeks back which utilized camera motion to make a grove of trees into an abstract. Though the photo clearly seems abstract to me, it is also pretty clear that trees are the subject.

3) Images that consist of concrete shape and form but, because of extreme magnification, the origin of that concrete shape and form remains obscure. An example of this would be a greater than 1x macro photograph of an insect's eye.

4) Finally, there is the type of abstract image that I like best, even if some might quibble with its being characterized as abstract. These are images where the object being photographed is not rendered uncertain by extreme magnification, but the image itself is not 'about' the object being photographed. An example of this would be my photo below entitled 'Buds'. While it is clear that the image is composed of plant buds, the image is really not about the buds at all but, rather, is about the repetitive shapes and forms they make.

"Buds"
Copyright Howard Grill

There are likely other types of abstracts as well, but these are the ones that come to my mind. If you can think of other categories, please feel free to share them in the comments section!