I'm not sure it can be defined in the strict sense, in fact having read the things I linked to, I am sure it can't be defined with any certainty, but the nature of a discussion on art is that people can give their understanding as it relates to their own views and then through the process of discussion it is possible to learn things, expand your horizons and maybe think about things in a different way, I like that and have no problem with tough conversations, none of us are born with knowledge, we need to learn it, shared experiences and listening to others views are a good way.
Your previous post about black point, tonal variations etc. is how you chose to describe your understanding, I read that and can't relate to it personally in connection with the artistic idea of sublime, I can relate to it as your description of what you want to see and achieve with your work to create an image that you regard as sublime within your own definition of course, I still feel that they are different things.
Now I am reading things that refer to sublime I am forming opinions on what it relates to, and how it differs to a literal explanation of the word. For example, you could take a shot of your kids first smile or first steps, you would rightly feel that the image is sublime because of the feeling it gives you, you could even be in awe at the miracle of birth and development, new experiences etc. etc. What I am picking up from reading stuff is that mainly it refers to landscapes, traditionally it was vast alpine scenes, where the awe is leaning towards the frightening, the expanse, the power within the image, maybe it could be an image taken from a precipice, maybe the viewpoint is one that simply is so vast that it prompts "fear" as you realise how small you are in the big scheme of things. In modern stuff, the notion appears to have moved towards the industrial impact within nature, the dark influence of man for example as per the Burtynsky work but not limited to that, I have seen images of power stations billowing steam within otherwise pristine landscapes, vast areas levelled by mining etc. I am still only scratching the surface so far.
The reason this came up is that I got a comment on some work I produced with no concept of sublime, on a trip to Lofoten Islands recently, I was in awe of the landscape, obviously it is a stunning place, but more than that, what struck me was the fragility of life in the place, how hard it is now and how much harder it would have been hundreds of years ago without our modern amenities. The images I produced are not in any way dynamic enough to be considered sublime as in this context and certainly not in the dictionary definition, they are not pretty, they are dark and stark, the feeling I got from being there. But now I can see that what attracted me to the scenes that I photographed could lead me to look deeper at sublime and maybe influence what I photograph in the future. The small shack I photographed dominated by the mountain backdrop spoke to me at the time, I was amazed that someone could live there, a family could have been raised there, kids schooled, played outside in the 24hr darkness of winter and so on, maybe those feelings and the reason for taking the shot could lead me to learn new things. On the second day I was there, we had an enormous snow storm, I sat in the hotel bar looking out the window as the wind battered and the snow blew horizontally, the thought of the years that little house had stood there, the amount of storms the occupants would have witnessed under that tin room, I guess you could call that idea as frightening.
Anyway, I’m rambling again, this may not be the place to discuss this stuff, no harm done. If people have a view then it would be good to read how it differs from mine, or not as the case may be.