I shot the photo scrap for this little piece at a Plein Air Artists Colorado paint out in Taos almost 2 years ago. The directionality of the painters at the easels is interesting enough but without the contrast of the dark bluff behind their highlighted forms this would just be, so - so photo scrap.
I am always looking for scenes with strong value that translates to good patterns of light and dark.
Can you see strong value shapes in your color photos? Not sure? Take them to a copier and print them out in black and white. A color photo with good value will pop in black and white. Once you see clearly - exactly what you are looking for - look for more photos with the same sensibility: strong darks and strong lights. You will eyes will recognized what it is and your photos will get better and lend themselves more readily to paintings that communicate the sense of light.
And isn't that what we all are going for?