I was shooting this girl in the moat window of Castle McCullouch in High Point, North Carolina. I had an entire lighting set up, but then I noticed how nicely the natural pre-twighlight was falling on her. So I pulled the radio trigger off the camera and very quickly shot a bunch of all natural light frames.
The end result looks pretty good, I think. But, if I'd been thinking ahead and had a flash ready for the situation, I could have saved myself a lot of agony in post.
I spend a lot of time burning down the background and slate floor, and dodging her, to get this right (I also dropped the white balance near to tungsten to get the lovely blue). Lots of manipulation like on a relatively high ISO exposure (1600) emphasizes the noise, both chroma and luminance.
What I really needed wasn't much. Dropping the exposure by a stop, say by cutting the ISO to 800, would have made working with the hot areas easier.
Of course, doing that would have killed the detail in her clothes too much. A gridded and lightly blue gelled Canon 550EX class speedlight cut down to 1/16th or 1/32nd power (2 -3 stops down for the ETTL crowd) could have put in just enough light into the area from her knee to her hat to pull out the details without overwhelming the scene.
That combo would have greatly reduced my post-processing workload, and improved the image quality noticeably.