Alan, great shot(s).
I'm moving away from HDR and trying to take advantage of my a7RIII's dynamic range. I wanted to stay at this lens' sweet spot of f/8, so I ended up at ISO 200 and 1/15-sec. handheld. I know that the dynamic range of the RAW file exceed the DR of the in-camera preview jpeg by around one stop, so I purposely over expose the highlights, but less than a stop. In post, only a slight adjustment is needed to pull down the highlights. I would have rather shot at ISO 100, or less, but I think that I was near the in-body-stabilization's limit. I raised Contrast in post to show off some of the dark cloud details. This is approximately how the scene looked to my eyes:
Twilight Over Cherry Creek Reservoir by
David Stephens, on Flickr
Another stop or so of native dynamic range and I don't think we'll need HDR. Sorry for the repeat image, but this one had the most DR of any of my recent shots.