Up in the mountains field shooting, writeups follow when I’m back in a week or so.
Scenes like this make me wish for a true 16 bits of dynamic range: precision exposure is mandatory to capture the full range of detail from the dark shadows to the bright clouds (which the D810 did well). Another 1.5 stops would allow for a little less concern in making the exposure exactly right (also, note that auto exposure is almost always a disaster on scenes like this, careful study of a test exposure’s histogram is how I “nail” the exposure on a scene like this).
Update: the problem is really poor camera histograms, not dynamic range; checking the NEF with RawDigger, it turns out that another 1/2 stop of headroom remained unused! See comments on the sunflower image on camera histograms.
This image as shown had a big shadow boost, which is what dynamic range is all about; the ability to retain highlights while also preserving shadow detail that can be brightened considerably with minimal noise: the D810 does that superbly well at ISO 64 as here, in this image with extreme contrast. ISO 64 on the D810 is the best image I have ever seen on a DSLR (the Pentax 645Z seems to be as good and even a bit better as its large pixels would imply).
Daily thunderstorms are the most unusual I’ve experienced, with the lighting varying from bright sunlight to dull overcast to flipping between in matters of seconds. Fantastic, if a bit frustrating and impossible to compare lenses.
The image below took a massive +100 Shadows and -100 Highlights in ACR conversion; amazingly the D810 captured the entire contrast range even into those too-bright-too-look-at clouds right down into the darkest under-plant shadows. Checking the NEF file with RawDigger, there is/was an entire full stop of headroom still available.
I was cautious on exposure, but it is difficult to be sure: like all DSLRs, the Nikon histogram implementation bakes in a moderate-gamut colorspace (AdobeRGB), an inertial design stupidity borne of dogmatic “everyone shoots JPEG” thinking which continues to this day. Those bright yellow sunflowers go out of gamut a full 1 to 1.5 stops early, thus the camera indicates “highlights blown” when there is ample room left to expose. There is no way to be sure. Bracketing is one solution, but I was shooting an aperture series and did not want to double-up or triple-up on every aperture.
Both images (above and below) adjusted on laptop screen in the field; color balance and contrast not my usual and might be off slightly.