An ordinary photographer might be put off by a rainy day, but a real fan seizes upon the possibility of getting photos with_atmosphere_. On a rainy weekend recently we drove to the Sonoma Coast. That’s the coast with the Pacific a couple hours north of San Francisco. We stopped at a small roadside pull-off a hundred yards north of Gilbert Beach.

This short video clip, taken with pocket camera, gives an idea of the location:

Remember, this is not a video blog, so of course the video is lousy.

I took two still frames to be stitched into a vertical panorama.

Usually auto exposure helps, but this time the misty portion of the image (right) is overexposed to pure white. That makes the vegetation in the other frame (left) autoexposed without the white sky, relatively too light. The task in Photoshop™ is then to darken the pure white sky to restore some of that rainy day atmosphere, then get the vegetation in the lower part of the spliced panorama to reasonably match the upper.

Here is the histogram of the image with the mist. The bright pixels go all the way to the maximum on the right end of the graph. One might think that Enhance > Lighting > Shadows/Highlights would make the white mist darker. Here we darken the highlights by 50%. Notice that the rocks get darker.

The mist, however, stays white, as shown in the modified histogram.

Photoshop is maintaining the contrast of the image by keeping the brightest part of the image pure white. Usually, we would want the contrast preserved, but in this image a darker mist better captures the low key scene. The Levels and Brightness control do the same thing, preserving pure white. I went back to the original image.

The trick is to select the white area and then fill it with 8% opaque black. Here is the Edit > Fill menu that does that. The foreground color was set to (0,0,0) black.

A single 8% fill was not dark enough, so I reselected, feathered the edges of the selection, and did another 8% fill.

The two images were stitched automatically without a problem. I finished the touchup my selecting the right portion of the image foreground, feathering the selection, then darkening using the Levels control. The result is (click to enlarge):

Once you understand the trick it can be applied quickly. It’s better to underestimate the darkening required and then fill repeatedly to get the desired effect.