Sky/ground blending in images with high light pollution on the horizon

Here is an example of how to adjust the sky/ground transition in an image with very strong light pollution on the horizon:

1. Result with default adjustments

As there is a lot of light pollution on the horizon, the default sky/ground blending does not quite manage to solve this particular situation, so the sky/ground transition does not look natural at all. As always, the first thing to do is to check that the general adjustments of the sky/ground transition are selected (red arrow).

2. Apply a transformation to the image so that most of the light pollution falls below the horizon

Applying a geometric transformation to the sky image is a very effective way to solve the problem of intense light pollution on the horizon. Thus, by applying a small stretch (both vertically and horizontally) to the sky image and, in addition, shifting the sky all the way down (+100), most of the light pollution is below the horizon and, therefore, no longer affects the sky/ground blending.

3. Adjusting the sky transition

The radius of the sky transition is increased to definitively solve the problem of intense light pollution on the horizon. Thus, the transition zone of the sky is wider and the light discontinuities caused by all the light pollution concentrated in the horizon zone are better covered.

4. Adjusting the exposure balance

It was decided to decrease the exposure balance a little (by half a stop) to equalize the light intensity of the horizon area with the rest of the sky.

5. Adjusting the ground transition

Finally, in this case it is decided to reduce a little the radius of the sky transition to make the reflections of the background lights more visible (as the ground transition zone is narrower).

Enlarged detail of the horizon area to show the result of the sky/ground blending.

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