An empty or dull sky, whether white or blue, in a large part of an image is a vaste of space in a composition. You can’t necessarily wait on site for clouds to come or go, though ! One of our modern-days solution is to artificially replace parts of the sky.
Shoot “stock” skies
During a photo trip, we often focus on the landscapes around us, and less on the skyscapes above us. However, wonderful cloudscapes could happen while the land under might not be as interesting. Be sure to shoot some of those clouds, for they might be useful later. In other terms, build a cloud photos stock.
You may want to shoot skies from a variety of focal lengths and sun orientations. Any composition will look way more natural if all parts of the photo were shot with about the same light and focal length.
(16mm, sun from the left side)
(24mm, sun from above)
Here is an example of a photo I like a lot, except it was taken under a light rain. Correct ground exposure required to over-expose the sky, but the clouds were quite uniformly grey and shapeless anyway. I decided to add a few strikes of blue and grey shades to fill the white void left.
I chose to compose from a photo I shot earlier under grey-but-not-as-grey skies :
First open both photos, then select the sky area you wish to move and copy it from the cloud reference photo to the base photo. Carefully align both horizons, so that the perspective won’t look unrealistic.
With a layer mask, smooth down the clouds layer lower edges to have a glimpse of what the result would look like. You can reduce the clouds layer opacity to better see what you are erasing. Use a soft edge brush to smooth the erasing.
If you are still confident with the outcome, continue erasing the parts that overlay with the base photo. Don’t hesitate to shrink your brush when it comes to detailed areas, but in the end you may need to sacrifice some parts of the clouds layer if some details are too difficult to extract, like branches or grass.
To correct this you can either adjust the levels of the under layer, adjust the levels of the clouds layer, delete more of the clouds with a large brush to ease the gray scaling, or a little bit of all that :
I actually darkened the sky in the base layer, lightened a bit the cloud layer, and erased some of the clouds in the upper corners.
What about blue sky ?
This same technique also applies to fill a rather completely empty sky !