Replacing a Dull Gray Sky
With a Bright Sky


We frequently take photographs on days that are dull and gray. The image can be much improved if we could change the sky to a brighter blue sky with some nice fluffy clouds in it. With a computer and with Photoshop we can do this. And it is fairly easy in many cases.

The first step in the process is to develope a library of photographs of clouds and skies. You will want morning skies, evening skies, skies with very nice clouds, cloudless Arizona skies. When you start your collection of sky pictures you will soon discover that sky blue is not a single color. And you will want to have skies of many colors to match the mood and lighting conditions of the picture you are working on.

Select and Delete the Sky

  • Open the file "DenmarkThatchedRoof.jpg". This image is shown on the right on this page.
  • Make a duplicate layer of the original with the command "Layer -- Duplicate Layer". I chose the name "Base" for the duplicate layer.
  • With the magic wand tool select the sky. As you already know, each image is different as to what settings for the magic wand you should use. However I found that a tolerance of 30 worked well. I also clicked off "Contiguous" to allow it to pick up some of the sky in the trees.
  • Remove selected areas that are not sky. With the settings I used there is a small area on the left edge near the bottom of the picture. Use the polygonal lasso tool and be sure to click on the "subtract from selection" button.
  • Normally you will get better results on a selection if you expand and feather it.
    • Expand the selection with the command "Select - Modify - Expand". Use only one or two pixels in this case to avoid losing some of the foliage.
    • Feather the selection (make the edges softer) with the command "Select - Feather" and again choose one or two pixels.
  • Remove the sky from the Base layer with the delete key. Make sure the Base layer is the active layer. If the Background layer is visible you will not likely be able to tell the difference. So click on the "eye" of the Background layer to make it disappear. The checkerboard pattern where the sky was indicates it has been erased. Your image should appear somewhat like the one on the right.

Bring In the New Sky

  • Open the file "OsloClouds.jpg". This image is shown on the right of this page. It will become the sky in the Thatched Roof image.
  • Using the zoom tool, click on the Minus button and click on the Oslo Cloud image a couple of times to make it appear smaller.
  • With the Oslo Cloud image active, select the entire image with the command "Select - All". (For a shortcut you may use the keystroke command control-A)
  • Put the selection in the windows clipboard with the with the command "Edit - Copy" (the keyboard shortcut is control-C)
  • Click on the top window bar of the Thatched Roof image to make it active. In the layers window make the Background layer active.
  • Copy the Oslo Cloud image into the Thatched Roof image with the command "Edit-Paste". The Oslo Cloud image will become a layer just above the Background layer, which was active. In this case it will also be just below the Base layer which has its sky removed.
  • Close the Oslo Clouds image. We no longer need it.
  • In this sky image the sky is darker at the top than at the bottom. That is frequent -- the sky will appear lighter near the horizon. Also no clouds appear in the image.
    • To correct this, with the sky layer active, click on the move tool.
    • Uncheck "Auto Select Layer" and check "Show Bounding Box".
    • Click and drag the cloud layer up until the clouds and sky in the picture look as you would like them to.
    • You may also expand the cloud layer by clicking on the edge buttons and moving them outward.

Brighten the Foreground

It is frequently the case that when a photograph is taken on a cloudy day the foreground looks a little dull. If you then replace the cloudy sky with a bright sky the foreground looks out of place with the bright sky. To make the foreground look like it is in the sunshine you need to warm it up a little.
  • Make the Base layer active.
  • Make an Hue/Saturation adjustment layer with the command "Layer - New Adjustment Layer - Hue/Saturation". In the "New Layer" dialog box check "Group With Previous Layer". This will make the adjustments apply only to the Base layer.
  • Adjust the Saturation and the Hue in the Hue/Saturation dialog box. A suggestion is to use 6 for hue and 30 for saturation. This is personal taste.
  • Now make a Levels adjustment layer with the command "Layer - New Adjustment Layer - Levels". Again check "Group With Previous Layer"
  • Adjust the levels as you would like them. Remember you are working only on the foreground Base layer.
  • You may also do the same thing with a brightness and contrast layer if you wish.
  • These steps could also have been done with the Base layer active and using the "Enhance" command in PSE or the "Image - Adjustments" command in PSCS.







Unedited image of a thatched roof home
in a village in Denmark







The Thatched Roof home with the gray
sky completely removed.  Note the
checkerboard pattern







A sky picture, taken for the purpose
of sky replacement in other images.








The edited photograph, complete with
new sky and brightened foreground.

Finish Up and Save

  • Flatten the image (remove layers) with the command "Layer - Flatten Image".
  • Sharpen your image with the command "Filter - Sharpen - Unsharp Mask". The settings of 125 for Amount, 1.5 for Radius and 4 for Threshold are the standard settings. Adjust the amount as you see fit. Do not oversharpen.
  • Note: In Photoshop CS2 you may wish to sharpen using the command "Filter - Sharpen - Smart Sharpen".
  • Save your corrected image. Take care not to save it over your original