I rarely sketch out my ideas, because blending sources this way is not very complicated, but it is important to have a feel of what you want to create, as well as the atmosphere, before you actually start working.
Like with any image in which sources are being used, selections are the first stage. We want to isolate every source so that we can create our own composition.
Below you can see the background sources and the main object, in this case, the turtle.
When an image is imported into photoshop, it's known as a Background Layer This means that there is no layer below that one. To be able to remove the sky from Night Fate's background, we need to make this a workable layer.
The Pen Tool is my preferred tool for extracting an object, because it's a very versatile tool that once mastered can be used to accomplish almost anything. Draw a path by pointing and clicking around the area you want to delete. The selection doesn't have to be perfect, photoshop has an extensive range of Edge Refining tools that will make any mistakes easy to clear.
Delete the original sky, like shown below, so that the new sky can be imported. An interesting sky is very important to most images, because it helps create an atmosphere. For images with a "Happy" mood, a clear or partly cloudy blue sky works well. However, for a dark and almost depressing image, a stormy sky conveys the right emotions. With this image i chose a sunset, because it shows a slow passage of time.
Once the original sky has been removed, select the new sky and use Ctrl+C to copy it, then go back to the desert background image and press Ctrl+V
Once the new sky is in your image, press Ctrl+T and resize the sky to fit over the image. It's VERY important to hold the SHIFT key down while resizing, to maintain the original proportions of the image.
Next, move the 'Sky' layer underneath the 'Desert Layer' and press Ctrl+J to duplicate the 'Sky' layer.
Then go to Filter - Blur - Average
The 'Sky Copy' layer is now the average colour of that sky, with no differing tones. We'll use this layer to match the hues between the Desert and the Sky.
Move the 'Sky Copy' layer to the top, and hold the ALT key down. Next, click on the dividing line between the 'Sky Copy' and the 'Desert' layer. This creates a linked layer which acts like a layer mask.
I usually change the blend mode to 'Soft Light' or 'Colour' , but in this case the two blend modes were not strong enough. The blend mode 'Overlay' worked well, and that was the one that was chosen.
My Pen Tool selection was quite rough, and some of the original sky could still be seen around the edges. This is the perfect time to use on one of Photoshop's most hidden features, the "Defringe" layer feature. The Defringe option almost perfectly removes any thing white halo around a selected objects.
It can be found under Layer - Matting - Defringe
A value of 1 pixel was chosen.
Below you can see the image so far. As you can see, the hues between the sky and desert match together, and there is no white halo around the image.
The next stages show the slight editing of the background, as well as adding all the different sources.
The perspective of the Desert layer is different to that of the turtle layer. This can be simply changed by pressing Ctrl+T , next right click and press "Perspective" and pull the bottom two corners as shown below.
Using the Pen Tool, make a selection around the turtle, then press Ctrl+T and resize and move it into position.
The next step is to match the lighting of the turtle to the rest of the image. Create a new layer and call it "Lighting" next link the layer with a clipping mask like described in Step 7.
Using a soft brush at about 70% opacity, begin to build up lighting and shadow layers, once you're done, change the blend mode to "Soft Light"
This creates a subtle change in lighting.
Next create another linked layer above the "Lighting" layer and name it "Inner Shadows", then using a low opacity brush paint along the bottom of the turtle. This again helps to create a subtle change in lighting.
Of course, no image would look at all realistic without a shadow. Paint a shadow along the bottom edge of the turtle on a new layer below the "Turtle" layer. Name this layer "Shadows".
Once you're done, blur this layer as shown below. This helps to create a nice, soft shadow.
Most of my shadows consist of two or three layers. Add a new layer named "Shadows 2" above the original shadow layer, then paint a shadow that covers a larger area around the turtle, like shown below. This layer needs to be blurred almost twice as much as the first shadow was.
Once you've done that, change the blend mode to "Soft Light"
This step shows how the image looks so far. As you can see the lighting on the turtle closely matches that of the background and a convincing shadow is in place.
The next few steps are very similar to ones shown above, with layers being linked and blended together with the layer mask.
Select the sand roughly and copy and paste it into the main composition, then move this new layer underneath the lighting layers on the turtle.
Resize the "Sand" layer to fit the turtle and add a layer mask. Use this layer mask to delete the areas where there is no shell.
Do the same with the "Grass" layer.
Use the Layer Masks to make a transition between the grass and sand layers.
Import the pre-masked tree files into your composition and resize them to fit around the shell. The trees were added to show the difference in dimensions. This shows that either the turtle is huge, or the trees are tiny.
Remove the lower parts of the trees and in a similar way to the shadows on the turtle, add the shadow for each tree.
Use a soft brush to pain the new lighting on the trees, add each of these on a new linked layer with a Clipping Mask. Again, i'll spare you the details because they've already been described.
Below you can see the image so far.
Roughly select the Stream and import it into the composition, then resize it on the turtle's shell. Add a layer mask to this layer so that it can be blended better with the rest of the image.
Erase the unnecessary parts using the layer mask, I also changed the lighting of the stream.
In this step, using the same steps as above, i added the gazelles and the elephants, I also grouped each object separately for a more organised layers palette.
The next few layers are used to match the colours of the scene, as well as to create a mood for the image. As mentioned below, i've created custom gradients that I use most of the time in my images, but i also use some default ones.
Add a new Gradient Map adjustment layer, and click on the default black and white gradient to enter the Gradient Editor.
Add two adjustment layers, one going from Black to Brown to White and another going from Black to Blue to White.
Change the Brown layer to "Colour" and place it below the Blue one, and change the Blue gradient map to "Soft Light"
Now, select both those gradient maps and group them by pressing Ctrl+G
Change the opacity to 37%
Next add another custom gradient like the one shown below, this gradient can vary, as long as it goes from a dark colour to a light colour. Change the blend mode to Colour and lower the Opacity to 38%
Now add two default gradient maps. The Black and White gradient map should be below the Violet and Orange gradient map. Change the blend mode to the Violet and Orange gradient map to "Soft Light" , then group both layers and lower the opacity to 26%
Now add a Colour Balance adjustment layer to give it a different overall hue, change the blend mode to Darken and slightly lower the opacity.
Add a Black and White adjustment layer and change the options as shown below, and lower the opacity. Next, add a Photo Filter adjustment level, keep it at the default values.
Using a low opacity brush on a new layer, paint the overall lighting adjustments like shown below. Once you're done, the blend mode should be changed to "Soft Light" and the Opacity slightly lowered.
On a new layer paint a simple vignette with a large soft brush, lower the opacity to 78%
Next, give the image a "Soft Glow" effect by merging all the layers onto a single layer above the others. Do this by simultaneously pressing Ctrl+Shift+Alt+E
Next apply a Gaussian Blur to this layer.
Change the blend mode to "Soft Light" and lower the Opacity to around 50%
Below you can see the difference before and after applying the colour and lighting adjustments.
That's it! The image is complete.
I hope this tutorial helped you understand the way i match colours and blend images. Thank you to everyone on this site who has taught me so much. :)