Above is the final image created. In this tutorial I'll take you through the steps involved in creating this image, spending just enough time on the photoshop technicalities so you can create a completely different image using a similar approach. I try to put links in the places where one might want more detail of how to do certain tasks in photoshop. The pictures do most of the talking with the words mainly here to fill in the gaps of the how and the why.
I guess you could call this the absurdly rough stage. As you can see I have an incredibly rough sketch. The plan going into this piece was to create a forest populated with houses in trees. My sketch outlines I'll have a bigger house in a tree as the point of focus in the upper right third, a supporting smaller house on the left side and possibly a hobbit hole-esque hut down below. Normally I try to make more detailed sketches as it saves a lot of time later on. With this picture I was foolish and did not.
I decided rather then taking the photographs myself I'd see what I could create using only creative commons images on flickr. It's a great source for finding images (better then google as far as I'm concerned in the higher res department). I went on flickr grabbing huts, adobes, gnarled trees, forests, some neat mountainous backgrounds and other images. Before even starting the image I had over a hundred images to draw from. It was a good starting point, but I had no doubt more images would be needed as the details started to become clear.
While this might initially look like a massive jump from step 1, after a rough glance it's fairly simple figuring out how I arrived here. The house and main tree trunk are where I had sketched them out. Below them is one approach to the hobbit hole type dwelling. In the foreground I'm tossing around the idea of a bridge and in the background I've put a couple of mountains. Most likely I'll be taking those mountains out or almost completely covering them up, but I like to cover all whitespace as quickly as possible. I've done very loose tracing in this step as the plan is to mainly get the placing. After that I can spend more time really getting a good mask on all the images. Detailed masks take time, so I try to only do them when I know they'll be used.
In photoshop I like to check the 'auto-select' box for the move tool at this stage as that way I can just press a layer and move it around. When I'm not doing that I'll right click in the move tool over the image and pick from the drop down. I tend to use the layer palette as little as possible and rarely name layers. When I start to get a couple hundred layers with 8 or 9 overlapping any given part of the image I'll name a few of the key layers. Before that, I find it's just a waste of time only needed by the neat freaks of the world
The plan from the start was to have a forest of tree houses, not just one, so I start adding in background houses. I found a bunch of nice looking trunks and some houses that could stand on trees and went about combining them. I added in a ground house towards the bottom as I found the ground was looking boring. I added some leaves to the hobbit hole and the chimney and window to the key house for the same reason. The house added in front on the left was to fill what was previously dead space, and the viney forest thing in the background was put there in hopes to eventually build many, many more trees.
I spent some time at this stage getting a decent mask on the left tree as I liked it and saw it staying. With all of the cuts I'm using masks rather then deleting out part of the layer as I might want to add part of a layer back. A good example of adding part of the layer back is I added back in the roots of the main tree (the tree is flipped vertically so the roots are touching the key house). On top of loose cutting I'm also not touching color correction. I save that until the very end.
I cut out the chimney and added in a shadow. Using a mask I got rid of the non-chimney parts of the layer. Then I duplicated the chimney layer, taking the lightness (In Hue/Saturation - Ctrl + U) down to completely dark which turned it black. I then placed that layer behind the chimney layer (Ctrl + [ for those looking to avoid the layers palette). After that I used the gaussian blur filter (Filters>Blur>Gaussian Blur) to blur the layer, and probably brought down the opacity to 80%. Steps similar to these were needed for just about every image used in this picture.
The image was starting to feel incredibly busy, with too many trees and not nearly enough to focus on. I made most of the house tree things smaller, pushing them further back, and also got rid of the bridge as I didn't see it doing too much in the end. Additonally I pushed the mountains up. I turned the primary house into a secondary house, and brought in another house to become the new primary house. I added the leaves at top of the new house, the six or seven varieties of roots at the bottom, and placed in some vines on the right. A trunk was still needed, but even in this state of chaos the image started to become clearer. It was the scraping of a lot of work and basically starting over at this stage that makes detailed sketches so important.
I shifted layers around in this stage, trying to get the lines of the composition pointing to the main tree house. I added in a trunk and a man inside the window and raised up another mountain in the top right, sticking a mausoleum on top. Again, this is because I don't like dead space for better or worse. I'm still not paying attention to colors, as I know as long as there's enough color depth those can all be adjusted.
I moved a few pieces slightly around in order to get rid of strange floating trunks, trying to pretend I care a little about perspective. To be honest, I do, which is a hard thing to pay attention to in the world of collages, especially collages where I didn't take the photographs myself. I took out the man, and also the wires in the top left building. While taking the man out was as easy as turning off a layer, there was a great deal of stamp tooling in the wire removal task. I never use the stamp tool on the layer I'm correcting. Instead I create a new layer above it, and with Sample All Layers chosen I work on the new layer. I continue to make more new empty layers as I make finer corrections. That way erasing is the same as undoing and there can be back and forth.
I also color corrected and added in some more shadows. It's easier to take out color then add in color, so unfortunately that's what I ended up doing. I ran into problems, even after predicting it, in the images that had absolute blacks or absolute whites. Those images were either under or overexposed. With no color information to draw on I needed to either cover those parts up with another image, as I did in that main swarm of branches in the middle of the piece, or paint in a gel of the right color. By Gel, I mean a fill layer on a low opacity set to only affect the layer below it (Ctrl+Alt+G.) I use a lot of color adjustment layers so I can go back and forth, mostly using Curves, Hue/Saturation, and Color Balance. Some times I'll use levels to take away the blacks or whites. I set the color adjustment layer to affect only the layer below (Ctrl + Alt + G).
I used a number of yellow layers masked just right of varying degrees of bluriness mostly on screen to create the yellow glow from within. I took down the brightness of the root tangle by painting a brown layer and turning the opacity down on to p of them. I also added in the pensive man, which I painted in acrylics by hand and then scanned in. I could have simply cut out a photograph. It arguably might have looked just as good or better, but where's the fun in that? Also, I slapped a texture of a green and blue crumpled piece of paper over the top of the whole image on a low opacity, possibly on Soft Light. The rest of the changes are slight adjustments, with just enough to make the picture work.
I still think the picture has a ways to go, and once I'm less sick of it I'll go for a part nine. In the meantime, I hope this tutorial was helpful. If you have any questions or if you have a crit I should take to heart please don't hesitate to comment below.