Photoshop

I especially like the ability to "play" with photos. Take a look at this:

This is the view from the west rim of the Royal Gorge in Cañon City, Colorado.

And this is what the view should look like.

Making these changes was the work of less than 30 minutes. 

The first thing I did was to select out the sky and darken it a bit. This is especially easy ever since Photoshop introduced the "magnetic lasso" tool. You place this tool at the boundary between two significantly different colors, like the mountains and the sky, and click and trace the line between the two areas of the photo. As long as you keep the lasso reasonably close to the boundary, Photoshop places the selection EXACTLY on that boundary. It follows each minor wiggle and wander of the boundary precisely.  After the sky is selected, it's usually necessary to go back, zoom in on the boundary and make very minor corrections. But, instead of taking many minutes to trace this selection out, it only takes a minute or two.

Next, it was just a matter of using the cloning tool to copy bits and pieces of the picture on top of the buildings in the foreground. I used both the rock face of the gorge and the foreground trees to accomplish this.

Layers

What are layers? Did you ever see how they make cartoons? First they paint a background scene. Then on a clear piece of material they paint each individual picture that comprises the movement of a character in the cartoon. These are called cells. Then, they photograph the background with the Cell overlay of the character in the first movement position for that character. Next they leave the background alone, but replace  the first cell with successive cells. In this way, they greatly reduce workload by only having to paint the background scene once.

Well that's what layers are all about in Photoshop. You can "paint" individual objects into different layers. The amount of time this saves is phenomenal. Especially if you make a mistake. 

In the pre-layer days I did some of this stuff and you had to be very carefull when you tried something like this. You see, once you pasted in the object to be inserted, it was part of the picture. If you needed to move it a bit you would be uncovering blank background.

However, with layers you can drop an inserted object into its own layer. Then you can move it around without affecting any other part of the picture.

Here's a picture of my father trying out for a part in 2001: A Space Odyssey. Just kidding there. This is just a good example of layers.

First off, I didn't have a picture of my dad that was quite right. In one picture (99% of the above head shot) he had a sufficiently grave expression and was looking to the side. Great I was on my way. But, he chin was resting on his hand and his fingers were in the way.

I had another picture of him looking to the side, with no hand in the way, but he was laughing uproariously. It didn't seem like the right picture for this insert. So...

I scanned in (actually captured from a DVD) the main picture of the astronauts discussing HAL from the movie. 

Next I dropped my dad with offending fingers into this picture in Photoshop on another layer.

Next I dropped the photo of laughing dad into a third layer.

Then, I had to do some color, brightness, and contrast  matching so the laughing chin matched appearance of the serious face.

The laughing chin was too big. So I selected that layer alone and resized it until it overlay the grave expression with proper proportions.

Next, I cut out everything on the laughing chin photo except the chin itself (got rid of the rest of his face).

The angle of the chin in one picture didn't match the other. In one, he was leaning back laughing, in the other he was looking absolutely level to the side. So, again I selected only the chin layer and rotated it until it matched the orientation of the grave face.

Next I erased all the background from the grave expression picture using the magnetic lasso tool discussed above. Then I carefully removed the offending chin and fingers from the grave expression picture. 

Next, I carefully moved the substitute chin into position. 

OK, the grave expression and the new chin looked fine. So, I linked those two layers together in Photoshop and told the program to merge them. The result, I now had a picture comprising two layers. One, the background scene of the movie and two a perfectly normal appearing shot of my dad gazing to the side.

Oh no, dad's head was MUCH bigger than those of the astronauts, and his face was absolutely level looking to the side. So ...

First I resized dad down to just a tiny bit too big for the picture. Next, I started playing around with rotating his head so it was tilted down somewhat and appeared more naturally a part of the actor's body he was soon going to replace. Actually I pretty much just matched the angle of dad's head with that of Kier Dullea (the actor he is replacing).

Once that was done I started resizing his head so that it looked to be properly proportioned to the body of Kier. Again, I pretty much just tried to match the dimensions of dad's head to Kier's.