Here's how to make a realistic glass sphere using Adobe Photoshop. I am using CS2, but any version after 6 will work. (I have not tried on any previous versions before 6)
Step 1: What You Will Need...
You will need:
A desktop or laptop computer
...and that's it!
Step 2: Getting Started...
You will need to open a new file in Photoshop. It will need to have a black background, and the document size can be anything as long as it is square. ex.: 500 x 500 pixels.
Once you have done this, you must create a lens flare. Just click "Filter" on the title bar, then click "Render" on the dropdown menu, then "Lens Flare" on the next dropdown menu. Leave the default settings as they are. If you have used this filter before, the flare must be slightly upper right or left of center.
Step 3: Making the Sphere...
Now, we have to make this flat lens flare look 3d.
Select "Filter", then click "Distort", then "Polar Coordinates". Click the "Polar to Rectangular" button, then click "OK".
Next, we need to rotate the image 180 degrees.
Click "Image", then "Rotate Canvas", and 180.
Now, we do the polar coordinates again, but this time we will click the "Rectangular to Polar" button.
Now, it should be looking 3 dimensional.
Step 4: Cleaning It Up...
Use the Elliptical Marquee tool to select your sphere. Then, click "Select", then Inverse. Hit the delete key to remove the excess mush that is around the outside. You can stop at this point, or you can make it better.
You can create a new layer, and move it underneath your first one. (double click the layer if it is locked)
Then, fill the layer with black, then click back onto your sphere layer and reselect your previous selection, and delete the white background.
You can make it even more realistic by overlaying a photo, and blurring the edges.
The end result should look something like my last two pics.
I hope you have enjoyed this instructable, and I also hope it was easy to follow.
Go to the next page to see what you can do with your newly acquired Photoshop skillz!
Step 5: Examples
Here is a wallpaper I made using this method.
NutanN made it!