HOW TO: Focus Stacking done easy with Photoshop CS4 or CS5
Elinchrom Ranger Quadras were set up on either side of the tent. The left hand light was 3:1 with a 3200K gel on it, and the Left hand had the bigger power at 1:3 with no gel on it.
7 shots were taken of this with focus adjusted between each shot. Each image was imported via ACR Raw into CS5 Photoshop.
All images were then stacked by using the command found under the File Menu under Scripts>Load Files into Stack... (this will work for CS4 as well). Because I directly imported all files into Photoshop they should all be opened as separate files. You will then hit the Add Open Files button to load all the files into one document as layers. Make sure all the check boxes are off. You can skip a step if you own Lightroom and use the edit as layers on all the files selected.
Select all the layers in the layers palette and then under the Edit file command, select Auto-Align Layers... Choose the default Auto selection and hit OK. Make sure all check boxes are off.
Next under the same menu command, select Auto-Blend Layers... Choose the Stack option, and this time check the box that says Seamless Tones and Colours
Flatten the Layers and you should have an image like this with everything in focus. You do need a tripod, as well, to ensure your shots are pretty much aligned. With Photoshop, it does eliminate the need to own an expensive tilt-shift lens. As you can tell by these instructions, it's pretty easy to pull off your own focus stack.