I was actually wondering how you'd managed to get such a sharp image with what seemed like natural light. Then I read what you did. Looks like you've perfected that technique then...
Care to share the details?
Thanks

It's not actually that hard! I love how sharp the images end up
Guide
How to do focus stacking in Photoshop CS6 Extended, with Canon raw pictures:
Open all pictures. I assume they will be opened in Camera Raw.
In Camera Raw, select one of the pictures that is in the middle of the stack, and is the best to look at when adjusting the pictures.
Click on the button "Select All". You can now adjust the setting for all the pictures at once, while looking at the best picture.
Adjust the settings of all the pictures to your liking.
Click on "Open Images" when ready to go on to Photoshop.
File / Automate / Photomerge...
Layout = Auto
Click on button Add Open Files
Uncheck checkbox Blend Images Together
Click OK
Select all the layers. The top layer is selected, so you only have to shift-click on the bottom layer to do this.
Edit / Auto-Blend Layers...
Select Stack Images if it isn't selected.
Check Seamless Tones and Colors if it isn't checked.
Click OK.
Right-click on one of the selected layers, and Flatten Image.