In this video, I demonstrate how to use Trey Ratcliff's HDR photography methods in Aperture and Pixelmator using layer masks and digital blending.
The photo I use to demonstrate is "Break Between Storms", which I published a few days ago.
I blended the foreground, Lighthouse and tree into the dramatic sky that Photomatix gave me. I then applied a Gaussian blur and darkened the sky with an overlay layer setting. Then I sought to add some light streaks from between the clouds and sun with a zoom blur and blended that in.
I couldn't quite duplicate the second photo I screencasted but the gist of the technique is still there.
I bought Aperture for Mac when it was nearly half the price of Adobe Lightroom. Since then, Lightroom has dropped in price to ~$120USD, $40USD more than Aperture and much more robust for editing. Specifically, I have found the noise reduction in Lightroom is far superior to Aperture in addition to all the many tools included such as radial and gradient filters to name a few features.
Photomatix by HDRSoft: http://www.hdrsoft.com/
Pixelmator for Mac $30USD: http://bit.ly/NEw623