I tried to take a photo that had a lot of elements to it. I was lucky that it was raining when I took the photo so it created some interesting highlights in the reflection of light on wet concrete. I mostly manipulated the whole image via the presets until I got a look I thought was compelling and then used that as a base to make some subtle modifications of the image using dodge and burns to de-emphasis other parts of the image so they did not draw your attention away from the centerpiece.
Alpha Channels make more sense in terms of Isolating the colored Pixels. I can see how it would be a more expedient and detailed oriented method of modifying the Pixel colors your targeting rather than using a method based on levels or curves. I would consider it a more surgical method. I would consider utilizing the TIFF file with the Alpha Channels a quick way to create some functional composite or layering effects in web development. You wouldn’t have to build a complex image or banner from scratch every time you wanted to create something new. You could potentially create a portfolio of Images Pre staged with Alpha Channels and manipulate them in your HTML editing platform of choice.
Again this guy pops up in the great tutorial videos. He did a really good job of explaining how to interpret what you are seeing in the RGB channel selection. The additional explanation of how the different channels convey information was great for anyone seeking additional understanding of the underlying concepts of the tools we are working within this class. I thought he did a great job highlighting the different ways of utilizing the selection process to create complex compositions on a more advanced level than what we did in our montage lesson.