Darken skies

I am currently reading Tom Ang’s “Digital Photographer’s Handbook”. I have to admit, although he is giving a lot of useful information and showing interesting techniques, sometimes the book is hard to follow, it is not step by step, requires a lot of prior knowledge, and the information need to be extracted from text as well as example pictures combined. That said, it still inspires. I just went to look for a photo with green or red elements, and blue sky (hm, I didn’t know I have so much overexposed skies on my photos) to try Channel Mixer to make black and white picture with black sky. It is somehow like “amateur’s of infrared” photos (meaning made with software rather then special lens).