I am not really sure why modern photographers de-saturate a coloured photo to make it black and white. I am sure there must be some logic behind it, but I am not aware of it. I use my own logic. In nature and travel photography, those frames which has a lot of interesting patterns where the colour is not important, I turn them into black and white. In Wedding Photography, if I capture a frame where the emotion is more important than the colourful decor or the wonderful dresses or jewelry or make up I turn it into black and white. Here are some images from the travel and nature category.
This is a mobile photo, taken by a Nokia E71, shot at the Samode Palace, Rajasthan 
