Without [good] light, photos would be very boring overall. What do I mean by "good" light? There are the universally accepted concepts of the golden hours at dusk & dawn. And then there are other possibilities, depending on the individual situation. Depending on your subject, your idea of good light may be different than another's.
The golden hours around sunrise & sunset really do provide some magical light. Shadows & warm colors abound. When you get the alpenglow colors, the whole feel of the photo changes. These wonderful changes occur because the angle of the sun differs then versus at midday when the angle is almost directly above and there are no nice shadows.
The above photos illustrate the changing (and less-desirable) light that occurs in the morning at 8am versus later in the day at 1230pm. All the shadows that give Dune 45 in the Namib Naukluft Park in Namibia its characteristic profile are gone by midday. It's still a nice photo, but see what you miss if you don't shoot around sunrise or sunset!!
Depending on what you want to convey with your photos, the light is everything. If it's cloudy, does that mean you can't shoot? Of course not, but you need to assess how you're going to shoot to make the most of the [grey] light you do have. With clouds, there are no harsh shadows or glare, so sometimes you can get very nice colors without dealing with difficult shadows or contrast.
Sometimes you don't have a choice of when to shoot because you're on a tour with a schedule that you must follow. Learn to make the best of the situation and figure out how to get the best shot you can with the available light.
© 2012 fatCATfoto by Christine Nimitz