Yes you are right, it is time-consuming. And every time I want to compose photos using natural light, I always have to close the doors and windows so as not to admit any air movement- or the subject will sway. Even a slight movement will cause a blurry picture. And it's even worse when I use both natural light and flash in conjunction (this provides really crisp photos without the harsh shadows): as the shutter speed is set to very slow levels, I even have to hold my breath while the 10 second timer is ticking!