I recently learned about the 1.5x factor on DX cameras like the 5100. I read many reviews before ordering my D5100 and found that I wanted a 50mm f/1.8g lens. Shortly thereafter I found that this will essentially be a 75mm lens for us and I won't have much for options in close quarters or indoors. I didn't want the 35mm but may get one since it is about a 52.5mm for us.
My question isn't about which is better because that is everywhere and I will experiment to find what works for me. My question is which lenses does the 1.5x factor apply to and how can I tell? I will keep the kit lens (18-55mm) and 50mm until I learn the ropes and get to know the camera and my style first. Then I will want to upgrade that kit lens to something better and possibly pick up that 35mm if the 50mm is too close up indoors.
Can someone break down this DX 1.5x factor and when and when not to apply this to lens purchases? Thanks!