http://www.nikonchat.com/50mm-1-4g-nikkor/

Need help with my Nikon D90?
So I have a Nikon D90 with an 18-105mm lens and I am planning on upgrading it for this upcoming holiday Christmas my choice is to either get a SB-900 flash or Nikkor/nikon 50mm f/1.4G AF-S. Which would you prefer to get out of those two to make a better quality photo? Thanks. I want to have a family frame up in my family room so please help.
If you have a white or nearly white ceiling, I think you will get a better photo using your 18-105mm and the SB-900 than with the 50mm f1.4 and available light.
Carl Zeiss Planar T* 50mm f/1.4 Hands-on Review