Hi, I'd like to get a lens for my D3100 (I already have a 18-55mm kit lens) that I can use for taking portraits with a blurred background as well as using it when I'm at kids sporting events and when I want to take landscapes. I don't like to have to change the lenses apart from having the load to carry.
Is it best to get a separate lens for different situations - maybe a 50mm and 70-200/300mm for sporting events and landscapes, or get one lens I can use in all situations?
What are the pros and cons of owning 2 more lenses versus a telephoto lens (70-200/300mm)? Which lens ( please include the specs) is cheaper, maybe lighter but not at the cost of quality? I just get so overwhelmed at the huge variety of lenses available, and I don't know which is best suitable for me.
I appreciate all advice as I'm fairly new to DSLR's and lenses.