Tuesday, January 22, 2013

DSLR Camera Lens Help? (NIKON)?

I am using Nikon D3100 with Lens 18-55mm VR. I want to buy a new lens I was thinking to go for 70-300mm VR.
Would it be a good decision or I should go for some other lens?
And what are sigma lenses?
Are they worth buying? Do they effect the image quality, focus, zoom etc as compared to the original lenses?
>>> DSLR Camera Lens Help? (NIKON)?