http://www.nikonchat.com/nikon-vr-70-300mm/
What is good for an opening of a Nikon 300mm lens?
f4.5, 5.6 is good for taking pictures of birds, I take sharp pictures and clear, this is a good lens? nikon 70-300mm f4.5-5.6 VR lens
I do not know much about Nikon lenses, but it sounds like a good telephoto lens, so that the images should be nice and strong. A large aperture (04.05 A 6.5) will cause the bird in focus and background blur, and allow you to use a faster shutter speed, a narrow aperture is retained over the background in focus. I suggest using a large aperture, to keep focused on the bird.
Tamron 70-300mm for Nikon
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