Opteka 420-800mm (2x Teleconverter Converts Lens to 420-1600mm Super Telephoto) f/8.3 HD Telephoto Zoom Lens for Nikon D4s, D4, D3x, Df, D810, D800, D750, D610, D600, D7100, D7000, D5500, D5300, D5200, D5100, D3300, D3200 and D3100 Digital SLR Cameras
"Great zoom lens for the price"
I was really impressed with these, after reading mixed reviews I worried for the price but I have been able to get some amazing shots of the moon and the zoom goes a long distance. I've uploaded a photo of the moon I took using it. The only downfall is dust gets in there after a few uses and with the lens being so long they are hard to clean, but so much cheaper that auto lens, although do expect to be taking many shots that you will most likely delete as for the manual zoom, I personally find that the fun 😬