A:Answer The “contemporary” lens you are referring to is the Sigma 150-600mm lens selling for $989.99. Best Buy offers the following lenses in this class:
1. Tamron 150-600mm (first generation) $949.00
2. Tamron 160-600mm G2 $1299.99
3. Sigma 150-600mm Contemporary $989.99
4. Sigma 150-600mm Sport $1799.99
According to reviews, the quality of lenses are as follows:
1. Sigma Sport (best)
2. Tamron G2
3. Sigma Contemporary
4. Tamron (1st generation)
Items 1 and 2 are more weatherproof than the others. There are good reviews on Item 3 but lacks the weatherproofing. Item 2 is a an improvement from the initial development of Item 1 and has more features since it came out a couple years later.
You should read the reviews and comparisons of these lenses before you make a choice, and definitely confirm the lens you select will properly focus and operate with your NIKON D7100. Not all so-called dedicated Nikon mounted lenses from 3rd party manufacturers will operate properly.
So far, I am more than satisfied with the performance and results of my TAMRON 150-600 G2 lens.