About 10 years ago, Tamron released a 150-600mm f/5-6.3 lens that became wildly popular for offering photographers decent image quality paired with extreme focal lengths, a combination that used to be prohibitively expensive most of the time. Since then, we have seen an explosion of similar lenses, making genres like bird photography far more accessible than they used to be. One such lens is the Sigma 150-600mm f/5-6.3 DG DN OS, and this excellent video review takes a look at the sort of performance and image quality you can expect from it in usage.