A lot of photographers sweat the decisions about what long lenses to purchase. Among Canon users a common decision is whether to get a high quality telephoto prime (plus one or more teleconverters) or to get a telephoto zoom. Perhaps the most common question is whether to get a 300mm L prime (f2.8 IS or f4 IS) or the 100-400mm f/4.5-5.6L IS USM.
Many seem to focus on the image quality (“IQ”) issue a lot when trying to figure this out. It is true that the primes have an edge on the basis of pure resolution compared to the zooms. At 300mm the prime will “beat” the zoom at the same focal length. But, as many have figured out, it isn’t quite as simple as determining which lens is “sharpest” – other factors can affect the answer to that question, and sharpness is not the only issue.
Continue reading Thoughts About Long Zooms and Primes and ‘Image Quality’
