chrysoberyl said:
Lenstip has reviewed the Sigma 150-600 S.
Be aware that they received the lens they tested from Sigma. To me, receiving a test lens from the lens manufacturer means that:
1. The lens has probably already been tested by the manufacturer, and selected as being one that is the best possible.
2. You will never be able to get one as good as the one tested thru a store.
3. Its also implied that a poor review means no more free lenses to test, so there is pressure applied to go easy on any flaws. Even DXO does not take manufacturer supplied equipment, but purchases or rents the test items, and usually they test multiple items.
Those may or may not be true, but should be considered when reading the review. Independent review sites do not take freebies from the manufacturer of the product that they are reviewing. Its like a Automobile Magazine that not only gets a car to test, but depends on advertising.