Originally posted by boriscleto Focal was the store brand for K-Mart.
...and the quality level is typical for off-brand/house-brand lenses of the time (late 1970s through 1980s). If you get one for free or cheap, give it a try, though I don't know that I would spend over $15 USD for any Focal lens, prime or zoom.
Addendum: Conflating Focal as a brand with established third-party offering such as Tamron, Vivitar, Kiron, Sigma, Tokina, or even Soligor from the same era is a mistake. That does not mean they categorically suck, only that performance reflects the original price point.
Steve