My girlfriend has a Vivitar 19/3.5 (for yashica, but I think it is also available for pentax K). I'm not able to tell if it is a good lens or not, but from what I saw it seems to ship contrasty (?) pics and is also well flare-resistant (even with the sun in the pic flare are few). Oh, I paid for it 100 euros (used, of course)... I understand the original poster was looking for a wider lens than a 24, rigth?
hope this can help, Danilo.
