Yes, I have the 18, 24, and 50mm Pentax 110 set (one's missing a rear lens cap. Anyone have one to sell me?). I bought these for my Pentax Q which, again, has been a disappointment (if you don't want to buy Q-mount lenses don't buy a Q!). So, they're all f2.8. I've seen some interesting shots taken in the archives from the 18. I don't know about the others. Do you guys like yours?