Can we include non-Pentax but Pentax mount lenses?
The Tamron 90mm Macro gets my vote.
- Cheap (Between $200-$300 used)
- Sharp! (it's a macro, hard to screw these up). More importantly, it's sharp wide open, which increases its versatility (see below).
- Light (just a hair over 400g)
- Has an aperture ring (useful for extension tubes, etc. But also, makes it good with cheapo K-Q adapters. It makes an
amazing 500mm fast prime on a Q!)
- Excellent design (recessed front element) means no need for dealing with fussy lens hoods. In fact, I never put on its lens hood or cap when it goes in the bag.
- Focal length and performance makes it good as a portrait lens, or for event shooting (optimal situation is when you're facing towards a stage, like at a concert).
I used to just flip these because they kept popping up on my local Craigslist, but after using one for a while, its versatility made me want to keep one. I've used it for everything from macro shooting, to birding (with the Q), to portraits, and events.