macro lens

I love my new K5 but would like a macro lens for it. I see pentax do a 100mm macro which to me is too long (as I would like this to double as a prtrait lens) does anyone have any recomendations for a macro lens at about 50mm?
thanks
Richard

What are you planning to use it for ? For insects etc. the longer the macro lense the better ... longer working distance. When you get to 35/50 macros you have very limited working distances.

Pentax DA 35mm macro
Pentax D-FA 50mm macro
Sigma 70mm macro

All superb lenses.

Good comment about the 100mm being a bit long for a portrait lens. The Sigma 70mm might work, and would be a good compromise as well as having amazing IQ (as most macro lenses have). I've got the Tamron 90mm which is great, it works for candid portraits but I tend to prefer my DA35 or A50mm for more intimate close up portraits and full body shots. 35mm is often said to exaggerate people's features a bit too much but I don't mind the effect. And even with a 90mm lens i'm too clumsy to photograph nervous insects so the 35mm macro appeals as a lens which can take into flower buds and down among clumps of toadstools etc.

As Mike-P said the Sigma 70mm macro is an excellent lens. Recommended.