Originally posted by Stavri The cream o fthe crop, top of the line, would be the FA* 200mm f4 Macro (or A* 200mm f4) which would set you back at least a couple of grand. The Sigma Ex 180mm f3.5 is the poor man's alternative of the FA* 200 f4. On the 90-105mm range the D-FA 100mm f2.8 WR is excellent. On the 25-90mm range the Sigma EX 70mm f2.8 is the top performer in term of absolute sharpness.
I wish
Pentax has two great macros the 35Ltd and the 100mm WR. The advantage of the Ltd is that it could easily be one of the best 35mm lenses. The 100mm is WR and is a good focal length for many of the subjects people like photographing in macro. The sigma 70mm is massive and unless you are really attracted to this focal length I think the two pentax lenses have much much better colour. The 70mm is very sharp, but I find I prefer the colours produced by my pentax lenses. I also have picked up an older copy of the sigma 50mm so I have a manual lens with a manual aperture. I find I am to close with the 50mm to use any kind of flash.
My 35Ltd is the most likely macro I will pack followed by my 100mm WR.
Bottom line is that probably any macro made in a pentax mount if not an excellent lens will be rather close to excellent. I think identifying your focal length, price you can affod and what you want out of the lens should be you guide rather than which is the best.