Pentax smc D FA MACRO 100mm F2.8 WR This lens is designed to perform nicely on portrait or Macro photography. Its specific design specifications mark it as weather-proof.To check its image quality measurements on the Pentax K5 and the K20D click the following links:Pentax smc D FA MACRO 100mm F2.8 WR mounted on Pentax K5Pentax smc D FA MACRO 100mm F2.8 WR mounted on Pentax K20DThe review, however will be based on the better resolved sensor, currently embedded on the Pentax K5The DxOMark ScoreTo have a scope on where this lens stands, at DxOMark we have previously