Comments about Sigma 28mm F1.8 EX DG Aspherical MACRO Lens for Pentax-AF Camera:
Great lens for the money. Use it indoors with my 50mm (F1.4), mainly at F2 to F2.8 w/ no flash. Pictures are just surprising. Shooting moving subjects at F1.8 indoors will result in blurry / not focused results as expected with the very thin DOF. F1.8 will require some PP to improve sharpness but results are useable.