> The problem can be right selection of model. From what I've read here > and there, the best ones are Tokina and Sigma (still manufactured)
I prefer the Tamron SD 500/8 to both the Sigma and Tokina. (Still have the former, no longer have either of the latter.) > Mirror lenses generally have lower contrast than classic ones Agreed. > (but it should be easy to correct in case of digital) Yes and no. You can modify contrast after the shot, but you can't later get back any subtleties already lost due to lack of contrast. > but they are free from chromatic aberrations. Yes and no. Yes, if the lens has no refractive elements. Not quite true in the case of those that do. Fred
