Transitioning from the newer 645 series to the TLR I'm guessing you are actually seeing comparative loss of contrast as opposed to lack of sharpness. The TLRs MUST be shot with lens hoods as they are more subject to flare than the newer super multi coated lenses you are used to. Also try changing films. I was also very disappointed with my first C220 for the same reasons but I figured out that changing to higher contrast films and/ortechniques helped. For instance, in B&W develop 5-10% longer to boost contrast. For color print, fill flash makes a world of difference. For transparency, just shoot it - the chromes are the only photos from the TLR I was ever totally happy with.