Thanks for all the kind comments, actually I have found Perceptol diluted 1-1 in combination with the Delta 100 film produces extremely sharp negatives along with the lens. I have similiar results with the Rollei lenses as well as the Mamiya 6 50mm lens. I give credit to George Todd and his book "Elements of Black and White Photography" and he was kind enough to share some of his experience with this developer after an email I sent to him after reading the book.