I have used Nikon S610 till now..and I do almost a fair job with it..now I want to advance to DSLRs. My budget would be around Indian Rs.50,000 - 60,000(1000$-1200$). My options seem to be Canon EOS550D, Canon EOS600D, Nikon D5100, Nikon D90. I want to practice manual focus. Kindly provide tips for effective photography too.KINDLY SUGGEST. Thank You.