I confess to being a Pentax fanboy. A couple of great things about Pentax are that any Pentax K-mount lens ever made will still fit on today's Pentax DSLRs and because Pentax has the image stabilization built into the body, it works perfectly with all that great old glass. It's amazing how well the wonderful fast primes from the 70's & 80's work on a modern DSLR body.