I have an old style Nikon 300mm f/4 that, unknown to me, I somehow damaged. I learned of the damage when a single drop of rain fell off my car and somehow penetrated past the objective lens and the inside fogged up. I sent it to Melville and they quoted me a repair price that seemed reasonable (approx. $250.00) but I've been on "parts hold" for 4 weeks. I have a vacation coming up and rather than risk not having the 300mm, I'm renting Canon gear (EOS 7D, 300 f/4 L, IS and extender 1.4x III). (jr)