Ira,
I was actually in Florida! Orlando and drove north to Virginia. I have lots of shots at Disney that have this problem, but it was definitely not fogging. It was 95 and no clouds which I am not used to. If it gets 95 here they declare a state of emergency
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Gerry,
I think you are correct. I have shots taken with the DAL 55-300mm at roughly the same place & time and they do not show this effect. I am wondering if the 77mm front element (and the FF lens design) is what is causing it. I'll test with a lens hood and see if that helps. If I can find one for this lens.....