I have had a 75-300 mm f4-5.6 III USM for a little over 10 years now and have used it with myfilm SLR. It has produced some of my favorite pictures. In June, I made the jump to dSLR and bought a 7D. In doing so,I found this website. Turns out neither of my original lenses are all that well regarded. To upgrade my lenses, I bought an EFS 15-85 f:3.5-5.6 IS USM lens and have set aside the $1,200 to $1,600 to upgrade the 75-300 mm range with either the 70-200 Lf4, the new 70-300 L, or the 100-400 L.


I know this question is a little dumb on the surface, asthe reviews, MTF charts, etc all show that the "L" lenes are significantly better both optically and in build quality. But I am wondering specifically how they are better, or, how the below images would be improved with one of the "L" lenses?


I took these photos yesterday at North Hampton Beach, NH after Tropical Storm Earl moved past with my current75-300 mm lens on my 7D.I can see some purple fringing, the sea behind the surfers looks odd, and there seems to be a haze/fuzz around bright objects. But that is looking at 100% crops. Are those the areas where the new lenses will be better or are there others? Will they also be sharper?


Thanks,


Brant[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.64/Surf-1-100_2500_.JPG[/img]


100% crop above...full picture below. 300 mm, 1/800th, f5.6


[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.64/Surf-1.JPG[/img]





[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.64/Surf-2-100_2500_.JPG[/img]


100% crop above, photo below. 300 mm, 1/640, f/8.0


[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.64/Surf-2.JPG[/img]





[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.64/Surf-3-100_2500_.JPG[/img]


300 mm, 1/800th, f/5.6


[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.46.64/Surf-3.JPG[/img]