I'm going to rent the 70-300 L this weekend along with a 1.5 Kenko extender.


My current gear is 60D with 18-135 IS and 55-250 IS lenses. This will be the first experience I've had with high performance lens ring type USM auto focus. I'm relatively happy with the 18-135 shooting f/8 landscapes, but have had hit or miss luck with the 55-250 for sports & limited wild life usage.


My plan for the weeknd is to go to a local race track for pics, stop by the state park for general wild life and possibly hawks or great blue herons and then a local park (for whatever I can find) to try and see what the lens can do and get a feel for how much better the "L" lenses are than the 55-250.


Here are previous examples from the race track:


first -- a near miss @ 100% then the resized shot


second -- a 55-250 shot that worked out @ 100% then the resized shot


[img]/resized-image.ashx/__size/1000x0/__key/CommunityServer-Discussions-Components-Files/8/2678.100-Percent.jpg[/img][img]/resized-image.ashx/__size/1000x0/__key/CommunityServer-Discussions-Components-Files/8/6332.2011_5F00_07_5F00_31_5F00_1736.JPG[/img]





[img]/resized-image.ashx/__size/1000x0/__key/CommunityServer-Discussions-Components-Files/8/8741.2nd-100-percent.jpg[/img]


[img]/resized-image.ashx/__size/1000x0/__key/CommunityServer-Discussions-Components-Files/8/8130.2011_5F00_07_5F00_31_5F00_1739.JPG[/img]


My main reason for bringing the extender is just to see what it is capable of. I know the 70-300 f/4-f/5.6 will effectively become a 105-450 f/5.6 - f/8 and autofocus may not work. It's getting dark in Illinois early now so my window of opportunity to try this out is mostly Saturday and Sunday and I want to get as much out of it as possible.


If you have any suggestions for how to effectively evaluate this particular lens, as well as how to evaluate overall image sharpness and autofocus performance of the "L" series of lenses, I'd be happy to take any suggestions.


Best Regards


Dave