I received my new 100-400mmL ISlens today, the 2 stop IS is a big step down from my 70-200mm F/4 L. I can stack TC's on it and get totally stabilized images that are sharper than my 100-400mm IS at 400mm. My 100mmL is yet another step up in IS efficency.


I have been hampered by rain and snow as well, so I only had a hour or two before bad weather hit us.


The lens is really nice, and the IS does work, but I got a few blurry images at relatively fast shutter speeds that never would have happened with my newer technology lenses.





I'll be testing some more, but, if I can just put a 2x TC on my 100-200mm F/4 L IS and get sharper images, the 100-400mm goes back.


I picked up a very nice 600mm f/4 L non is yesterday locally, so I am anxious to try it as well. The first few shots came out well with no TC, but with TC's, I struggled to get sharp images. I haven't yet used a remote shutter release or mirror lockup, I'm waiting for good enough weather to spend some time learninng both.