Canon 400 mm f 2.8 MKII

[Jesse11]

Finally got one and and my first impressions are:

1. It is definitively hand holdable; at least for 1.5 hours for me; incredibly light and well balanced.

2. Shows vignetting wide open when used with a 7D, but due Adobe CS5 lens correcting software makes this not an issue.

3. Extremely quiet compared to my 300 IS. It behaves a lot different from the 300.
Although both lenses are 2.8, the 400 subjectively seems to gather more light.

4. Autofocus seem confused when tracking birds in fligth, it freezes and goes to infinity; have to refocus in a close object and starts working again. Hope a software glich the will be corrected.

5. Other than the reduction in weight, the other physical improvement is the lens attachment groove; installing and removing the is extremely easier compared to previous models.

6. The major drawback is cost but justified its purchase in that these long lenses are a way to protect $ from inflation. I bought my 300 in 2008 for $3500 and now sales for $4000 to $5000.

Will post a detailed review when I get more experience with it