AlanF said:
I have decided against uploading any comparisons. The photos on his flickr site at 600mm f/8 - f/11 really are very good. At f/6.3 some are a bit soft. If I didn't have the 300mm f/2.8 II I would definitely buy the Tamron. For what I photograph and the distances involved I use 600mm 99.9% of the time and never zoom out. If I was going on safari I'd be tempted to take the Tamron. I think the lens is remarkable value for the price and has very acceptable quality.
Alan, I think comparisons would be tough and given all the variables in outdoor testing and post-processing, it's hard to evaluate unless the comparisons are done side-by-side, as you've done in other posts.
Also, I'm in the same boat with my 300 2.8 IS II & extenders. I really wish this lens would have been about 5 years ago when I started getting into wildlife photography, but I've always used primes beyond 200mm and I don't find them all that limiting. I can only think of a handful of times I wish I could have been able to zoom in or out because I couldn't get closer or further away from my subject.
For those without a 100-400, 300 4, 400 5.6, or the "big guns" in their kit already (like Justin), this lens is an awesome value I wouldn't hesitate for a moment to buy it.
The first I had seen, and I had thought maybe there were too many variables at work in such a quickly shot test. So I thought I had better wait for something a bit more rigorous and controlled. (tripod mounted, VC off, ... see what the lenses were capable of at their best) I, like some of his commenters, was surprised at the results. And compared to the posted pics in Dustin's report, I was skeptical of the difference in the camahoy posting. Maybe his 400mm lens was a bit off as some asked?
