Thomas photo quality attracted my attention and hence I asked the question. I am not very sure what I should do if I would like to upgrade my gear.
Canon 800 mm spec as per attached link.
http://www.canon.com.hk/en/Consu ... 47&tag_id=12287
It weights 4.5 KG and it is indeed not cheap. Of course, there were also plenty high quality photos posted recently.
Some birders are using 500mm plus an extension lens to achieve approx 800mm. Perhaps we need some good advices on differnt set ups in related to their autofocus ability. With such distance, is autofocus effectively? I may ask another stupid question.
Thanks in advance for more information,
tsa