Right now I am in the situation that I am about to purchase a 400mm f5.6L USM lens for my surfing, sports and birding shots.
The problem I have is that I have recently been offered a very good condition 300mm f4L IS USM lens for $400 less than what I will pay for the 400mm.
For most of the shots I will sit at 400mm so if I went for the 300mm then I would get the 1.4x TC with the change.
Would I be better suited getting the 400mm 5.6L or paying less for a VGC 300mm 4L IS, and spending the change on a 1.4x TC?
The issue that is bugging me a bit is that with the 300m I can have 300mm f4 and 420mm f5.6. I don't want to skimp out on IQ, which is why I like the 400mm because it is a natural 400mm and offers superb results.
I hope that I have not been too muddled with my thoughts above
Your thoughts on my dilemma would be greatly appreciated because I am looking to make a purchase within a day.