grego wrote:
But Dave, IQ gain and loss is only relative to how and what the lens is being used for. Like you said, if you hand hold, 100-400 is the better choice. The IS will give you more slow shutter keeper shots than hand holding the Bigma. The 100-400 gives more mobility, but then anything over that really should be on tripod or monopod anyway.
And then there are many execellent 300's out there , like that Sigma 120-300 2.8. 
But Dave, IQ gain and loss is only relative to how and what the lens is being used for. Like you said, if you hand hold, 100-400 is the better choice. The IS will give you more slow shutter keeper shots than hand holding the Bigma. The 100-400 gives more mobility, but then anything over that really should be on tripod or monopod anyway.
And then there are many execellent 300's out there , like that Sigma 120-300 2.8. I thought that's pretty much what I said ... but better
Yes sir ... that 120-300 2.8 is a fine effort if the OP fancies carrying it around. Too short for me, and possibly too heavy, but for him it could be a great option to add to the list.
