In the category of "yes you can", here is a shot I was completely unprepared for but got it anyway.Walking down a very densely overgrown trail to get to a spot where I was going to shoot white-tailed kites, I came upon this old boy. I had the 1.4x TC on the 400 and could not get any farther away from the owl. While I held my breath and took off the TC, this guy just sat there waiting... I dialed up the ISO, down the SS, and flipped up the flash on the camera. This is full-frame. I figured I wasn't going to get anything good at 1/125 hand-holding that lens (no IS), but when I got home I had a nice series. I like this one the best because he was getting bored with me and gave me "that look".
50D, 400mm f/5.6
Manual mode, f/5.6@1/125, ISO 800 WB 5100K
AI Servo autofocus, HH, on-camera flash at FEC -1 2/3







Walking down a very densely overgrown trail to get to a spot where I was going to shoot white-tailed kites, I came upon this old boy. I had the 1.4x TC on the 400 and could not get any farther away from the owl. While I held my breath and took off the TC, this guy just sat there waiting... I dialed up the ISO, down the SS, and flipped up the flash on the camera. This is full-frame. I figured I wasn't going to get anything good at 1/125 hand-holding that lens (no IS), but when I got home I had a nice series. I like this one the best because he was getting bored with me and gave me "that look". 

I even got the TC into the little draw-string bag without dropping it on the ground. 
