Tack sharp to soft as a wet noodle, lens or operator error?

JJD.Photography wrote in post #15915732
Whenever I am shooting (birds - most of the time perched) my keeper rate is pretty low. The images are either tack sharp or not. Even during a series of say 10 shots of the same bird in the same spot I may get several keepers or I may end up deleting them all due to not being sharp.

me too..
I am taking the practice practice practice approach. In my case I can usually track back the problem to operator error..
But.
'm getting better, I'm sure you will as well,
The cardinal shot is awesome, which would indicate it's probably not the equipment

I agree with the 'small birds are jittery' comments. I too have experienced the sharp shot at 1/30s only to have soft images at 1/250s.

I was just a the zoo today trying to get a shot of a small bird and used between 1/125s and 1/15 with a monopod and my 70-200 f4IS +1.4x (they were pretty close).

The sharpest shot was at 1/15s. The bird was still for that fraction of a second. I think it was just moving slightly on the other shots.

The F stops here wrote in post #15920342
I'd say my keeper rate is in the 30-40% range as well, i've found shooting in Av with spot metering and center point focus and AI servo to be the most beneficial of all the settings i've tried, i mess around with the ISO a lot to keep my shutter speed up, i also found shooting is burst mode has helped yield more keepers (3 shot burst i usually get 1 out of 3 spot on)

IMAGE LINK: http://www.flickr.com/​photos/lenzfreak/87157​46192/
Bird23 by LenzFreak, on Flickr

I've found patience and experimentation to be my best friend

These are the techniques I use as well. Especially the 2-3 frame burst. Before I learned that I would be searching dozens of photos looking for keepers. After practicing that for a good while, I now search dozens of keepers looking for that special pose like the following...