Getting pin sharp birds? Frustrated!!

Guess the only way to find out is to try it.
Thanks for clearing that up.

Vulcan58 wrote in post #6664050
That contradicts Canons info - that the IS will be turned off when on a tripod as the circuitry in the lens foot detects the tripod, although power will still be supplied to the IS circuit.

One thing that gets me thinking - if the foot detects a tripod, how come the IS still works with the lens plate attached, using hand held?

Some of this information is probably forum folklore and not precisely what Canon says about IS -- at least my lens manual says when panning either hand held or on a tripod that mode 2 IS should be selected. If the tripod is locked down, then it doesn't really matter whether IS is on or off. The IS circuitry only uses significant power for a period of about two seconds after focusing or setting exposure with the * button or after a half press of the shutter. Otherwise, it is only consuming standby power.

AFAIK, there is no circuitry in the lens mounting foot -- I know that there isn't in my lens mounting foot.

Use One Shot, not AI ! I bet it cures your problem.

Get away from AI Focus.... useless in my opinion.

Sometimes the AF misses for some reason or other. If you manage to detect it on the viewer, try to unfocus manually a little and then refocus with the AF. It works for me with my 100-400 hand held.

I wouldn't use the one shot AF, in fact never have and I think I have a few sharp photos.

This Pine Siskin is from about the same distance (~25') as you were shooting at, but with the 100-400mm @ 400mm which also makes me think you are under-estimating your distance, at 500mm you are holding more glass and should be filling more of the frame than this shot did.

BradM wrote in post #6682481
I wouldn't use the one shot AF, in fact never have and I think I have a few sharp photos.

This Pine Siskin is from about the same distance (~25') as you were shooting at, but with the 100-400mm @ 400mm which also makes me think you are under-estimating your distance, at 500mm you are holding more glass and should be filling more of the frame than this shot did.

I use AI servo all the time for birds and wildlife, they move and are never static. Even at a feeder the bird is moving and at the distances for feeder type shots the dof even stopped down to f/8 or so is very thin, a turn of the head can take it oof.

If you are using the * button for focus it is simple thing to release the button and have it lock into place if the subject is staying still but it is so much easier to stay on the button and the subject to follow whatever move they might make.

Superb shot but are you sure this has not been cropped? I have a 400mm prime and there is no way I could fill the frame with a bird this small from 25' (and the prime is said to be longer than the 100-400 at 400)

Yes it has been cropped, leaving about 40% from the center of the frame.

Just forthe sake of discussion, which of the 3 focus range switches are you using? I have found that I need to experiment a bit at the kind of distance you are talking about to get the best AF. BTW my first long lens was the 100-400, I got some good shots with it but I never felt I mastered it, sold it bought the 400 5.6.

Maybe I'm underestimating your tripod (I don't have one) and your steadiness (I have slight tremor) but have you tried an off-camera shutter release? You could easily be getting lens tip from the shutter button, however soft you are on it.

I have that problem on a 100-400 f4L shooting from a beanbag mount on a landie, and not from a 70-300 shooting handheld!

Looks like your 500f4 and 30d combo is front focusing to me.
Esp the robin shot.
I suggest you try a focus test on one of those test sheets to check.
My 1dmk3 and 500f4 back focused whereas my 1dmk3 and 100-400 were spot on.