Canon 100-400 f4-5.6L IS USM Lens

[kcrook]

Re: Canon 100-400 f4-5.6L IS USM Lens

Hi - so here are a couple of examples. Firstly 'stick'. This was stuck in a lake about 20 ft in front of a bird hide at a local wildlife reserve. Selecting centre point I focussed on the very tip of it as you can see so as to be ready when a bird landed. The tip is not in focus but an area lower down is. I focussed with no tripod but the lens was supported on the edge of a bird hide. It was taken at 3200ths ISO400 f5.6. I took several stick shots and did not manage to get a single sharp one.
Duck 1 and Duck 2 were taken split seconds apart 1200ths ISO200 f5.6 with AI servo. The first is sharp - in the second the focus has moved off the duck and picked up the background even though the duck did not move.
There a plenty of other examples where I have centre point focussed bang on the target but its not sharp.
I too have the odd shot that is tack sharp, fantastic, but it seems to be a random event.

[Woolley]

Re: Canon 100-400 f4-5.6L IS USM Lens

with AI servo.

Seems to be the standout phrase in your post. I wouldn't be using that for still subjects.

In your duck shot I'd suggest movement of the lens has shifted the point off the duck, the lens is refocusing and you've taken the picture before it's changed back. You haven't got to wobble much at 400mm for the focus point to wander off the duck and back. Try single shot AF and see if that helps?

[mikep]

Re: Canon 100-400 f4-5.6L IS USM Lens

I agree with Woolley's comments above. Also for still subjects, try using AF and single shot, take your first shot to get the focus where you want it, then check the screen to see it's ok. If it's good, select MF and the focus won't change for the next shots!

Alternatively, a more advanced technique would be to set up the buttons using the custom settings to use back button focus, then you keep the focus and exposure separate. Focus using the back button you've assigned for focusing, and take your shots using the 'shutter' button, with each press of the shutter button setting the exposure at that time.

Hope that helps! Mike

[kcrook]

Re: Canon 100-400 f4-5.6L IS USM Lens

Thanks to all for your comments. I get the point about AI servo though that does not explain stick misfocus when I was on single shot. Will give the back button a try - what a shame I can't allocate AI servo to the back button so I could easily kick it in when a stationary bird takes off!

[MX5]

Re: Canon 100-400 f4-5.6L IS USM Lens

Thanks to all for your comments. I get the point about AI servo though that does not explain stick misfocus when I was on single shot. Will give the back button a try - what a shame I can't allocate AI servo to the back button so I could easily kick it in when a stationary bird takes off!

If you've got C1/C2/C3 on your DSLR ... you can set C1 for BIF and C2 for birds what are still for example. [Setting appropriate parameters for each]. I can re-programme the DoF preview button on my 7D although I've never done that.

[Muscat]

Re: Canon 100-400 f4-5.6L IS USM Lens

I may have missed it but have you tried to micro adjust the new lens to truly match it to your camera? I have the same lens and found that I had to adjust the focus of the lens to work properly with my camera. If you still have problems then you could send the lens and camera to Canon who can match the focus of the lens to your camera

[Oggie]

Re: Canon 100-400 f4-5.6L IS USM Lens

I agree with the others about single shot focus.

I would also try to avoid F5.6. Mine comes to life at about F8.