fuzzy canon lens: EF 100-400 L IS

Davy Crockett · #1 (**permalink**) 24-06-2011, 05:09 PM

The lens can take some good pics with good light and close range, but say bird shots in flight, the auto focus won't lock on to the target and be sharp.
Any Ideas please.

nigel_b · #2 (**permalink**) 24-06-2011, 05:23 PM

I'm not a Canon person but I suspect the first question will be what body is it hung on?

Lancashire Lad · #3 (**permalink**) 24-06-2011, 05:24 PM

Hi david,

Bird photography isn't my thing, but I'd be tempted to think that the problem may be more likely to lie with the camera's selected "point settings" for the autofocus system.

You may find that changing to a different set of autofocus points solves the problem.

Regards,
Mike.

glsammy · #4 (**permalink**) 24-06-2011, 05:45 PM

Tell us the camera! Makes a lot of difference to the available options.

johnf3f · #5 (**permalink**) 24-06-2011, 11:42 PM

Switch your camera to center point AF and AI servo - then turn the IS (on the lens) off - this should give you a better "Hit Rate" and speed up AF a little. After that it's lots and lots of practice! Also try playing around with the exposure compensation a little (helps with birds against a bright sky).

Davy Crockett · #6 (**permalink**) 25-06-2011, 08:04 AM

Hi Nigel, Mike, Graham, John.
Thanks for your comments; the cameras i use with it are Canon 40D & Canon 600D.
I experience the same results from both! i have been experimenting with the lens for nearly a year now, have tried all metering modes on the cameras without success

Davy Crockett · #7 (**permalink**) 26-06-2011, 03:12 PM

Hi again, i assume the silence is that you’re as puzzled as i am.

colincurry · #8 (**permalink**) 26-06-2011, 06:16 PM

Have you tried your lens on a friend's camera; or do you have a friend with a 100-400 to try on your camera?

Do have a look at Custom Function III-1 on the 40D and make sure Focus search is switched on (page 157 of the manual). This had been switched off on my 7D and caused a lot of angst and ages to diagnose.

I use a 100-400 and it is very good.

The other option would be to have your cameras and lens calibrated by Canon but that would cost unless any of your kit is under guarantee or insured.

Good luck

Colin

nigel_b · #9 (**permalink**) 28-06-2011, 10:18 AM

Quote:

Originally Posted by Davy Crockett

Hi Nigel, Mike, Graham, John.
Thanks for your comments; the cameras i use with it are Canon 40D & Canon 600D.
I experience the same results from both! i have been experimenting with the lens for nearly a year now, have tried all metering modes on the cameras without success

It's not the metering mode that was suggested could be wrong. Personally I can only do BIF in manual exposure and I muck about on the day to get the settings right for the prevailing conditions.

It was the focus mode that was suggested you take a look at.

Davy Crockett · #10 (**permalink**) 29-06-2011, 11:45 AM

Quote:

Originally Posted by colincurry

Have you tried your lens on a friend's camera; or do you have a friend with a 100-400 to try on your camera?

Do have a look at Custom Function III-1 on the 40D and make sure Focus search is switched on (page 157 of the manual). This had been switched off on my 7D and caused a lot of angst and ages to diagnose.

I use a 100-400 and it is very good.

The other option would be to have your cameras and lens calibrated by Canon but that would cost unless any of your kit is under guarantee or insured.

Good luck

Colin

thanks for the message Colin, will investagate