100-400 II

[paulbrogden10]

Hello guys

I spent some time with this lens and I must admit their are issues with it. I was trying to focus on a bird as for getting closer maybe if I was in a hellicopter.  I am dispointed in this lens I was trying my best but what I found was the lens for no apparent reason would go out of focus at a very important point. even when I changed the settings from mode 2 3m  to infinity. And this was on a bright sunny day getting shutter speeds of 2000 by the way no converter was on my 7d.  I forgot to take them i was disapointed to be honest  .

I was photographying a bird slow moving a big bird I dont know what it was it was big and my focus would go out of focus right in the middle of a very important part and was gutted I also noticed the power drain on my battery was huge. As I said before manual focus some times is a must.

[cicopo]

Based on your description I'd say your battery is either old & weak or not properly charged. I can shoot roughly 1000 photos with any of my IS lenses during an event (per day) without killing a battery.

[Waddizzle]

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@cicopo wrote:

Based on your description I'd say your battery is either old & weak or not properly charged. I can shoot roughly 1000 photos with any of my IS lenses during an event (per day) without killing a battery.

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I agree.  You have already admitted that your battery isn't fresh, that it is few years old.

[ebiggs1]

I was on a school trip last week. Of course I am using a 1Ds Mk III but I shot all last week, some 2000 photos, on two batteries.  Neither was completely drained and neither was charged all week (actually 8 days) long.  The camera was never shut off but it was allowed to go to sleep after eight minutes.  Lots of chimping as the kids wanted to see themselves.

BTW, I never noticed my ef 100-400mm as a bigger battery drainer than any of the other lenses in that category.

[ScottyP]

There could be an issue with your copy, or with your other equipment, or it could be your technique, or even just your own unique perceptions and expectations.  

I have read hands-on reviews of the lens, however, and absolutely none of the expert reviews say the AF is bad, or that you should use this as a manual focus lens.  If that were the case it would be many many people, including amateurs on forums like this, enraged and spewing bile and blood through their tear ducts if this expensive telephoto sports lens was only good for manual focus.