To all 100-400 users?

Here is a question. Do you notice a difference / problems focussing between 100mm and 400mm and on which body if you do? I ask because I took my lens in for checking, we have a Canon reapair place in Munich, and they rang me back next day to ask what i thought was wrong....since they could find nothing at all. When I picked it up they explained all modes were tested at various zoom lengths...nothing up at all.

It was tested with a 1Ds body, she wasn't which MK it was. I know plenty of people have said the 1-4 is a different lens on the 1D bodies due to the faster stronger focussing...so I wonder if the lens is fine but Canons lower bodies are just plain sh*t?

My first test was in AF Focus mode, at 100, 200 and 300mm the camera re-focussed as I panned around the room...but at 400mm it refused to so. In servo mode it re-focusses but seems to struggle when I hold still, often not quite locking on. It is frustrating as hell as I wanted to buy a second body, cropped (maybe 40D) but if the 1-4 performs like this on all but 1D bodies what is the point?

mine works fine on my XT and 40D

No issues with mine on multiple bodies - 20D, 40D, 5D, 1DMKIIN.

OK, cheers guys. I guess something somewhere is up....hope it is not the camera.

Mine focusses like a champ on both my XTi and my 40D, exceptionally well on the 40D even indoors.

Focus on my 40D is pretty darn fast and accurate.

i've used the lens on 30d, 5d and 1d3. no problems.

ed rader

Thanks guys for the replies.

I've used the lens on a 350D, two 400Ds and a 40D. No problems. 400D and 40D worked better with AF, faster and more accurate.

Kind regards, Wim

Ditto the abobe...10D, 30D and 5D just fine.

Neilyb wrote in post #4748690
My first test was in AF Focus mode, at 100, 200 and 300mm the camera re-focussed as I panned around the room...but at 400mm it refused to so.

Remember, at 400mm, you are at f/5.6 - you're going to need more light than you do at 100/200/300. Go outside, and try it - not inside.

Neilyb wrote in post #4748690
In servo mode it re-focusses but seems to struggle when I hold still, often not quite locking on. It is frustrating as hell as I wanted to buy a second body, cropped (maybe 40D) but if the 1-4 performs like this on all but 1D bodies what is the point?

Seems to confirm even further that you are "on the edge" with available light. Try it outside with good light.

I've used mine on a 350D, with no problems. But it is "light hungry".

tundrwd wrote in post #4757268
Remember, at 400mm, you are at f/5.6 - you're going to need more light than you do at 100/200/300. Go outside, and try it - not inside.

Seems to confirm even further that you are "on the edge" with available light. Try it outside with good light.

I've used mine on a 350D, with no problems. But it is "light hungry".

Also, is the closest wall to focus on more than 1.8m (or 6.5m) away? Just a thought.

Mine worked fine on the 30D, 40D, and 5D.
The only thing that messed me up was to remember the 1.6x CF and how that affects the shutter speed formula.

Always would screw things up switching from the 5D to 30D for instance...

My focuses fast on a 30D.