Hi, I just purchased a used 100-400 (having had lusted after it for years!). When i took it out today and put it on my 7d and turned it on the lens is like twitching in side...when i look thru the viewfinder the displlay jumps and the lens wont function. You can actually look in the end of the lens and see it jumping... Sometimes it works fine, but more often than not when i turn the power on the lens does this flicking thing...any ideas? I trued takeing the IS off...switching it to manual focus, doesent seem to matter
Matt Willison wrote:
My Father tried it out when it was purchased....and for the first few minutes on my 7d it worked good...even with the IS off it clicks and jumps
Yes, if there's a short it could be getting sporadic activation even with the switch in the off position. I'd be worried about it possibly damaging the camera, as well.
If you can't return it, then you'll have to send it in for repair, because I can't think of anything easily repairable by the average person that could cause what you're decribing.
Hopefully the cost of repair plus the price you originally paid will still be less than what a new one would have cost.
Does it do that in manual focus? You're not trying to focus on something inside the minimum focus distance, right? That lens needs a lot of light and contrast to focus. Take it out on a sunny day and try focusing on a distant object with high contrast.
Richard Nye wrote:
Does it do that in manual focus? You're not trying to focus on something inside the minimum focus distance, right? That lens needs a lot of light and contrast to focus. Take it out on a sunny day and try focusing on a distant object with high contrast.
Since the OP mentioned the image "jumping" I didn't even think about focus, but yeah, it could be the AF sytem, too.
Since it does it even when switched to manual focus, though, I don't think it's just a low light problem.
I had this same issue with my 100-400 lens last summer and had to send the lens into Canon. I just pulled my repair ticket on this and this is what they fixed:
IS assembly was loose and the camera shake prevention feature did not function. The IS assembly was reworked.
I haven't had any issues with it since. I can't tell you what these repairs cost as the work was done under the warranty.
i am unsure about a monopod or tripod...it does it in af or mf mode. I was outside during mid-day yesterday and changed every setting i could think of....
Oh, another one. This is what I wrote in the other thread:
"Yes, mine had the same problem, it would jump pretty violently from side to side and wouldn't focus. It even jumped with the IS being turned off. CPS eventually replaced the IS and the IS switch. It's been perfect since then. It was within warranty, so I can't say how much this would cost."
...in terms of what I've seen as normal for the 100-400, my six year old UU would swim around a bit then arrive at a stable image. My new UZ appears to go directly to a stable image without the swimming around dance. Neither have jumped or shown symptoms described by the OP.
The swimming around bit seems to concern a lot of new 100-400 users, so the subject comes up pretty often.
I had the same problem with mine last year. Started up halfway through my Galapagos trip. Image would jump and I could see an obvious IS element moving inside when I tilted the lens back and forth. Once the IS locked, the images were fine but locking could take up to 10seconds. Canon Canada replaced the IS assembly out of warranty for $530CDN. Also my Av value would flash between 00 and the set value at the exact same rhythm as the jumping element.
After repair it has been perfect and there is no moving element inside anymore and the IS locks without any jumping at all.
This is what I wrote in the other thread: