EF 24-105mm f/4L IS USM Image Stabilzer problem

[LesB]

I bought this lens a few months a go together with a 5D Mk111 body. I am convinced that there is a problem with the image stabilizer that causes image blur when I set the aperture to F5 or above. I have taken the lens to Canon 3 times and despite me demonstrating the problem they don't seem able to fix it. I know that a shutter speed of 1/10 sec is a bit slow for hand held but the comparison I made was between 2 photos both taken at that speed. I would be very interested to here from others who have this problem. Here is the test I did to demonstrate the problem.

1. Set the camera to 1/10sec at F5 or above. Set the lens to max zoom.
2. Take the first picture normally using a static subject with some clearly defined edges (such as text).
3. Take the second picture by first focusing with a half press, then press and HOLD the depth of field preview button to close the aperture, then take the photo.

With my lens, the first picture is blurred and the second is completely clear. This suggests to me that the action of closing the aperture when the photo is taken is causing the image stabilizer to lose lock. If the aperture is closed before the photo is taken (or if it is set to F4), the image is clear.

I have tried this lens on another body and get the same results. I also have a less expensive EF-S 15-85mm lens on a 60D and its stabilzer performs perfectly under these conditions.

Hopefully you can see the attached samples.

John

[Glenn NK]

I have used this lens at 1/15 second at various apertures with good success (and I'm old and shaky ).

It still works well after six years (although it isn't the sharpest lens in my bag).

Glenn

[benmar]

So in both cases are you giving the shutter button a half press, holding a moment to allow the IS to stabilize before making the exposure?

[Glenn NK]

So in both cases are you giving the shutter button a half press, holding a moment to allow the IS to stabilize before making the exposure?

In my case I use BBF - press and hold - the AI Servo focus is continuous, and the IS is already running when the shutter is pressed.  Maybe that's why my 5DII batteries don't last long. 

Glenn

[FredBGG]

JUst a thought.

The 24-105 is a heavier lens than the 18-55.

Could it be that pressing the depth of field preview button results in a steadier grip?

Have you tried "pretending" to press the depth of field button. You know press just to the side of the button....

[LesB]

Yes, in both cases I gave the stabilizer time to work before taking the picture. The only difference between the 2 shots is the closing of the aperture before the picture is taken rather than letting it close when the picture is taken. I have tried this many times with the same result so the law of averages should eliminate shaky hands. I should also mention that when I tried one of the service centre's 24-105 lenses the problem wasn't there and yet they fail to acknowledge it.

[francois]

John ,
Have you tried renting another 24-105 f/4 IS lens? I don't own this lens but I used it quite a lot and never noticed this issue. While I'm no expert, I can imagine that something like sticky aperture blades could cause problem similar to yours.

[LesB]

Well, after another visit to the Canon service centre, I think they have now fixed the problem. They said that they had to reload the firmware onto the lens and of course calibrate it.

[francois]

Well, after another visit to the Canon service centre, I think they have now fixed the problem. They said that they had to reload the firmware onto the lens and of course calibrate it.

Good to hear that your lens is fixed!