EF 24-105 mm f/4L IS USM Image Stable Problem

<p>I bought this lenses along with other Canon gears last year. Someone finds the photo sharpness with IS (IS on) of this lenses is worst than those without IS (IS off). Is this a known problem? If I return it to Canon, are they going to fix this lenses or send me another one? </p>

<p>What shutter speeds? if you're on a tripod, long exposures with IS on will give blurred images.</p>

<p>Canon repair, not replace.</p>

<p>It is tested on hand-held at 1/60 second on the long end of lenses. </p>

<p>Do you half-press the shutter release, GIVE THE LENS' STABILIZER MAYBE A SECOND TO STABILIZE, and only then press the shutter release the rest of the way? Or do you simply plunge the shutter release and let the camera sort it all out? If you do the latter, then you might get some blur from the IS engaging just as the shutter is opening.</p>

<p>Test your IS to make sure it's working. Look through the viewfinder and jiggle the camera gently up and down. Notice how the image moves in the viewfinder. Now half-press the shutter release and observe. The image will first jump just a bit, and then it will appear "glued" to the viewfinder as you jiggle the camera gently up and down. If the IS does that, then it's working properly, and it WILL improve the stability of your shots IF YOU USE IT PROPERLY.</p>

My 24-105 gives excellent results in terms of sharpness with IS turned on. As the others suggest, if the lens is on a tripod

with IS kept on, results will not be great, similarly, IS needs to be turned on by a half click first.

Whenever I've had poor results, it's been due to my failings.

However, there is a "but".

My lens was sent for repair at one point and came back giving some soft images. It had to go back for a second repair in

order to rerun it to full quality. If you bought yours used, there may be problems.

<p>I have had one IS system fail (not on a 24-105). But it was clear the unit as failing, as, intermittently, the image would stutter for long seconds.</p>

<p>By the way, 1/60 handheld, at the long end should give you fairly sharp results (still subject). If not, and holding the same way, you find the shots taken at 1/60 handheld with a 100mm lens to be sharper, you should be suspicious of the IS system in the 24-105</p>

A little late coming to this thread.

I have exactly the same problem. I could go into a long rant as to how I discovered it. But will spare you that,

Fact is, after 16 months of ownership, I discovered the phenomenon and was able to re-create it time and again.

 

Nothing to do with tripods !

The phenomenon results when hand held, always: Shoot a frame, approx 70 to 100mm FL; shutter speeds 1/100th to

approx 1/150th; shoot the same scene, first with I.S. on, then again with I.S. off. The first will be blurred when viewed at

100- 200% (centre of frame) and very obvious at those magnifications. With IS off, same magnifications, image is nicely

sharp (for hand held). It IS an obvious flaw, and personally I really wonder to what extent this is an issue on many others.

There has always been a controversial issue with this model of lens. There must be a million out there and almost as

many opinions about it. Strangely, this isn't so obvious at normal viewing, but so many people have stated that they find it

not such a great lens due to being not very sharp. True enough, I also thought it sometimes would be great, other times

wondering why the image just seemed off. It wasn't until I had a day out without my tripod (unintentionally), and looked at

the results and discovered this fault.

I tested three other lenses in store's after my discovery and detected the same thing on one other! Albeit to a slightly

lesser extent.

This isn't a test one would normally think of doing, and was only prompted to do so after that day of discovery, and I was

just totally amazed! To the extent that I tested again and again.

 

If I tripod mount it and with I.S. off, it's a beautiful lens, and quite sharp, as most people would expect.

 

I have since replaced mine with the 24-70 f4L I.S. What a difference. This lens is great.

 

So after all this, I then started re-looking at all my earlier "stuff" with that lens, and upon serious looking, there it is, right

from day one.

Thank you V WU, I now know I'm not crazy!

 

Derek.

<p>Derek, sounds like you had a defective copy. Mine does not behave that way at all.</p>

<p>I've been using mine since it was introduced; no problems to report.</p>

<p>Wow, I suspect this is a fault that can easily be fixed by Canon, especially if V WU can so concretely quantify the failure as Derek has done. IME, intermittent faults only have ~50% chance of being fixed, but if you can provide them with a detailed (and repeatable) fault description, they can almost universally repair something like this.</p>

 

Derek, I did controlled tests on my 24-105 when I first received it, testing at around 1/200 and 105mm there was very little

difference in MTF 50% between IS ON and IS OFF, well within measurement uncertainty.

 

Ref IS OFF tripod. 58 lp/mm

Handheld IS OFF. 50 lp/mm

handheld IS ON. 45 lp/mm

 

You can get to the 100% crops via a menu system.

 

The write up is here http://www.zen20934.zen.co.uk/photography/LensTests/IS_Tests/EF_24_105mm_f4L_IS_105mm/

 

I have not checked since to see if things have degraded, but I can only assume what you describe is a fault condition.

<p>Ok Guys, thanks for your input. Nice test report Lester.<br>

Time to send it in to Canon, see what they. Here is a small version sample of the fault I'll be sending with the lens.</p><div></div>

Hi Derek,

 

That looks quite marked, I assume these a 100% crops.

 

The only caveat I would have on those images is where the focus plane was, if you were using the foreground object as a

focus target the plane could shift around. Canon might suggest this.

 

I would recommend using a high contrast target all in a single plane to avoid that sort of discussion, newsprint is a good

choice.

<p>Here is my test of the EF 24-105 mm f/4L IS USM<br>

These were handheld at 20' The first was with IS OFF, the second was IS ON. You can see a marked difference. I am very pleased with this lens. These were, of course closely cropped, but nothing else done.<br>

<img src="https://dl.dropboxusercontent.com/u/12009366/IMG_2040%20105mm%20IS%20Off.JPG" alt="" /> <img src="https://dl.dropboxusercontent.com/u/12009366/IMG_2040%20105mm%20IS%20On%201.JPG" alt="" /><br>

</p>

<p>Derek,<br>

Looking at your last post with the two test shots it looks exactly like the IS switch is reversed.</p>

I can assure everyone that the I.S. switch is not reversed. Also, the focus point was assured at the time in that, I did not

move position. My left hand held under the lens with my thumb on the I.S. switch ready to switch it over as the two

sample were taken. I have several samples. Some taken fairly short distance (as is the one shown) and some from

several hundred yards. Doesn't make any difference. Always the same end result, at about the same level of blur.

 

The point here is, in my mind, how good the non stabilized version is. I'm not that stable any more and was surprised at

how well I was able to make these samples. So, with only approximately 2 or 3 seconds between my sample pairs, it

leaves little doubt as to the existence of the fault. The evidence is quite plain to see.

D.