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Author Topic: IS doesn't work  (Read 3605 times)

Giedo

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IS doesn't work
« on: January 06, 2007, 10:27:26 am »

I noticed on a new lens (70-200 f4 IS) that the IS on did not make any difference with or without it. Then I tried 2 other lenses and I found the same indifference between IS on or off.
Can it be my camera that is broken? (I own a Canon 20D)

Giedo
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Paul Sumi

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IS doesn't work
« Reply #1 on: January 06, 2007, 10:41:38 am »

Quote
I noticed on a new lens (70-200 f4 IS) that the IS on did not make any difference with or without it. Then I tried 2 other lenses and I found the same indifference between IS on or off.
Can it be my camera that is broken? (I own a Canon 20D)

Giedo
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How are you using the lens?  At fast shutter speeds you will probably not see a difference in sharpness.  Try a very slow shutter speed (1/8th or slower) at 200mm, hand held with no special support, to test.

Also - IS only works when the shutter release is half-pressed/fully pressed.  You should hear a faint whirring noise as it spins up (takes about 1/2 second).  Looking through the viewfinder as IS spins up, you should see the image stop wavering around and get much  more still.  The difference is very obvious unless you are very good at hand-holding telephotos.

Paul
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Box Brownie

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IS doesn't work
« Reply #2 on: January 06, 2007, 11:06:19 am »

Quote
I noticed on a new lens (70-200 f4 IS) that the IS on did not make any difference with or without it. Then I tried 2 other lenses and I found the same indifference between IS on or off.
Can it be my camera that is broken? (I own a Canon 20D)

Giedo
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Hi Giedo

I cannot speak about that lens but my 70-300 IS has a marked difference if I turn IS off.

When you say it makes no difference what do you mean?  Are you saying that all your shots at 200mm (for example) are blurry IS or not, or are you saying that without IS all your shots are nice and sharp, in other words you find IS unnecessary?

As noted by PaulS the IS works best with low shutter speeds, lower than you would normally use for the focal length.  For myself I have gotten good shots at 300mm with a shutter speed as low as 1/15sec.

Also, please be aware that IS stops camera movement not subject movement and indeed takes approx half a second to spin up and stabilise ready for the shot ~ that settling down is normally visble in the viewfinder.  Sorry if I have (overstated) the obvious;)

HTH
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Giedo

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IS doesn't work
« Reply #3 on: January 06, 2007, 01:09:33 pm »

thanks, but I'm aware of all this. I tried the slow shutterspeeds (1/4 th, 1/8 th, etc.) at 200mm... no difference between shots at 100%!
But the thing that struck me is that IS doesn't work on all 3 of my IS lenses. (and they used to work excellent!) Also you can't hear any whirling sound as you're supposed to...

So I thought: Maybe the lenses are fine, but my body does do sth wrong here. Could it be the body that jut does not give the right signals to the lenses?

Anybody?
« Last Edit: January 06, 2007, 01:10:35 pm by Giedo »
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howiesmith

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IS doesn't work
« Reply #4 on: January 06, 2007, 01:24:54 pm »

Quote
thanks, but I'm aware of all this. I tried the slow shutterspeeds (1/4 th, 1/8 th, etc.) at 200mm... no difference between shots at 100%!
But the thing that struck me is that IS doesn't work on all 3 of my IS lenses. (and they used to work excellent!) Also you can't hear any whirling sound as you're supposed to...

So I thought: Maybe the lenses are fine, but my body does do sth wrong here. Could it be the body that jut does not give the right signals to the lenses?

Anybody?
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I don't think the body "talks" to the lens for IS.
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Box Brownie

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IS doesn't work
« Reply #5 on: January 06, 2007, 01:26:37 pm »

Quote
thanks, but I'm aware of all this. I tried the slow shutterspeeds (1/4 th, 1/8 th, etc.) at 200mm... no difference between shots at 100%!
But the thing that struck me is that IS doesn't work on all 3 of my IS lenses. (and they used to work excellent!) Also you can't hear any whirling sound as you're supposed to...

So I thought: Maybe the lenses are fine, but my body does do sth wrong here. Could it be the body that jut does not give the right signals to the lenses?

Anybody?
[a href=\"index.php?act=findpost&pid=94148\"][{POST_SNAPBACK}][/a]

Sorry if I misjudged what you were saying.  It does sound like a failure of connectivity between the body and lenses if they used to work OK.

Have you tried cleaning the contacts on the camera body ~ I recall reading that a simple pencil eraser does the trick but how do you keep the debris out of the mirror box?  Lastly, I am sure the contacts in the body are sprung so maybe there is a problem with that aspect?

HTH
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Box Brownie

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IS doesn't work
« Reply #6 on: January 06, 2007, 01:29:31 pm »

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I don't think the body "talks" to the lens for IS.
[a href=\"index.php?act=findpost&pid=94152\"][{POST_SNAPBACK}][/a]

But it does provide power and there are only so many ways to provide data interface and power with the number of contacts.  As Canon have never (have they?) published how the system 'talks' to each other, anything potentially is possible?

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Paul Sumi

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IS doesn't work
« Reply #7 on: January 06, 2007, 04:33:36 pm »

Try cleaning the contacts on the lenses AND on the camera's lens mount.

But given the IS on all three lenses doesn't work, sounds like the camera may be at fault.

Have you tried the lenses on a different camera body?  Is the camera battery at full charge (IS really uses a lot of power)?  Does autofocus still work?

Paul
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howiesmith

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IS doesn't work
« Reply #8 on: January 06, 2007, 06:21:58 pm »

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But it does provide power and there are only so many ways to provide data interface and power with the number of contacts.  As Canon have never (have they?) published how the system 'talks' to each other, anything potentially is possible?


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Forgot about the power contacts.  Could be the cause of the common failure.

Does the USM have a seperate power connector?
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Giedo

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IS doesn't work
« Reply #9 on: January 07, 2007, 06:24:00 am »

My problem is solved. I don't know how, but IS now works again on all 3 lenses.
The only two things that I can think about are
1- I did not look properly/ dit not test properly (not completely unthinkable  )
2- My body was more or less drowned in torrential rains last summer but kept working allthough one of my lenses was completely fogged up. Maybe the contact points were showing some kind of corrosion and I didn't change any lenses for the last several weeks. As I started testing my new lens I switched a lot of lenses. Maybe that made the contacts clean again!?  

Anyway, thanks for all your thoughts.

Giedo
« Last Edit: January 07, 2007, 08:14:42 am by Giedo »
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