Is my L lens faulty??

chuck

chuck

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Name
Dayle
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I've got to be honest here, I'm really unsure as to how I've not notcied this before.
The only reasoning is that I generally shoot at lower appetures with my 70-200mm F4 L USM, however I'm noticing that at higher apperatures in AV mode the pictures I'm getting are hugely over exposed I have to dial down my exposure compensation massively to compensate and increase shutter speed to get the propper exposure - this isn't the case with my other lenses (18-135mm IS and 50mm 1.4) niether of these are 'pro' lenses so a part of me is thinking that it's simply something that changes when using higher end gear ???

But then why would it expose correctly lower down :shrug::thinking:

I think it's perhaps the aperture blades are sticking ?

If it is faulty, where would you suggest I send it for repair, I haven't had any of my gear go faulty as yet so I haven't really considered it.
 
Ok, to ask a possibly stupid question, if you're shooting in AV mode can the camera adjust the other settings to give you the correct exposure?

Or in laymans terms, when you look through the viewfinder is anything (usually shutter speed) blinking at you?
 
manualfocus-g said:
You can check the aperture blades by setting your camera to stop them down to f22 or so and look down the lens when you hit the shutter release.
Click to expand...

Or depth of field preview button if you don't want a picture of yourself :lol:
 
you should get the same reading on all lenses
i played with
18-200
24-105L
100L
50 1.4
Tamron 28-70 2.8 i think

and set the camera up to AV F8 iso200
and the speed was the same on all lenses set to the same focal length where possible
 
Or rather than hitting the shutter release, look down the lens in av mode pressing and holding the DOF preview button jog the aperture adjustment wheel up and down and you'll see the aperture blades moving in and out (if there's no problem), do it a good few times.

Could it be a fault with the meter on the camera?
 
(to jimmy B) yes the aperture blades do move but I can hear a ticking noise when they do, surely it should be a smooth motion? The shutter speed does change when I adjust the aperture but I have to adjust it by let's say 3 1/3 to get the right exposure. It's around f14 when it basically whites out the image unless I compensate loads....
 
Thank you, I would therefore like some suggestions as to where I should send it :)
 
chuck said:
(to jimmy B) yes the aperture blades do move but I can hear a ticking noise when they do, surely it should be a smooth motion? The shutter speed does change when I adjust the aperture but I have to adjust it by let's say 3 1/3 to get the right exposure. It's around f14 when it basically whites out the image unless I compensate loads....
Click to expand...

The ticking noise is normal when jogging it in DOF preview, all of my electric lenses do it, not sure if the L glass does though.

If it's blowing the image out but the aperture is closing to the correct stop I would have said it was something to do with the camera rather than the lens but strange how it only does it on that lens.

Have you got a second body or can you borrow a body off someone to eliminate the camera being at fault?
 
I can but the soonest possible time I can will be Tuesday I should think I will get back to you, in the mean time are there any specific settings that could affect it that I could try adjusting?
 
what happens to the exposure values Av/Tv/Iso
if you set at 135mm and then immediately use the 18-135 @ 135mm on the same scene
do you get the same exposure values and do you get the same image exposure

you could try setting manual and seeing what happens
 
I have just done as suggested above, at 135 tv mode and av and the images are dramatically different, with the 70-200 the images aren't what you'd ever want to use especially with an L lens. Shutter speed is adjusting in the same way with both lenses, and the images are the same up until maybe f8 which would be fine as I shoot currently however it shouldn't do this it must be faulty?
 
chuck said:
I have just done as suggested above, at 135 tv mode and av and the images are dramatically different, with the 70-200 the images aren't what you'd ever want to use especially with an L lens. Shutter speed is adjusting in the same way with both lenses, and the images are the same up until maybe f8 which would be fine as I shoot currently however it shouldn't do this it must be faulty?
Click to expand...

So both lenses are using the same shutter speed, and the aperture is set the same on both, but the L lens is overexposing? Sounds like the blades are only closing to f/8 or so and then getting stuck and not stopping down further :(
 
manualfocus-g said:
So both lenses are using the same shutter speed, and the aperture is set the same on both, but the L lens is overexposing? Sounds like the blades are only closing to f/8 or so and then getting stuck and not stopping down further :(
Click to expand...

there is a simple test for that. Set it wide open in Av, press DOF preview and hold it while turning the dial all the way to f/22. The blades should move a little bit with each click and towards the end there should be a pin hole left.
And yes, they make a little click noise.
 
Yeh the lens is over exposing without adjusting any settings, the camera is picking the same shutter speed at the same focal length with only me adjusting the aperture nothing is changed but the lens, doing the DOF preview test it is moving all the way down right to f32 little confusing that's its happening like that then when I take a picture its very different
 
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