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New Contributor
Posts: 3
Registered: ‎01-11-2021

Exposure not working for EF 24-70mm F/2.8L II USM Lens

I have Canon EF 24-70mm F/2.8L II USM Lens that I have been using for past few years. For the past 2 days, the exposure on the lens is not working correctly. The pictures are very dark in live view mode as well as actual photo. Even when I bump up the ISO to 3200 and shutter speed to 1/10 in an outdoor area, the lighting is barely visible.

 

I've tried my camera with other lenses and they work fine. So, I know for sure that it's something to do with the lens. Any ideas or suggestions would be greatly appreciated. Thanks!

Esteemed Contributor
Posts: 4,675
Registered: ‎02-17-2016

Re: Exposure not working for EF 24-70mm F/2.8L II USM Lens

Sounds like the aperture is stuck.

Honored Contributor
Posts: 7,892
Registered: ‎11-13-2012

Re: Exposure not working for EF 24-70mm F/2.8L II USM Lens

[ Edited ]

@kvbarkley wrote:

Sounds like the aperture is stuck.


Welcome to the forum.

 

Yes. Is the optical viewfinder dark when you look into it? If you look into the lens from the front do you see the aperture blades? Set Av to f/22 and press the DOF button while looking into the lens - is anything moving?

John Hoffman
Conway, NH

1D X Mark III, Many lenses, Pixma PRO-100, MX472, LR Classic
Esteemed Contributor
Posts: 3,253
Registered: ‎11-19-2017

Re: Exposure not working for EF 24-70mm F/2.8L II USM Lens

Greetings,

After testing with other lenses, this has "contact canon" all over it.  The lens might require service.  

~Rick
Bay Area - CA
~6D2(v1.1.0) ~Many Lenses ~DxO PhotoLab Elite ~Windows10 Pro ~EVGA RTX 2080 FTW3 Ultra ~Pixma Pro-100 ~ImageClass MF644Cdw ~LBP622dw
VIP
Posts: 13,855
Registered: ‎12-07-2012

Re: Exposure not working for EF 24-70mm F/2.8L II USM Lens

've tried my camera with other lenses and they work fine

It is unlikely it is a camera problem. But there are other things besides aperture blade fault. Flex cable for example. At any rate it’s a Canon issue
EB
EOS 1DX and 1D Mk IV and several lenses!
Respected Contributor
Posts: 1,390
Registered: ‎01-25-2018

Re: Exposure not working for EF 24-70mm F/2.8L II USM Lens

As others noted, the aperture blades aren't responding so it is something Canon service will almost surely have to address.  The one "trick" that might work is set the aperture to its highest number and tap the depth of field preview button (usually to the right side of the lens mount on most Canon bodies) several times.  This is telling the aperture stepper to cycle between it wide open and fully closed settings and SOMETIMES this will unstick a stuck aperture mechanism.  I don't have much faith in it working because this is generally only sucessful with a lens that has been sitting unused for a long period of time which doesn't sound like the case with your 24-70.

 

Rodger

EOS 1DX M3, 1DX M2, 1DX, 5DS R, 1D M2, EOS 650 (film), many lenses, XF400 video
New Contributor
Posts: 3
Registered: ‎01-11-2021

Re: Exposure not working for EF 24-70mm F/2.8L II USM Lens

Thank you John. The optical view finder is also dark when I look through it. Not as much as the lens but still darker than the lighting conditions in the room. I also tried setting the aperture to F/22 and present the DOF button but I don't see anything moving in the lens.

 

I did notice that the exposure compensation for the len is stuck at -2 and doesn't change even when I change the exposure setting to +2 in the camera.

New Contributor
Posts: 3
Registered: ‎01-11-2021

Re: Exposure not working for EF 24-70mm F/2.8L II USM Lens

Thanks for the trick Rodger but as you mentioned, it didn't work. I think my only solution would be send it out for repair.

New Contributor
Posts: 2
Registered: ‎01-30-2021

Re: Exposure not working for EF 24-70mm F/2.8L II USM Lens

This kind of situation I also face. But after reaching here I have no more doubt on this topic. So thank you very much, John. The thing is that the optical viewfinder is also dark when I look through it. Not as much as the lens but still darker than the lighting conditions inside the room. I also tried omegle setting the aperture to F/22 and present the DOF button but I do not see anything moving in the lens. I did notice that the exposure compensation for the lens is stuck at -2 chatiw and doesn't change even when I change the exposure setting to +2 in the camera. But overall thanks for this awesome guidance.

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