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Rusty, Customer Service
Category: Digital Cameras
Satisfied Customers: 5990
Experience:  Digital media expert, Computer program and operating system expert
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Im using a canon 5d mark iii with an mpe 65mm lens and while

Customer Question

I'm using a canon 5d mark iii with an mpe 65mm lens and while the aperture setting on the camera display doesn't change, in the lens itself, each shot, spanning around four shots, darkens to almost black as you look through the viewfinder until there's a grating click and it goes back to bright and normal again, as do the photos. Unfortunately, I get one decent shot then the cycle starts over again. Any ideas? The lens and camera are both new. I had a canon 5d mark ii before, with another mpe lens and didn't experience these problems...
Submitted: 4 years ago.
Category: Digital Cameras
Expert:  Steve G. replied 4 years ago.
Hello there and welcome to Just Answer. My name is XXXXX XXXXX I will be assisting you today. I am an engineer with over 30 years of electrical and electronic training, repair and installation experience. I will try and answer your question accurately and precisely so that we can get you on your way.

It sounds like you have bracketing turned on. Turn it off. Go into your menu, find Comp Exp AEB and set it to 1 meaning only one exposure is taken.

That should fix it.

Let me know if it doesn't.


Customer: replied 4 years ago.

Its already on 1 unfortunately.... so its not that...

Expert:  Steve G. replied 4 years ago.
Ok, try this:
Use the Quick Control Dial to scroll to <Adjust dyn range>
Press the Set Button
Scroll to <Disable HDR>
Press the Set Button

Tell me if that fixes it.


Customer: replied 4 years ago.

Sorry, but its already disabled. sometimes half pressing the shoot button makes it open back to the correct position, always with a grating click- did I mention this is set to manual?

So, it's the aperture not returning to the correct position and seemingly almost getting stuck on the way back, yet its not damp, dusty.... it's new. the other mpe I tried also does the same, but not with my old mark ii

Expert:  Steve G. replied 4 years ago.
That is baffling. I'm not sure what this could be so I am going to opt out of this question which will allow other Canon experts to chime in.

Hold on.
Customer: replied 4 years ago.

Im still holding on... by the way, this problem gets worse when I stick on extension tubes, even though I've been using them qhuite happily for two months with the new camera....

Expert:  Esca123 replied 4 years ago.

Thank you for contacting JustAnswer.
No doubt Steve G. suggested the right things to do/check. Let me add a "just-in-case" step. Reverting the camera to its default settings. I am sure you would not fret about zeroing the camera if you could get rid of that annoying whatever it is. You may want to take note of settings that you would like to keep and set again after the reset.

Please see below the reset procedure:


I know, it's like a subterfuge, but if it works...

Please let me know.
Customer: replied 4 years ago.

sorry, but i tried this last week, it made no difference...

Expert:  Esca123 replied 4 years ago.
That was my one shot. I will opt out and make the thread available to other professionals. The best of luck to you.
Expert:  Rusty replied 4 years ago.
Hello, my name is Rusty. You are really describing a symptom of a hardware problem. Since the shutter must be completely black, the moving metal parts are touching. That is the part that needs to be lubricated as well. I think quality might have missed that step when releasing your camera. The grinding is definitely an indicator of the settings trying their best to get the shutter back to it's position, but it's not able to. This sounds like a manufacturer defect.

The other two experts were right on the money, but I suspected something mechanical due to the grinding noise. It could be a piece of dust, dirt, sand, etc..., lack of lubrication on the shutter, or a bad manufactured shutter mechanism.
Customer: replied 4 years ago.

how come the camera works fine with every other lens I have? and why does it get worse when I add on extension tubes to the mpe? the grinding click happens in the lens not the camera....

Expert:  Rusty replied 4 years ago.
Hmm, ok, how about the lens with another camera?
Customer: replied 4 years ago.

the 2 mpe lenses work fine with my other camera... with extension tubes too. so its very confusing- i just dont know what to do... and why should adding more extension tubes have such a deteriorating effect...?




Expert:  Rusty replied 4 years ago.
That is a very good question. My suspicion is the gears to operate the lens have been stripped a bit, and adding the extension tubes is making it work harder. Do you see any sign of wear?
Customer: replied 4 years ago.

theyre both new in the last two months, so, unlikely...

Expert:  Rusty replied 4 years ago.
I'm stumped. That combination is supposed to work just fine, and that is a unique symptom. I'll open your question back up so other experts can take a look. Don't rate my answer, and you won't be charged for my time. Sorry I couldn't help you better, and good luck with your lens.