Canon 5dMkii Erratic Metering

[Marcus Geezer]

Here's a good one.

Last Saturday at a wedding one of my 5DMkii's just starting metering at about 3 stops over it should be. I shoot manual so not a show stopper but use the internal metering as a starting point and made it through the day with just a little more effort. Got it home, had a play, tried my 35mm, 70-200 and my 24-70 and all the same. Did a firmware update (long overdue) and it seemed to cure the problem.

Used it again the other day and it started again but this time about 2 stops over and now used it again today and it is about 3 stops. Have reset everything, checked through the menu's and just can't seem to find anything obvious.

How does a camera meter internally? It must somehow meter through the lens, bounce off the mirror and have a think inside the viewfinder area?

I'm guessing that something inside here isn't right but was wondering if possibly some dirt could have crept in over the wrong bit blocking erratically the sensor?

Before i send it off for repair, was wondering if anyone could offer a solution?

EDIT: Left the battery out for a while and tried it again and it works. Remember leaving the battery out for charging before I updated the firmware. Not sure if this is anything to do with this?

 

[buckas]

Using spot or evaluative?

 

[Marcus Geezer]

Using spot or evaluative?

Tried all modes in a number of different scenarios which mainly included even tones and lighting. I used my other camera to work out what it should be (which matched what the meter states) then used the faulty camera to try and meter the scene the same and it wouldn't. Always over exposed by about 2 to 3 stops.

 

[Canon Bob]

The metering sensor is in the top of the pentaprism housing and consists of a sensor array and a lens. If the lens drops out then your 3 stops over is about par for the course....I have a 5DII with a detached metering sensor lens and it overexposes by 3-4 stops depending which mode is selected. Turn the body upside down and give is a shake...hear a slight rattle?

Bob

 

[Marcus Geezer]

The metering sensor is in the top of the pentaprism housing and consists of a sensor array and a lens. If the lens drops out then your 3 stops over is about par for the course....I have a 5DII with a detached metering sensor lens and it overexposes by 3-4 stops depending which mode is selected. Turn the body upside down and give is a shake...hear a slight rattle?

Bob

Hi Bob,

I have tried shaking it and cant hear it rattle any different than my other one but considering this sounds like a very plausible explanation it sounds like I just need to get it to a camera repairer as soon as possible and let them look at it.

Can I undertake any other tests which would indicate this as the root cause?

Thanks.

 

[Canon Bob]

Try a shot in Liveview....it should come out okay as the metering doesn't use the metering sensor.

Bob

 

[Marcus Geezer]

Try a shot in Liveview....it should come out okay as the metering doesn't use the metering sensor.

Bob

Bob you are a superstar.

For the first time in my life used live view. Looked at the metering in the live view and it seemed to match what I think it should be and took a picture at the correct exposure. Took it off live view for the same scene and the camera metering was way off showing it would be way under exposed.

Sounds like you've nailed it Bob. Will contact a camera repair shop in the morning.

Thank you.

 

[Canon Bob]

You're welcome Marcus...sadly it doesn't actually fix anything.

Bob

 

[Marcus Geezer]

You're welcome Marcus...sadly it doesn't actually fix anything.

Bob

Fixed no... but at least I know what it most likely wrong. Before your post I wasn't sure if it was hardware, software; or even user error.

Thank you again.

EDIT: Sent to Fixation. Hope is for a quick turnaround!