Canon confirms Canon EOS 5D Mark III LCD light impacts metering in extreme dark

by planetmitch5 Comments

Earlier we reported on what was being called a “light leak” and Canon now confirms that in extreme dark light situations, pressing the LCD backlight may impact metering. Please read the product advisory below.

We'll of course let you know when Canon issues a resolution statement.

Product Advisories

To Users of the Canon EOS 5D Mark III Digital SLR Camera

Thank you for using Canon products.

The phenomenon described below has been confirmed when using the Canon EOS 5D Mark III Digital SLR Camera.

Canon is now examining the countermeasures and once the countermeasures are decided, we will post the information on our Web site.

In extremely dark environments, if the LCD panel illuminates, the displayed exposure value may change as a result of the AE sensor’s detection of light from the LCD panel.

Affected Product
Canon EOS 5D Mark III Digital SLR Camera

Once the preparations are complete, we will be making an announcement on our Web site.

This information is for residents of the United States and Puerto Rico only. If you do not reside in the USA or Puerto Rico, please contact the Canon Customer Support Center in your region.

Please register the EOS 5D Mark III. By registering, we will be able to notify you via email when service updates are available. If you already registered, please ensure you are opted-in to receive the notification.

Thank you,
Customer Support Operations
Canon U.S.A., Inc


So, while we did agree earlier that there was a possible impact from the LCD light, it again doesn't appear to significantly impact most situations.


(cover photo credit: snap from the earlier article)


  1. Sucks that this problem exists, but I’m guessing the effect’s pretty small since it took this long to be noticed, and I’m guessing they’ll be able to fix with a firmware update.
    They should be able to measure how much of an affect it is and just apply a compensation for it. Hopefully ;)

  2. I don’t know if a update can fix physical light hitting the sensor, they could always just fudge it though & pretend they fixed it with an update. Tell the system to roll back the apature ”value
    ” when the light is turned on & it detects an aperture change at high iso. But of-cause you would know when looking at comparison shots.

    I’m intrigued to see how Canon will play this in the following days… Voluntary recall or some crappy cash rebate?

    1. Sounds like the light’s hitting the AE sensor (not the image sensor). And since they should be able to measure how much light that is, they should be able to apply ad adjustment for it.
      Also, somebody on another forum mentioned the idea of just having the LCD backlight turn off when the metering happens.
      Both seem like possible firmware fixes.

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