Canon 5D Mark III “Light Leak” Issue Alters Exposure by 1/3 of a Stop

A quick update on the “light leak phenomenon” on the 5D Mark III that Canon confirmed last week: after emailing Canon about the issue recently, photographer birdbrain received the following response:

Further to your enquiry we would like to inform you that we very recently (in April) have become aware of this and is now a known issue with the EOS 5D Mark III model. The AE sensor in the camera detects the light from the LCD panel when it is turned on and the exposure value will be altered. The change is not significant as it will be altered by approximately 1/3rd of a stop but can be noticeable. You can continue to use your 5D Mark III and the LCD screen can be turned off to receive the correct exposure.

The video above shows examples of what this 1/3 stop difference does for nighttime photographs. The issue definitely isn’t a huge one (don’t cancel your orders), but the 5D Mark III is a $3,500 camera and it’ll be interesting to see how Canon decides to deal with this flaw.

(via DPReview via Canon Watch)

  • Jørgen Kløvstad

    This is rather unfortunate

  • Mr.condolences

    is not a fault, previously demonstrated the sensitivity of the image processormuch higher in this DSLR

  • Mike Philippens

     Well…other camera’s (ie the new Nikon) don’t have this ‘feature’, so I’m pretty sure it is a fault. There is some sort of gap in the body.

  • Slash_Cynic

    Uh Nikons and other brands have this feature. Just no one is else is bitching.

  • Stuart St John Boreham

    A major UK pro supplier today told me that they were out of stock on 5D Mk3’s and that Canon had said they were going to stop supplying until the summer due to this issue. Interesting. And I was about to buy one…

  • guest.

    until there is a fix, couldn’t people just intentionally over-expose their photos by 1/3 if they are using the LCD panel light?


  • Sukiyaki12

    If Nikon has this feature then why does Canon have to issue a product advisory notice about it and investigate countermeasures?

  • Bo Reidler

    It is supposed to be a high precision tool that comes at a premium price. It’s an unfortunate blemish on the brand.

  • The Dude

    Amen to that.  And to the guy below me:  Canon issued a product advisory notice so that they could work on a way to fix the problem, hence your usage of the word “countermeasures.” Now, I know personally of a few Nikon D4’s having to be sent back for replacement because of the inability to properly lock focus.

    TL;DR Nikon has problems too, they just aren’t admitting to them/actively trying to fix them. 

  • Sandy Personette

    If this is such a flaw to stop shipments to major retailers, why wasn’t it noticed before now by all the “testers” of this camera?  You’d think that someone would have noticed.

  • 9inchnail

    Because the average photographer won’t see much difference between a normal exposure and a 1/3 alteration. Someone was propably taking a series of shots in manual with constant light and noticed that the light meter changed when the display was turned on. You don’t necessarily see much difference in the final images. Especially if you’re shooting outside in the sun, that meek little display won’t have much effect. Not that many people shoot in dark settings where this flaw becomes most apparent.

  • Daver

    It’s definitely a flaw and as a owner of a 5D Mark III I’m disappointed, but I seldom if ever use the LCD screen, let alone use the light and I shoot manual 99.9% of the time. So it should effect me. However this does reflect badly on Canon. After all it is a $3500 body. 

  • Kensettlephotos

    My understanding is that this will not affect photographers who use the camera  in manual exposure mode.

  • Daver

    Typo, I meant to say shouldn’t affect me. 

  • Almond

    Correct me if I’m wrong, but 15″ to 8″ isn’t 1/3 of a stop…

  • Bylica

    i just checked my 5dmark3 no problem at all during same exercise,purchased in london 

  • DB66

    Bought my 5D III in London, tested, only have this issue when the body cap is on…and who uses their camera with the body cap on????, have tested in “normal” use with 24-105,100-400L, 100L macro, ef 50mm 1,4 and found no issue

  • Zheng Stanley69

     It is not an issue at all in normal photography work situation, the
    object and the surrounding has to be dark for it to affect the ae. Even
    at f4, at 2 seconds iso 800 does not affect the ae metering when u turn
    on the lcd top light! with the lens cap off and view finder being
    covered. Is this really an issue??? at ISO 800, f4, at 2 seconds no
    change! I am surprised that people are really hyped abt this. the object
    you are metering and the surrounding has to be really dark for it to
    affect the ae metering!!!. My goodness and people are really getting so
    fussy abt this!! and who shoots with the lens cap ON?????????

  • Ceddy C

     Checked mine, it seems fine.

  • Uro_flow

    I tested my 5D MIII i did not observe this flaw