Canon Confirms “Light Leak” Issue in the 5D Mark III

Earlier this month, reports started emerging that Canon’s new 5D Mark III DSLR has a “light leak” issue. Photographers found that turning on the LCD backlight in a dark room directly affects the camera’s metering system (as seen in the video above). Canon published a product advisory today acknowledging the issue, saying,

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.

The phenomenon […] 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.

Problem is, the issue isn’t limited to the LCD’s backlight in a dark room. Apparently any light (e.g. sunlight) shining onto the LCD screen can affect exposure.

Here’s a video that shows how sunlight shining down onto the LCD affects the camera’s metering:

Canon has quite a mess on its hands if it’s unable to address this issue in a simple manner — it doesn’t seem to be a problem that a firmware update will be able to fix.

(via CanonWatch)

Update: Mitch points out that in the second video the user has the lens cap on, so the camera “thinks” it’s in a dark environment.

  • Craig Cooper

    I tried this on my 60D and yep its also affected but more noticable is when you shine a torch inside the viewfinder. In the old film days when you were’nt behind your camera you had to close the viewfinder door to stop light entering the camera

  • Craig Cooper

    Thanks for testing and notifing us. More noticable is shining a torch inside the viewfinder. In the old film days cameras had a viefinder door to stop light leaking inside the camera.

  • Julian Sylar

    YOU obviously don’t work in a studio.

  • Flgraphics

    no excuse for this on a camera of this level. Big screw up on Canon’s part.

  • HD Cam Team

    Do you say that 60D and 7D also shift metering when you turn top LCD backlight on in dim light?

    Even when some people said this issue happens with 5D Mark II, it does NOT happen in the bodies we’ve tested.


  • Voltaire

    Agree with HD Cam Team; Sandra, I question whether you are doing the test properly.  I do not have a light leak with any of my other Canon cameras.

  • Markus Haznier

     Nikon should do the same about the oil sprays over the D7000 sensor, instead just pretend that this problem doesn’t exist. And I just saw in Nikon Rumors forum, someone with a similar problem in a D800.

    And some samples of oil in D7000:

  • Three_fitty

    Awww bless :) I don’t think dust on a sensor has anything to do with making a camera which doesn’t meter properly in certain scenarios.

  • Onkelfut

    Only people who bought a camera they in reality couldn’t afford are pissed!

  • HenryT2

    I agree this is not a big problem in a real world sense, however, Canon has the D800 to deal with. If it weren’t for my previous small investment in peripherals, I would probably have bought a D800. They’re both AWESOME and really pretty evenly matched, but I think the D800 seems just tiny bit little better (pros and cons numerous, but tie goes to image quality).

    When you buy a $3000+ camera that is already so close to the competition, any little flaw might make you rethink your decision. I know I am actively considering returning mine. Actually kinda silly, but they really are SOOO CLOSE and it was a tough decision not to jump ship. Honestly, the only thing that kept me from jumping ship and is keeping me from doing it now is the hassle of selling off my 2 lenses and a flash, and now, returning it and waiting for delivery of D800.

  • NicRokans

    Canon should have removed the top plate LCD years ago. As soon as we could view and adjust our shooting parameters via the quick menu and rear LCD the top plate LCD became an inferior and un-necessary piece of junk that was surplus to requirements anyway. You won’t see a top plate LCD on the 1 series cameras.
    Buying a camera within the first year of its release is something you do at high risk of paying top price and effectively getting a beta product in my opinion. Far better to wait a year for all the faults to be found by users then accepted and rectified by the manufacturer.
    Not only will you get a faultless design but you’ll also get it for much less than the original price.
    Light leaks have also been reported on the G1X camera. Canons most recent response to this problem was that they recognise there is a fault but are not going to do anything about resolving it. Not acceptable Canon.

  • Ivan

    As the vidoes showed you might get 1 stop under if the Sun shines on the top LCD – but only if your original exposure was 10 seconds. 10 sec in the bright sunlight? possible, but not that often happens in real life. I realy doubt the exposure changes when shoting a normally lit scene. Only when you shooting something very dark… Still, it needs to be fixed, I agree.

  • Ivan

    Tried it on 60D.
    Lans cap on, viewfinder open, dimply lit room: ISO 400, 5.6, 8″ – no change on pressing backlight button.
    Lens cap on, viewfinder closed by the stock cover, dimply lit room: ISO 400, 5.6, _30_” – no change on pressing backlight button.
    So, there is an issue with 5D MkIII, but it is likely lot less sensetive than how tight you put your eye to the viewfinder.

  • HD Cam Team

    It doesn’t look like “normal” dust. He said “oil sprays” and indeed it looks like that.

    The fact that Nikon doesn’t admit a problem, is somewhat related to this post, although not directly related to the issue mentioned on Canon 5D Mark 3.

    Canon seems to be more responsive to customers requests and complains than other companies. That’s a VERY good point for Canon, even when making some mistakes they don’t pretend the problem doesn’t exist (although sometimes it’s not easy, we must push and spread the news, so the evidence reaches lot of people)

  • Jin C

     My 5D2 bought brand new three months ago exhibits the same behaviour. No light in the surrounding, lens cap on, tight cover on the viewfinder, ISO 640, f1.4, exposure compensation 0, Av reading without the top LCD light is 15 seconds. With the LCD light, I get 13 seconds.

  • Three_fitty

    I’m talking about the D800 which is the pro body. The pic is dust and it’s a one off. Throwing mud when your in the **** won’t help you resolve this mess.

  • Jürgen Aerts

    messed up?? Well, those mole and prairie dog shooters will be of by a percentage, not in full stops. 2 seconds on a 10 tot 15 second metered time isn’t even 1/3 of a stop.

  • R Trubka

    I just tested this on my 5D Mark III and don’t see the problem. In a dark room I set the camera on manual and set the aperture, ISO and shutter speed such that I got proper exposure, then I hit the LCD light and saw no unusual change in the metering. Am I missing something or is this problem perhaps not affecting all bodies?

  • Simon Clark

    I’ve got an LCD screen on top of my 1D Mk3. You obviously know little about the excellent Canon range of cameras. I believe that good cameras are good cameras whoever makes them!

  • Stefanie Daniella

    Use the image sensor to determine exposure (ExpSim LV in Full M/M-ISO) of the entire FOV instead of using the AE metering sensor to spot/area only various multiple points in either AE/AEB modes of only part of the FOV.

    i.e. use newer digital methods instead of older film SLR methods (which are less accurate and less representative anyway).

    beside, why have a LCD light triggered AE lock, when it makes more sense to do AE lock manually BEFORE confirming on the top LCD panel?

    an additional idea for the future:

    I’ve always had trouble using the top LCD panel if my dSLR was already tripod mounted, and set up physically higher than my eye-level.  I couldn’t swivel the camera and spoil the composition (especially shooting/framing in extreme low light of ‘just’ moonlight).  worse, having the fixed LCD didn’t help either, as it couldn’t swivel downwards so i could look at the image LCD.

    many times i want to do extended shooting perspectives where the tripod mounted camera is well above and apart from my standing eye-level so neither fixed image LCD preview or fixed top LCD panel are viewable at all.  one shouldn’t have to tether a cumbersome third-party monitor just to see something that could be a modular compact robust hi-res VASS (Vari-Angle Swivel Screen) that is ‘built-in’ on PowerShots and the 60D/600D.  I much prefer a DUAL image screen where one can optionally mount a modular VASS.  If the Modular VASS is 3.2″ complement to the standard fixed 3.2″ LCD, one could allow for extra ‘previewing’ real estate to cover ExpSim LV simultaneously for the Image Preview as Live R-G-B histograms or Custom White Shift [B-A-C-M ‘single point’ values] during exposure-iso-color adjustments.

    such Modular VASS can also double as a ‘super-preview-remote-controller’ with optional extended tethering.  this way it wouldn’t be as bulky as something as large as, say, an iPad.

  • O Magnifico

    My cannon 30 D  , 40D,  5DMkII, doesn’t have the problem. My 5DMkIII yes!!

  • A. Lurker

     If you use Nikons why aren’t you writing them instead of preaching here? If you don’t use Nikons why do you even care?

  • NWFL Conservative

    Use NIKON, problem fixed.

  • macc

    Glad I did not buy it… won’t be buying until every current 5D111 is recalled and replaced with something worth the cash they want us to spend… having said that I would not buy it even for $100 with this or any problem… just not good enough

  • RonD

    Where this is showing up on the Mark iii and not other Canons, could it be a result of the fact that only the Mark iii is sensitive enough to detect the very low light levels resulting from this leak?  
    Either way, it’s concerning enough to follow how this plays out, but this hasn’t stopped me from getting consistently great images with the camera.  In the end, it’s those practical consequences that really matter to me.

  • Pierre

    The problem is, either Canon never realized the fault AT ANY TIME in the manufacturing process, which is very worrying from “such a brand”, or they realized it and still launched the product, which is very worrying  from “such a brand”… 

  • Sandra Chung

    Yup. Tested it with the 40D, the 60D, 5Dmkii and the 7D, and husband and I double checked.  He did it and I would watch, and vice versa. All four cameras did the same thing.

  • Sandra Chung

    Yes, I’m doing it ‘properly’. Again, it’s not a ‘light leak’, its a quirk, and it probably doesn’t happen with every Canon camera in the world.

  • Sandra Chung

    It’s probably not affecting each and every Canon camera in the world, but I can replicate, and have replicated the glitch. And in real world terms, it’s a non-issue. It doesn’t make an iota of difference when taking a photo.. or at least hasn’t with any of mine on either of the 4 tested cameras.

  • Sandra Chung

    Excuse me, but it happened with my 60D. It’s not an issue with the 5DMKiii. Or if it is, it’s an issue with all of them with the LCD window, but doesn’t affect them all.

  • Sandra Chung

    But it IS showing up on other Canon cameras.

  • Sandra Chung

    My 40D, 60D, 7D and the 5DMkIII does it. And I replicate it 100% of the time with each one.

  • HD Cam Team

    Weird. The 5D Mark 2 we’re using doesn’t show that inconvenience in any situation and it was bought in 2009.

    In the case of 5D3 it does seem to be a VERY small light leak through the top LCD panel, since it also happens when you’re in very dim light and illuminates the top LCD with a led flashlight.

    By any chance did you test your cameras with a flashlight too?


  • C C

    Why spend money on extensive testing when Canon (or any company) has you guys who do such a great job testing AND coming up with great solutions? On a more serious note, inhouse testing will have its own blind spots.

  • Guest

    Mine is underexposing in all kinds of situations, no matter which metering method I use. I didn’t pay £3,000 for a camera to have to chimp it and look at the LCD then adjust exposure accordingly. This is my first pro Canon, and I’m not pleased. Brilliant camera in so many other ways. This is a real shame.

  • Guest

    With all the attention on this website and others, there are a whole lot of potential buyers that will postpone the purchase of this camera indefinitely until this issue is resolved. And, whether or not this is a problem of negligible or catastrophic consequences, most people are not going to put down $3000+ for a camera that is getting negative press. That’s just human nature. I for one was looking forward to buying this when it became readily available. NOT NOW. I think I’ll wait and see how Canon resolves this issue. ARE YOU LISTENING CANON?

  • Stoney-B

    I think Canon should just repair this issue as soon as possible, the price that someone pays for a camera of this quality deserves it. I was saving up to purchase this camera since I missed the opportinty to get the Mark II. There are enough complaints from Canon Users about the price of this 5D MK III upgrade anyway. In this tough economy today, we cannot afford to give Canon our hard earned money, so they can just fix this problem the cheapest way possible, so I say to Canon, take care of the Professionals that have supported you thoughout the years!!!

  • Ffaria12

    estes grupos canonzeiros da vida que compraram mar3 ta ferrados,ou seja quase 10 mil contos de reis por ralo abaixo heheheheh kkkkkkkkkkkk

  • Paisan

    Can you post the video so people will stop arguing about whether the 40D, 60D, 7D etc. are having the same issues for real?

  • Paisan

    And Can you post the video showing your 30D, 40D, 5dmkii don’t replicate this issues?

  • Mark

    Just dropped my D7000 off at a Nikon Service centre to have the oil problem fixed under warranty !  It’s the aperture mechanism and is a known/accepted fault !

  • HD Cam Team

    Mark: good to know that you get it fixed by warranty.

    Is the oil coming from the aperture mechanism of the lens you use (kit lens?)?


  • mark

    Its the mechanism inside the body that operates the lever on the lens. Its just at the side of the sensor and shutter mechanism. I use 17-55 f2.8 glass so definitely not a kit lens nor are my primed and they don’t affect my Fuji s3 pro either. No one is throwing mud or **** lol