'...Early adopters say that light can leak through that spot and confuse the camera's Automatic Exposure (AE) sensor... and Canon isn't disagreeing with them. In fact, the company has admitted the issue today. "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," a Canon product advisory reads.'

Here is a link to the story:

Canon admits 5D Mark III backlight can confuse light sensor, is working on 'countermeasures' | The Verge (http://www.theverge.com/2012/4/14/2947278/canon-admits-5D-mark-iii-light-leak)

Here is a link to a video of the problem.

Canon 5D Mark III Light Leak Example on Vimeo

Tests carried out in Holland also have proven a 'light-leak' if using the Mk3 dark scenes. a link to the Dutch site is here:
Test: 5D Mark III 'Light Leak' bug | FotoVideo.nu Nederland (http://nl.fotovideo.nu/nieuws/27104/test-5d-mark-iii-light-leak-bug)

This small exposure error will not affect most users, but may affect some in extreme low-light, so it is worth mentioning I think. Nothing official from Canon yet, but feedback seems to point that they are working on the problem.

Yeah, what a boo boo for a major manufacturer, right on top of NAB too.

I wouldn't want to be on duty on their stand in Vegas, I'd go off and play the slots for a week.

Man Behind Lens: Canon 5D MkIII Light Leak Issue! (http://cyleow.blogspot.com.au/2012/04/canon-5d-mkiii-light-leak-issue.html)

Cheers.

I would imagine that it'll need a full product recall to fix this. Some discussions on the web suggest Canon might like to offer a "free fix for sharper video resolution" whilst the cameras are in and being taken apart ;-) Dream on!

This is partly because of the extreme low light capability of the camera & has zero implications for shooting video as it could only be an issue with long (multi-second) exposures in near total darkness.

Sure, unlikely to affect general video usage I agree but as someone who also shoots astro photography I'd not want this "wild card" with my exposures.

I think its a pretty embarrasing oversight by Canon on an expensive camera and one that I cannot imagine would not require a recall to fix - even if all they do is stick some black electricians insulation tape underneath the top LCD! I'd sure rather Canon fixed it than I did as I'm not the type to open brand new cameras and void a warranty.

Personally, despite this, I'm still thinking very hard about getting a 5DMkIII... or saving even harder for a C300.... since my much desired "C100" is nowhere to be seen, unfortunately :-(

Hi Andy, well there's always NAB .. contrary to Canons usual modus operandi, they might announce the C100 to take the heat off their 5D3 problem.

But would you buy a 5D3 before they fix it? You'd never be able to sell it if you can't fix it with a software update.

imo unfortunately their sales will soon dribble down to a stop.

Cheers.

Certainly, I will not buy a 5DMk3 until this is fixed by Canon.

I really hope you are right about a C100 but I'm very sceptical as I think Canon have shown they are not interested in the £4K to £8k price point that I have the funds sitting in the bank for. Sure, many will buy a FS100 or FS700 now, especially since a AF200 was not announced by Panasonic last night - but that's a discussion for another thread!

So does that mean that the resellers on Amazon who have new Cameras, despite being under the used category, will have to drop their price? Right now they are selling Body Only for around 3,800.00
I am not concerned with the light leak issue. I already selling gear right now in order to purchase a 5D3 by next week.

More haste less speed Brad. I'd wait to see what Canon is going to do about this issue and you can watch the Amazon prices at the same time. And are you sure they're not gray market bodies?

If you buy a faulty body and Canon fixes this issue by having a dealer recall, then 2 things .. you won't have your cam while it's being fixed, and if you don't, you won't be able to sell it for the market price later on .. as all the others will be fixed.

Cheers.

Personally, I think this issue is a good thing to be aware of, and easy to avoid the problem in real world shooting. No one would trigger the backlight during a long exposure. Heck, I don't use the feature anyway on my 5D2 and forgot it existed until this topic came up. I would recommend using Quick View rather than the top LCD for setting exposure in the dark.

I would only worry about this if I regularly shot long exposure light painting photos.

Some evidence is emerging on various photography forums that there are TWO types of LCD panels (the top one, not the back one) on the early 5DMkIII's already out there - maybe from different component suppliers that Canon is using?

One is a flexible/flimsy thing (there have already been some isolated reports of cracking/damage etc.) and one much more sturdy/soild, which I've read has a black edging lip all around it.

I have no idea (been too busy with work to keep up) if one type is more prone to this light leak thing than the other, but someone may be able to shed light on that (sorry for the pun).

Certainly, I will not buy a 5DMk3 until this is fixed by Canon.You couldn't buy one even if you wanted to. They are selling quicker than Canon can ship them. A colleague who does want to buy (light leak notwithstanding) spent yesterday afternoon on the phone ringing around all the major suppliers (CVP, Jigsaw24, Jacobs, Warehouse Express, Park Cameras etc etc) but nobody has any stock.

I have read that Canon have stopped shipping them whilst they deal with a firmware issue that causes problems with one of their lenses and no doubt maybe this issue too. How true that is I have no idea.

I saw a guy today in Huntingdon who has a MkIII and we talked about it for a while - since he had it hanging round his neck and I noticed it!

He is absolutely delighted with his (he is a Pro photographer).

MkIII or C300, that's the only dilema I'm pondering at the moment, even after all the "NAB excitement".

While playing with the new 4K imaging Canon 1D-C at NAB this past week, I spoke with a Canon representative about the 5D mk III (since my order is still waiting to be filled at B & H!). Ii asked about the light leak issue, and he brought up a good point. Most of us will never experience any issues with the light leak anyway, but he said to me, "Do you know how the problem was discovered? By taking photos with the lens cap on." I admitted to him that, like most people, I was unlikely to take many photos with the lens cap on! :-) That said, Canon is obviously aware of the problem. I also asked a representative of B & H, who was at the show, and asked in jest, what do I do with my back-ordered 5D mk III, now that a problem has been identified with it. He said, "All the cameras going out from B & H will have had the problem fixed." Of course, I have no idea if that statement is true, or not, but like I said, I don't foresee me ever taking images where this problem will show itself.

Oh, yeah, the 1D-C was impressive... but my understanding is that it will be extremely expensive... just a little less than the EOS Cinema C300.

Canon is offering customers a free hardware inspection starting mid-May in an attempt to quell any and all product confidence issues:

"...Under almost all shooting conditions (including dark environments) this phenomenon will not affect your captured images. However, if you would like Canon to inspect your camera, we will provide this service free of charge upon request beginning in mid-May. Please contact Canon using the information below to request service."

Affected Product
Canon EOS 5D Mark III Digital SLR Camera
*Products whose sixth digit in the serial number is 1 or 2 are affected.
For example,　“xxxxx1xxxxxx”　or “xxxxx2xxxxxx” ([x] represents any optional number.)

Canon link here:

Canon U.S.A. : Consumer & Home Office : EOS 5D Mark III (http://www.usa.canon.com/cusa/consumer/products/cameras/slr_cameras/eos_5d_mark_iii?pageKeyCode=prdAdvDetail&docId=0901e02480538fc7)

Canon has also just released firmware version 1.1.2 for the 5D Mk III camera, bringing with it the following improvements and bug fixes:

Supports a new accessory, GPS receiver GP-E2.
Fixes a phenomenon where a pink cast may develop over the image when the shutter is completely pressed with the camera’s power turned off (by the auto power off setting).
Fixes a phenomenon where the camera operation stops after one shot when shooting in High Dynamic Range (HDR) mode.
Fixes a phenomenon where the Shooting Date/Time in the EXIF data of the image shows a later time than the actual shooting time.
Fixes the time zone for the Samoa Islands.
Corrects errors in the Finnish menu screen.

Canon 5 D Mark3 Firmware link here:
Canon U.S.A. : Professional Imaging Products : EOS 5D Mark III (http://usa.canon.com/cusa/professional/products/professional_cameras/digital_slr_cameras/eos_5d_mark_iii#DriversAndSoftware)

I was reading about this but I don't think it's a major concern. When other camera bodies were tested, they have a similiar issue, even the 5d ii. I think it's just a major over-reaction by some.

_______________________________________
eMemories Productions | Wedding Video Sydney (http://www.ememoriesproductions.com)

I think this "problem" is redicules... Sure, I have not taken that manny photos in extremely low light, but the ones I done is not in an automode. I would use M and put the numbers I'll would like to use.
And I don't think I have ever turned the back light on, on any of my DSLR I use/used.

Maybe the camera is so light sensitive that the light that comes from the LCD panel at the top go though the Lens (not in the camera) and is enough to expose the shot ;) match tha Nikon :P

After suspending shipping of the 5DMkIII for a short while it seems 5DMkIII bodies are once again beginning to ship with this issue now fixed. According to this official Canon China webpage, and the translations I've read on some photography forums, all the fixed 5DMkIIIs bodies (or is it just inpected and tested ones?) will be shipping with a white dot on the inside of the card door, see the picture in the link below.

[Don't worry, it is a genuine Canon China link, just the characters show as a row of ???? on this forum]

?????? (http://www.canon.com.cn/support/announce/5868.html)

My camera is in the affected range, but I don't think I will do anything about it either. Seems like an over-reaction to me as well.

Sam, but imo your cams resale value will drop way down if you could sell it at all .. if you don't get it fixed by Canon.

Cheers.

Potentially higher resale value is the only reason that I would get mine fixed too. It's why I always keep the box & other bits & pieces too.

Yeah, I never quite understood what the big deal was over all this. I admit that I use my DSLRs more for video than I do photography, but I have shot a decent amount of low light photographer including night time lapses. The only time I have ever used an auto mode was if I wanted to do a timelapse of a sunrise or sunset. Even then, I would never have the backlight on or LCD. For the life of me, I have yet to understand when this would be a problem.

Yes, but having someone take your camera apart to apply a fix is not a risk free affair. I've seen enough service tech work to know that often they don't give a damn about your camera, and a stripped screw or two, or a misaligned panel or two would not really matter much.

Say you get an extra rattle after they reassemble the camera? Or the seams now have uneven gaps? That's not really a risk I'm willing to take for something that doesn't affect my functionality.

Here's a link from a non-rumor site...

LensRentals.com - The Fix is In (http://www.lensrentals.com/blog/2012/05/the-fix-is-in)

I'm asking Frankie at Canon UK if they're going to do the same thing over here.

Not that I'm bothered personally, but I can see the point of it downscaling the resale value if the mod isn't done.

UK announcement by Canon on this issue here:

EOS 5D Mark III (http://www.canon.co.uk/Support/Consumer_Products/products/cameras/Digital_SLR/EOS_5D_Mark_III.aspx?faqtcmuri=tcm:14-925652&page=1&type=important)

I haven't had any problem in low light.
Shot for several hours last Saturday night.

SuperMoon w/ 5DMk3:
SuperMoon 5.5.2012 - Tampa, FL - a set on Flickr (http://flic.kr/s/aHsjzcKyLL)
http://farm8.staticflickr.com/7214/7007347882_c2c8e73ab2.jpg (http://www.flickr.com/photos/63365637@N07/7007347882/)