# Canon Confirms Light Leak Issue in the 5D Mark III



## DScience (Apr 16, 2012)

Oh Snap!
Canon Confirms &#8220;Light Leak&#8221; Issue in the 5D Mark III


----------



## sovietdoc (Apr 16, 2012)

Oh snap indeed.


----------



## STM (Apr 16, 2012)

Canon makes digital cameras? Who knew? I thought they stopped making cameras with the F1N (just kidding)


----------



## mfdrookie516 (Apr 16, 2012)

This is why I never buy something fresh on the market.  I got screwed on my first new truck... had like 6 recalls in the first year.


----------



## rexbobcat (Apr 16, 2012)

It's a good thing I rarely photograph in sheer darkness or with the top LCD on.


----------



## DScience (Apr 16, 2012)

rexbobcat said:


> It's a good thing I rarely photograph in sheer darkness or with the top LCD on.



If that was the only problem... However I have a good buddy who has been shooting with it for weeks, and he immediately noticed how his pictures were consistently exposed improperly, on more occasions than just dark conditions.


----------



## Dao (Apr 16, 2012)

rexbobcat said:


> It's a good thing I rarely photograph in sheer darkness or with the top LCD on.



But it said it strong light from the sun also affects the meter.


----------



## rexbobcat (Apr 17, 2012)

Dao said:


> rexbobcat said:
> 
> 
> > It's a good thing I rarely photograph in sheer darkness or with the top LCD on.
> ...



I would just add some small strips of black tape to the top then. lol.


----------



## imagemaker46 (Apr 17, 2012)

Another Canon mistake.  Problem with this major flaw is that it can't be fixed with a firmware update like the 1D mklll focus issues.  I would guess that it is going to be a complete recall on this body.


----------



## DScience (Apr 17, 2012)

imagemaker46 said:


> Another Canon mistake.  Problem with this major flaw is that it can't be fixed with a firmware update like the 1D mklll focus issues.  I would guess that it is going to be a complete recall on this body.



It appears to be their only option.


----------



## Overread (Apr 17, 2012)

They've already recalled one batch from distributors. 
So I suspect a full recall is going to be needed; plus I know some have not experienced this problem (might be something that is affected by manufacture tolerances and thus maybe not 100% of units are affected - explaining how pre-release builds got through testing) so it might wel lbe something that lingers a little in the second hand market.


----------



## 2WheelPhoto (Apr 17, 2012)

There's a solution of course:   Nikon | Home


----------



## Overread (Apr 17, 2012)

*looks for where he left the ban button*


----------



## sovietdoc (Apr 17, 2012)

From what I can tell, when they recall stuff people get their camera back within 5 business days.


----------



## Derrel (Apr 17, 2012)

So, for $3,499 in the USA (or a lot more in the UK and most of Europe), you get a cheap $389 EOS ELAN-type body that doesn't even offer a built-in eyepiece blind for use in the several types of situations where light coming in from the eyepiece can affect the meter's readings???? Are 5D-III users going to need to use that high-tech, $2.49 plastic Canon eyepiece cover thingie??

Introducing the Canon EOS 5D Mark III | Fake Chuck Westfall

Addendum:Oh-My-Gawd--this is a SERIOUS issue that appears worse than first described.  As the people at Petapixel stated, "Problem is, the issue isn&#8217;t limited to the LCD&#8217;s backlight in a dark room. Apparently any light (e.g. sunlight) shining onto the LCD screen can affect exposure". Look at the second video and watch the exposure fluctuate as a small piece of paper (smaller than a candy bar wrapper) is used to "shadow" the LCD...OMG...just plain old ambient light hitting the LCD is influencing the light meter...Holy Deity on a Cracker!!!

Petapixeldotcom, shows two short videos demonstrating serious light influence--with exposure values going from 10 seconds to 5 seconds, and from 6 seconds to 4 seconds...it appears that something as simple as light hitting the top LCD screen can cause the exposure to vary by around 50%...man...talk about bad engineering!!!

Canon Confirms &#8220;Light Leak&#8221; Issue in the 5D Mark III


----------



## TCampbell (Apr 17, 2012)

Who meters their exposure while pressing the LCD backlight button?  Seriously?!

Here's a quick firmware "fix":  patch the firmware so that whenever the light meter activates, the LCD back-light DE-activates.  That way it won't throw the exposure.


----------



## Overread (Apr 17, 2012)

Problem is that it seems the light seal that the LCD light gets though also allows sources such as strong sunlight to also penetrate the body and cause exposure problems.


----------



## Derrel (Apr 17, 2012)

I watched the videos on Pixelwhatever...the second video shows a scenario done in DAYLIGHT, with the lens cap on, to thus produce a long time exposure indication; when the man moved a small strip of paper near the front of the camera, on the lens side in front of the top LCD, the exposure shifted by basically 50%, depending on whether direct daylight was hitting the top LCD, or if the slight shadow the piece of paper was casting cut the light level reaching the LCD down a bit...so, it would seem that there is some type of "light leak" surrounding the LCD display...somehow it seems that light rays are influencing the metering through the LCD panel...


----------



## TCampbell (Apr 17, 2012)

I'd need to understand how they re-created this in daylight.

True light is typically measured in "lumens", "lux" or "foot candles", but cameras measure in "EVs" (stops).  Lux is measured linearly.  EVs are measured exponentially.  Each time the EV increases by 1, the lux doubles.

EV 0 = Lux 2.5
EV 1 = Lux 5
EV 2 = Lux 10
EV 3 = Lux 20
EV 4 = Lux 40
etc.

A daylight shot is EV 15 or Lux 81,920

If you're in an extremely dark place -- lets say it's EV 1 (which isn't completely black... but close).  You have 5 lux.  Now you expose the LCD to sunlight and note that it changes the exposure by half a stop (50% increase... a full stop would require a 100% increase).  The real amount of light leakage would have to be 2-3 lux to have this much sway on the exposure.

And yet... the sunlight exposed would be over 80k lux... but only 2-3 lux managed to leak in.  This could create a difference of 1/2 stop ... but ONLY at EV 1.

If you shooting outside in full sun (which is the only place where full sun should be hitting the LCD) and that same amount of light leakage occurs, the amount of lux is so tiny that it's basically not measurable.  (it would be 1/40,000ths of a stop).

I'm sure the light leakage is real.  But I don't think it's significant.  I can't imagine how the camera got through testing with all the prototype bodies that went to pros and nobody noticed a problem.  It seems as if the only way to measure the problem is in a contrived / non-real world test environment. 

Let me ask the question a different way (since I'm still shooting with a meager 5D II and don't have a III).  

If you stand outside with your camera at noon on a sunny day and meter a shot, can you get an EV 15 exposure reading with the LCD covered with light proof paper?  (e.g. ISO 100, 1/100th or 125th and f/16)   And... then removing the light-proof paper so the sun can now shower down light upon the exposed LCD... do you see the exposure change?

It's possible that I haven't seen the right video to demonstrate the problem and it's worse than I think.  But so far, the videos that I've seen demonstrating the problem can only do so if the camera is in an extremely dark place ... OR require that you do something to make the camera think it's in a dark place (put the lens cap on... put a back-cover over the eyepiece, and then turn on the LCD or flood it with bright light.)  

In essence, I suspect the reason this problem wasn't caught prior to production is because it doesn't impact real world shooting scenarios in any meaningful way.


----------



## DScience (Apr 17, 2012)

TCampbell said:


> I'm sure the light leakage is real.  But I don't think it's significant.  I can't imagine how the camera got through testing with all the prototype bodies that went to pros and nobody noticed a problem.  It seems as if the only way to measure the problem is in a contrived / non-real world test environment.
> 
> In essence, I suspect the reason this problem wasn't caught prior to production is because it doesn't impact real world shooting scenarios in any meaningful way.



Friend, however you want to look at it, however you want to justify it, Canon is possibly selling a 'defective' $3,5000 camera. It does not matter in the least if it isn't affecting ALL real world situations. If the fault in the meter system affects ANY situation, then that is simply unacceptable in my opinion.


----------



## unpopular (Apr 17, 2012)

??

isn't EV a measure of relative exposure not absolute energy?


----------



## 2WheelPhoto (Apr 17, 2012)

EV measures reflected light to simplify choosing among combinations of equivalent camera settings. Lux has not even been brought up by any of my professors so I doubt its really  relevant to our pics or a leaky Canon =)


----------



## TCampbell (Apr 17, 2012)

2WheelPhoto said:


> EV measures reflected light to simplify choosing among combinations of equivalent camera settings. Lux has not even been brought up by any of my professors so I doubt its really  relevant to our pics or a leaky Canon =)


EV (exposure value) is an absolute measure of light using a logarithmic scale.  You can directly translate between lux, foot-candles, EV, etc.  But you have to double the amount of light to get to each successive level of EV.  Think of it this way.  You're turned on a 1 watt light bulb in an otherwise completely dark room.  You have some given level of light.  Now you turn a 2nd 1 watt light bulb.  You've now doubled the light in the room.  That's a full stop.   That's a noticeable difference.  Now imagine you have 100 of these 1 watt lights.  You now add another 1 watt light.  This time there's no noticeable exposure difference because of the logarithmic nature of exposures.  You've only increased the light by 1% and that's not enough to effect exposure.If indeed you really ARE metering the light in a room with a single 1 watt light (one of the cases where the LCD light leak can be detected) then all you have to do is not meter WHILE activating the light on the LCD.  If, on the other hand, you are metering in full sun, then the light leak isn't strong enough to impact the exposure.Either way it seems the leak is too insignificant to really be a problem.People are ignoring that allowing light to enter through the viewfinder eyepiece ALSO impacts the exposure... Pretty much on every SLR camera (digital or film) featuring a built-in light meter. Photographers have always known this and accepted it.  The simple solution to that very old "problem" is to simple be aware of it and know to shield the light to get a more accurate reading.How is this any different?


----------



## 2WheelPhoto (Apr 17, 2012)

TCampbell said:


> 2WheelPhoto said:
> 
> 
> > EV measures reflected light to simplify choosing among combinations of equivalent camera settings. Lux has not even been brought up by any of my professors so I doubt its really  relevant to our pics or a leaky Canon =)
> ...



Thats great, but I'm trying to figure out what it has to do with the scope of this thread or a Canon leaking?


----------



## TCampbell (Apr 17, 2012)

2WheelPhoto said:


> Thats great, but I'm trying to figure out what it has to do with the scope of this thread or a Canon leaking?


Or maybe you're being deliberately obtuse?


----------



## 2WheelPhoto (Apr 17, 2012)

TCampbell said:


> 2WheelPhoto said:
> 
> 
> > Thats great, but I'm trying to figure out what it has to do with the scope of this thread or a Canon leaking?
> ...



No, just not into the thread-jacking. Guess I got reeled in though


----------



## Bitter Jeweler (Apr 17, 2012)

TCampbell said:


> EV (exposure value) is an absolute measure of light using a logarithmic scale.  You can directly translate between lux, foot-candles, EV, etc.  But you have to double the amount of light to get to each successive level of EV.  Think of it this way.  You're turned on a 1 watt light bulb in an otherwise completely dark room.  You have some given level of light.  Now you turn a 2nd 1 watt light bulb.  You've now doubled the light in the room.  That's a full stop.   That's a noticeable difference.  Now imagine you have 100 of these 1 watt lights.  You now add another 1 watt light.  This time there's no noticeable exposure difference because of the logarithmic nature of exposures.  You've only increased the light by 1% and that's not enough to effect exposure.



I just want to tell you how wonderful an explanation that is. :thumbup:


----------



## Bitter Jeweler (Apr 17, 2012)

DScience said:


> TCampbell said:
> 
> 
> > I'm sure the light leakage is real.  But I don't think it's significant.  I can't imagine how the camera got through testing with all the prototype bodies that went to pros and nobody noticed a problem.  It seems as if the only way to measure the problem is in a contrived / non-real world test environment.
> ...



Do Nikons come with a viewfinder cover? How often do you use it?


----------



## STM (Apr 17, 2012)

rexbobcat said:


> Dao said:
> 
> 
> > rexbobcat said:
> ...



Been there, done that with several Hasselblad backs where the foam which surrounds the dark slide needs replaced!


----------



## Derrel (Apr 17, 2012)

Pro-level Nikon cameras have had a built-in eyepiece shutter since the early 1980's. This is used whenever the camera is set for long exposures that will be timed automatically (as opposed to the exposure being pre-determined and srt manually in M mode), or when the photographer will not have his eye at the eyepiece and in any conditions in which stray light could enter the camera and cause the light metering system to be influenced by "stray" light entering the eyepiece.

As to the 5D-III, I stopped by Canonwatch.com to read their analysis of the problem, and to check their links. It seems that this issues might go BEYOND JUST the top LCD...EOS 5D Mark III light-leak issue UPDATE | CanonWatch

Ron Risman at _cameratown _did some extensive testing to trace down the problem and provides test shots to illustrate the issue. The bad news: the light leak on the 5D Mark III goes beyond the LCD panel (says Risman):
"What I discovered today is that *the Canon EOS 5D Mark III will give you a totally different exposure reading just by pulling your eye away from the viewfinder under normal indoor lighting conditions*. We&#8217;re not talking sunlight [...]. With normal room light, turning on the LCD&#8217;s backlight does not effect the metering like it did when I had most of the lights turned off &#8211; yet regular ambient light getting in through the viewfinder was enough to fool the camera&#8217;s metering system, which changed the exposure setting."


​


----------



## Bitter Jeweler (Apr 17, 2012)

So in the Nikon it's a feature, and in the Canon, light entering the viewfinder is a problem?

Sorry I am not tracking.


----------



## Derrel (Apr 17, 2012)

Bitter Jeweler said:


> So in the Nikon it's a feature, and in the Canon, light entering the viewfinder is a problem?
> 
> Sorry I am not tracking.



Apparently, you're misreading what I wrote...the idea that stray light can enter through a single lens reflex camera's eyepiece has been known about by camera designers for literally decades. Nikon has built something like one dozen camera models that have a simple "eyepiece shutter", with a small mechanical control located to the left of the finder eyepiece, to **ensure** that, in situations where light can enter the camera from the rear, through the eyepiece, and the camera is used remotely or with the user's eye NOT at the eyepiece, the photographer can simply close the eyepiece shutter, and prevent ANY light from coming in through the back of the camera. This is just really simple, basic, rudimentary camera engineering,and it probably adds about $20 to the cost of a professional Nikon body.

The idea that the LCD's own bacjklight illumnation is causing the meter reading to be off by 2/3 of a stop to 1 f/stop was discovered by numerous individuals who were TRYING to do tripod HDR work.

READ Ron's experience with doing HDR multi-exposures at night...whenever he'd turn on the LCD illumination to check the camera's settings, it would 'eff up the exposure values...

For the people who like to do star trail exposures, or night-time cityscape photos, using electronically-timed exposures, this represents kind of a serious design issue with getting the exposures messed up, either by light coming in through the eyepiece, or by daring to turn on the LCD illumination to check settings.

This isn't some Nikon vs Canon thing...it's just that Canon elected NOT to put an eyepiece shutter into a professionally-oriented camera that many people are going to want to do tripod-mounted or timed-exposure work with, which has virtually always,always,always meant shooting with the photographer's eye NOT anywhere near to the eyepiece.

As Ron 's tests showed, indoors, with two 60 watt bulbs, even THAT level of illumination moved the indicated exposure from 1/6 second with his eye at the finder, to 1/10 second with his eye away from the finder. As on can see by his video demonstration, that is not exactly the "strong daylight" some are implying is needed to influence the meter's light reading...if two 60-watt bulbs in a ceiling fan can mess up the exposure by 2/3 of a stop, the problem seems to be pretty easily-seen. Again...this is that $380 EOS ELAN body feature set the 5D series has always been plagued with rearing its head. The fact that the LCD screen's illumination can also affect the metering seems like a second screw-up. So there are TWO problems actually, not just one.

Canon will probably be able to figure out a fix though. Just like when the original 5D cameras had their mirrors fall off because the GLUE that held the mirror in its carriage failed...Canon designed a retrofit with two 25-cent metal clips to hold the mirror in place, and offered a free installation of the two, two-bit parts they SHOULD have used in the original design. Or the 1D Mark III with its AF system that refused to AF properly...they got that fixed in 18 months, then brought out a new model...or the 5D II with the black speckled dots all over the images shot in low light...this is yet another screw-up at launch. Found by paying customers. Not by beta testers or the factory's own engineers.

This issue seems to me like it would be the most damaging to tripod-based type of shooters doing long exposures, or those who photograph without their eye to the finder eyepiece, such as people shooting with remote releases.


----------



## Bitter Jeweler (Apr 17, 2012)

I get what's going on with the LCD thing. But as far as the viewfinder, mine came with a cover. Albeit a seperate part that you can lose if you are not careful.
I just don't understand that last bit in your post where the guy is complaining about a known issue with all SLR's


I will admit that I am glad I am not an early adopter. I bought a $3000 air powered hand engraver instead. LOL
New camera can wait.


----------

