I'm sure some of you have heard the discussion that started on Saturday, but there's a minor issue that has been found with the Canon EOS 5D Mark III metering system when shooting in pitch black (or shooting with the lens cap on).
I debated about even reporting it, because some people have blown this way out of proportion, but it seems I really should at least let you know about it. My gut reaction was that posting about it might further inflame the passions, but I'm erring on the side of reporting it so at least you're aware of it.
First, let me say it isn't a “light leak” (which is what everyone is calling it – not my words) which implies that light is getting into the sensor and ruining your photos. In this situation, the light may be leaking thru the top LCD on the Canon EOS 5D Mark III and altering the reading the exposure meter is seeing.
Some of the reports
Here's Ron Risman's test as an example:
Ok, now, if you look at the videos – the vast majority of them are showing the 5D3 with the lens off and the body cap on, or with the lens on but the lens cap on – to make it really really dark. And yes, even on my Canon EOS 5D Mark III, I see the change in the exposure. Note: you also have to have the viewfinder cap on so there's no light coming in thru the viewfinder (which is a known issue – which is why they provide the cover already attached to the strap when you buy it).
First, I'll give you the summary:
- Yes, with the cap on, there is an exposure change when you press the top LCD backlight or put a strong light on the LCD
- Canon is aware of the reports and is looking into the situation
- In my testing during the day, there is no exposure change
- In my night testing, I couldn't see any impact to the exposure
- There may be some impact to timelapsers – but they shouldn't be putting a light on the camera in the middle of a sequence any way!
Yesterday – I took the time to go outside during the day and test. There have been several reports (if you read the threads above) where people say their Canon EOS 5D Mark III is underexposing when they are out in bright sunlight and it exposes properly in shade. I found this hard to believe so I went outside to check. First, I wanted to make sure that the scene wasn't changing (obviously if the scene or lighting changes, the exposure would change right? D'oh!). So I found a brick wall on my neighbor's garage and I could be in the shade of a tree and then in sunlight. I did see there was an exposure difference between sun and shade! Oops – soon I discovered that when I moved into the sun, there was some light getting on to the lens – thus invalidating the test… silly boy!
So I turned around and faced away from the sun and pointed my camera at the perfectly clear blue sky. I'd get a very consistent reading off of that! Plus, the sun would be directly shining on the top LCD! Guess what? I got the same exact exposure every time! I covered the top LCD… no change. I turned on the LCD backlight (which I couldn't even see in the sun)… no change in exposure.
I also went out about 10pm last night when it was completely dark and there were no clouds (here in the city, we get a brighter sky due to the lights when clouds are present).
I put the camera on a stable surface and pointed it at the back of the neighbor's house which was pretty dark. I set the ISO to 800 because that is what everyone said they were doing with the lens cap on tests (but it doesn't really matter – with the cap on, you can see changes at all ISOs). I noted the exposure (1.6 seconds) with the LCD light off… then I took the photo. Then I turned the LCD light on – no difference in exposure. I covered the LCD with my hand and covered the viewfinder (there was a single light over me on the patio) – no change in exposure.
I tested for about 15 minutes pointing the camera at different scenes and frankly I couldn't find any consistent changes to the meter readings under these night time shooting conditions. I didn't take a video cam with me so I don't have the documentation, but I was satisfied that under my normal testing, I didn't see any issues.
While I agree that Canon should (and is) investigate this issue, I haven't yet found any video proof that there is a problem for either full sun or nighttime shooting. People say they see something, but without seeing the conditions, how are we to know if it is an accurate test? (And yes, I can see people saying the same thing about my tests since I didn't take a camera… but I'm a busy man and didn't want to take the extra time on editing and uploading).
There are people demanding a recall and claiming this is yet another example of poor quality from Canon, but they're yelling without anyone fully testing the situation! Calm heads should prevail here. Nobody should change their buying strategy nor should they be returning their camera to Canon. Let's see what Canon finds – I'm sure they've got excellent testing procedures.
(cover photo credit: snap from the video)