5D3 Viewfinder Display Question

Haven't been able to find anything about this after searching on Google and the forums here about the viewfinder on the 5D3.

I just received a refurbished 5D3 from Canon Direct and started setting it up/testing it out and noticed that every time I point the camera at a bright light source or a very well lit scene, the viewfinder display (info in green) dims to almost nothing and is unreadable. As soon as I point the camera away from the bright light source, it returns back to normal. It almost seems like the display gets brighter and brighter and then cuts out as the scene gets brighter and brighter. This doesn't seem normal to me but I wanted to check in here before taking it up with Canon to see if anyone else's 5D3 exhibits this behavior.

Thanks in advanced!

The brightness of the information actually doesn't change. The ambient light is just washing your viewfinder out.

Staszek wrote in post #16894224
The brightness of the information actually doesn't change. The ambient light is just washing your viewfinder out.

That doesn't seem to be what is happening here. I am able to make the green info display blink on and off/go extremely dim just by slightly adjusting the frame to a slightly darker (edit: or lighter) light source. Haven't experienced this on any of my previous bodies.

Never seen that before in my two years of owner 5D3's.

Staszek wrote in post #16894431
Never seen that before in my two years of owner 5D3's.

Had a bit more time to play with and analyze the issue. It seems like the viewfinder has varying degrees of brightness that automatically adjust in steps depending on the brightness of the scene, as the green info display adjusts and gets to it's last brightness step, it goes completely dim on the last step and is unreadable. As soon as I move the viewfinder to a slightly darker scene and the viewfinder adjusts the brightness down a step, the green info display comes back on. Definitely seems and acts like a defect of some sort to me.

Any other thoughts why it would do this?

Seems like I was shipped a defective body and that a call to Canon is in order.

The viewfinder display should be constant brightness. Sounds like it's defective.

No, the viewfinder display should have a varying brightness, to adapt to the surroundings. But it should of course not throttle down at the end of the bright part of the scale. There it should be at maximum brightness.

Had the info display not adjusted to ambient light level, then it would have been blinding at dark scenes or very difficult to see in bright scenes (as the poster now experiences in this particular case).

Mine appears to be constant....or rather my eyes cant detect the dimming.

However, if Canon makes it variable, it should only dim with the ambient but not fade away when it's bright..sounds like there's something wrong.

The old Canon A1 had this feature.

The whole point is that it should appear constant, in spite of your eyes adjusting to the ambient. Your eyes close the iris in brighter surroundings, and the display should compensate for that, thus appear to be of constant brightness, even when it's not.

apersson850 wrote in post #16894588
The whole point is that it should appear constant, in spite of your eyes adjusting to the ambient. Your eyes close the iris in brighter surroundings, and the display should compensate for that, thus appear to be of constant brightness, even when it's not.

Learn something new everyday.

Like Aswald wrote above, it was more obvious in the A-1 and T90, which used the same principle with LED. But the steps between the different intensities were more profound in these models, so it was easy to see the display adjusting the brightness back then.

I just tried mine, and even though I have never noticed it before, I do see that the green LED numerals go dim in dark conditions and then get brighter in very bright conditions. I only see two levels of brightness as I move from dark to light.

The OP seems to have his camera wired in reverse as his gets dimmer in bright conditions.

msowsun wrote in post #16895233
I just tried mine, and even though I have never noticed it before, I do see that the green LED numerals go dim in dark condition,s and then get brighter in very bright conditions. I only see two levels of brightness as I move from dark to light.

The OP seems to have his camera wired in reverse as his gets dimmer in bright conditions.

+1

Mine works like Mike's! Bright in dim conditions, dim in bright conditions.

Oh dear...what's happening?

It sounds like it could possibly be a problem with the 'intelligent viewfinder display". It has a direct impact on viewfinder brightness for the 7D, 1DX and 5D3. Under normal operating circumstances it shouldn't be a problem with a good battery, but all manufactured electronics are prone to some level of problem.

Here is Canon's description of the IVD.

http://www.learn.usa.c​anon.com …_viewfinder_dis​play.htmlp

"The LCD overlay
Like the EOS 7D, both the EOS-1D X and EOS 5D Mark III use a transparent layer above the focus screen that can display black LCD markings as well as briefly illuminate these markings in red. Like many LCD panels, the beauty of this viewfinder display is that only the information that needs to show is visible and the finder can remain uncluttered for maximum ease of viewing the subject.

The LCD overlay does require a tiny amount of electrical power to operate. This is obviously no concern when the camera is turned on, but if the battery is removed the transmissive LCD suddenly loses a lot of brightness and contrast. This is perfectly normal and will return to full brightness once a battery is reinstalled in the camera (the camera doesn't have to be turned on; it only requires a functioning battery pack to draw power for proper viewfinder operation)."

The Intelligent Viewfinder Display is not found on: 40D, 50D, 5DC, 5D2, 1D3, 1D4 as a partial list. It is a newer introduction to Canon DSLRs.

Since it's electronic, it's entirely possible there is some sort of problem with the Intelligent Viewfinder Display.

Only other thing I could think of is a feature I'm not sure is on the 5D3: (this is from a 1D4 manual) Custom Function III-14 AF Point Brightness: 0: Normal, 1: Brighter makes the AF point light up brighter in red.

I understand the OP is talking about the green information displayed in the viewfinder (and not the AF points), but the transmissive LCD overlay and it's ability to lose brightness has always been a potential concern for over the traditional viewfinders found in most other Canon DSLRs that don't require power for normal constant and consistent brightness.