Strange circle on viewfinder 7D

JonK wrote in post #13298612
Hm... I almost feel like I saw this on my 7D recently.

What meter mode and focus point are you in?

Jon, I don't think it matters which mode, because it is still there with the camera off and the batteries out - which makes it physical and not electronic, if you get my point?

Before or after you changed lenses did you happen to sit the camera so that it was pointed at the mid-day sun with the cover off the lens. This would especially be a problem if the lens was a telephoto and if it was aimed at the sun for several secods since the image focal plane is at the screen. It could have resulted in enough heat to somewhat "cook" the liquid or maybe warp the screen so that it has some internal stresses. You can see an example of the effect of stresses by poking your LCD monitor with a finger.

Still under warranty? I would call Canon ASAP if so.

Bill Boehme wrote in post #13298703
Before or after you changed lenses did you happen to sit the camera so that it was pointed at the mid-day sun with the cover off the lens. This would especially be a problem if the lens was a telephoto and if it was aimed at the sun for several secods since the image focal plane is at the screen. It could have resulted in enough heat to somewhat "cook" the liquid or maybe warp the screen so that it has some internal stresses. You can see an example of the effect of stresses by poking your LCD monitor with a finger.

Interesting idea. I suspect that the circle would not be completely spherical then. It is *completely* spherical - looks like a machine made circle. But still something to consider.
I guess there is nothing for it ... it is going to the local agents for inspection..

Isn't it obvious? Just like everyone else the aliens have gone digital. We didn't get the message when they were leaving them in wheat so they have moved on to electronic equipment. You will need to send the camera to Area 51 to get it sorted out.

You never answered the gentleman that asked if you bought the camera used. I agree it does look like someone swapped the focus screen.

Sdiver2489 wrote in post #13302274
You never answered the gentleman that asked if you bought the camera used. I agree it does look like someone swapped the focus screen.

I apologise. The camera was bought new. Also, I may not have made it adequately clear that the ring appeared suddenly during a shoot - after changing lenses from the 18-55kit to the Sigma macro. No telephoto lenses were used so that theory is out.

The camera has about 5000-5500 shutter actuations. Hopefully this clarifies the issue somewhat?

what you gotta do is to get a bright light, there should be a catch somewhere, flip it and the circle is gone. Try resetting after that. If not, service center is you only option. Although if it does not interfere with your shooting in any way then dw about it.

mikeblackburn wrote in post #13302289
I apologise. The camera was bought new. Also, I may not have made it adequately clear that the ring appeared suddenly during a shoot - after changing lenses from the 18-55kit to the Sigma macro. No telephoto lenses were used so that theory is out.

The camera has about 5000-5500 shutter actuations. Hopefully this clarifies the issue somewhat?

Does it appear with no lens on the camera? Does it appear with each lens you have now?

Ebwly wrote in post #13302308
what you gotta do is to get a bright light, there should be a catch somewhere, flip it and the circle is gone. Try resetting after that. If not, service center is you only option. Although if it does not interfere with your shooting in any way then dw about it.

Thanks... Could I ask you to clarify what exactly I am looking for? Not really keen to go poking around in there blindly.....
Appreciated.

Sdiver2489 wrote in post #13302321
Does it appear with no lens on the camera? Does it appear with each lens you have now?

Yes.. If you take the lens off and view the focus screen from inside the camera, you can see the ring on the screen itself...

Since it's there when you remove the lenses, it's clearly part of the camera's optical path.

It appears to be centred on the optical axis which makes me wonder whether it's other lenses in the system. _Maybe_ an element has shifted causing an internal reflection.

Have you tried adjusting the dioptre setting? Does it work normally?
Does the diameter of the ring change when you vary the dioptre adjustment?
Have you perhaps installed an anti-fog eyepiece?

If the answer to each of these is no, then the problem - if it is one - probably lies at the screen end. It is possible to remove the screen (look for instructions here - follow them exactly) which will let you determine whether it's the LCD or the screen.

7D has some fancy new screen which is pretty hard to remove. You gotta unscrew some screws and stuff.

I want to know what this is about only because I can't imagine what it is!